Converter to Polymer2 classes.

See readme.txt for more information about usages.

Change-Id: I60843b32bc56faa04ad2b70898ab1f5535a2ad71
diff --git a/tools/polygerrit-updater/.gitignore b/tools/polygerrit-updater/.gitignore
new file mode 100644
index 0000000..8619a37
--- /dev/null
+++ b/tools/polygerrit-updater/.gitignore
@@ -0,0 +1,3 @@
+/.idea/
+/node_modules/
+/js/
\ No newline at end of file
diff --git a/tools/polygerrit-updater/package-lock.json b/tools/polygerrit-updater/package-lock.json
new file mode 100644
index 0000000..9256997
--- /dev/null
+++ b/tools/polygerrit-updater/package-lock.json
@@ -0,0 +1,18 @@
+{
+  "name": "polygerrit-updater",
+  "version": "1.0.0",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "@types/node": {
+      "version": "12.7.12",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-12.7.12.tgz",
+      "integrity": "sha512-KPYGmfD0/b1eXurQ59fXD1GBzhSQfz6/lKBxkaHX9dKTzjXbK68Zt7yGUxUsCS1jeTy/8aL+d9JEr+S54mpkWQ=="
+    },
+    "typescript": {
+      "version": "3.6.4",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.6.4.tgz",
+      "integrity": "sha512-unoCll1+l+YK4i4F8f22TaNVPRHcD9PA3yCuZ8g5e0qGqlVlJ/8FSateOLLSagn+Yg5+ZwuPkL8LFUc0Jcvksg=="
+    }
+  }
+}
diff --git a/tools/polygerrit-updater/package.json b/tools/polygerrit-updater/package.json
new file mode 100644
index 0000000..3609dad
--- /dev/null
+++ b/tools/polygerrit-updater/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "polygerrit-updater",
+  "version": "1.0.0",
+  "description": "Polygerrit source code updater",
+  "scripts": {
+    "compile": "tsc",
+    "convert": "npm run compile && node js/src/index.js"
+  },
+  "author": "",
+  "license": "Apache-2.0",
+  "dependencies": {
+    "@types/node": "^12.7.12",
+    "typescript": "^3.6.4"
+  }
+}
diff --git a/tools/polygerrit-updater/readme.txt b/tools/polygerrit-updater/readme.txt
new file mode 100644
index 0000000..2b2cea8
--- /dev/null
+++ b/tools/polygerrit-updater/readme.txt
@@ -0,0 +1,56 @@
+This folder contains tool to update Polymer components to class based components.
+This is a temporary tools, it will be removed in a few weeks.
+
+How to use this tool: initial steps
+1) Important - Commit and push all your changes. Otherwise, you can loose you work.
+
+2) Ensure, that tools/polygerrit-updater is your current directory
+
+3) Run
+npm install
+
+4) If you want to convert the whole project, run
+npm run convert -- --i \
+  --root ../../polygerrit-ui --src app/elements --r \
+  --exclude app/elements/core/gr-reporting/gr-reporting.js \
+     app/elements/diff/gr-comment-api/gr-comment-api-mock.js \
+     app/elements/plugins/gr-dom-hooks/gr-dom-hooks.js
+
+You can convert only specific files (can be useful if you want to convert some files in your change)
+npm run convert -- --i \
+  --root ../../polygerrit-ui
+  --src app/elements/file1.js \
+      app/elements/folder/file2.js
+
+4) Search for the following string in all .js files:
+//This file has the following problems with comments:
+
+If you find such string in a .js file - you must manually fix comments in this file.
+(It is expected that you shouldn't have such problems)
+
+5) Go to the gerrit root folder and run
+npm run eslintfix
+
+(If you are doing it for the first time, run the following command before in gerrit root folder:
+npm run install)
+
+Fix error after eslintfix (if exists)
+
+6) If you are doing conversion for the whole project, make the followin changes:
+
+a) Add
+<link rel="import" href="../../../types/polymer-behaviors.js">
+to
+polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown.html
+
+b) Update polymer.json with the following rules:
+  "lint": {
+    "rules": ["polymer-2"],
+    "ignoreWarnings": ["deprecated-dom-call"]
+  }
+
+
+
+5) Commit changed files.
+
+6) You can update excluded files later.
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/funcToClassBasedElementConverter.ts b/tools/polygerrit-updater/src/funcToClassConversion/funcToClassBasedElementConverter.ts
new file mode 100644
index 0000000..b92a6e9
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/funcToClassBasedElementConverter.ts
@@ -0,0 +1,131 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {LegacyLifecycleMethodsArray, LegacyPolymerComponent} from './polymerComponentParser';
+import {LifecycleMethodsBuilder} from './lifecycleMethodsBuilder';
+import {ClassBasedPolymerElement, PolymerElementBuilder} from './polymerElementBuilder';
+import * as codeUtils from '../utils/codeUtils';
+import * as ts from 'typescript';
+
+export class PolymerFuncToClassBasedConverter {
+  public static convert(component: LegacyPolymerComponent): ClassBasedPolymerElement {
+    const legacySettings = component.componentSettings;
+    const reservedDeclarations = legacySettings.reservedDeclarations;
+
+    if(!reservedDeclarations.is) {
+      throw new Error("Legacy component doesn't have 'is' property");
+    }
+    const className = this.generateClassNameFromTagName(reservedDeclarations.is.data);
+    const updater = new PolymerElementBuilder(component, className);
+    updater.addIsAccessor(reservedDeclarations.is.data);
+
+    if(reservedDeclarations.properties) {
+      updater.addPolymerPropertiesAccessor(reservedDeclarations.properties);
+    }
+
+    updater.addMixin("Polymer.Element");
+    updater.addMixin("Polymer.LegacyElementMixin");
+    updater.addMixin("Polymer.GestureEventListeners");
+
+    if(reservedDeclarations._legacyUndefinedCheck) {
+      updater.addMixin("Polymer.LegacyDataMixin");
+    }
+
+    if(reservedDeclarations.behaviors) {
+      updater.addMixin("Polymer.mixinBehaviors", [reservedDeclarations.behaviors.data]);
+      const mixinNames = this.getMixinNamesFromBehaviors(reservedDeclarations.behaviors.data);
+      const jsDocLines = mixinNames.map(mixinName => {
+        return `@appliesMixin ${mixinName}`;
+      });
+      updater.addClassJSDocComments(jsDocLines);
+    }
+
+    if(reservedDeclarations.observers) {
+      updater.addPolymerPropertiesObservers(reservedDeclarations.observers.data);
+    }
+
+    if(reservedDeclarations.keyBindings) {
+      updater.addKeyBindings(reservedDeclarations.keyBindings.data);
+    }
+
+
+    const lifecycleBuilder = new LifecycleMethodsBuilder();
+    if (reservedDeclarations.listeners) {
+      lifecycleBuilder.addListeners(reservedDeclarations.listeners.data, legacySettings.ordinaryMethods);
+    }
+
+    if (reservedDeclarations.hostAttributes) {
+      lifecycleBuilder.addHostAttributes(reservedDeclarations.hostAttributes.data);
+    }
+
+    for(const name of LegacyLifecycleMethodsArray) {
+      const existingMethod = legacySettings.lifecycleMethods.get(name);
+      if(existingMethod) {
+        lifecycleBuilder.addLegacyLifecycleMethod(name, existingMethod)
+      }
+    }
+
+    const newLifecycleMethods = lifecycleBuilder.buildNewMethods();
+    updater.addLifecycleMethods(newLifecycleMethods);
+
+
+    updater.addOrdinaryMethods(legacySettings.ordinaryMethods);
+    updater.addOrdinaryGetAccessors(legacySettings.ordinaryGetAccessors);
+    updater.addOrdinaryShorthandProperties(legacySettings.ordinaryShorthandProperties);
+    updater.addOrdinaryPropertyAssignments(legacySettings.ordinaryPropertyAssignments);
+
+    return updater.build();
+  }
+
+  private static generateClassNameFromTagName(tagName: string) {
+    let result = "";
+    let nextUppercase = true;
+    for(const ch of tagName) {
+      if (ch === '-') {
+        nextUppercase = true;
+        continue;
+      }
+      result += nextUppercase ? ch.toUpperCase() : ch;
+      nextUppercase = false;
+    }
+    return result;
+  }
+
+  private static getMixinNamesFromBehaviors(behaviors: ts.ArrayLiteralExpression): string[] {
+    return behaviors.elements.map((expression) => {
+      const propertyAccessExpression = codeUtils.assertNodeKind(expression, ts.SyntaxKind.PropertyAccessExpression) as ts.PropertyAccessExpression;
+      const namespaceName = codeUtils.assertNodeKind(propertyAccessExpression.expression, ts.SyntaxKind.Identifier) as ts.Identifier;
+      const behaviorName = propertyAccessExpression.name;
+      if(namespaceName.text === 'Gerrit') {
+        let behaviorNameText = behaviorName.text;
+        const suffix = 'Behavior';
+        if(behaviorNameText.endsWith(suffix)) {
+          behaviorNameText =
+              behaviorNameText.substr(0, behaviorNameText.length - suffix.length);
+        }
+        const mixinName = behaviorNameText + 'Mixin';
+        return `${namespaceName.text}.${mixinName}`
+      } else if(namespaceName.text === 'Polymer') {
+        let behaviorNameText = behaviorName.text;
+        if(behaviorNameText === "IronFitBehavior") {
+          return "Polymer.IronFitMixin";
+        } else if(behaviorNameText === "IronOverlayBehavior") {
+          return "";
+        }
+        throw new Error(`Unsupported behavior: ${propertyAccessExpression.getText()}`);
+      }
+      throw new Error(`Unsupported behavior name ${expression.getFullText()}`)
+    }).filter(name => name.length > 0);
+  }
+}
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/legacyPolymerFuncReplacer.ts b/tools/polygerrit-updater/src/funcToClassConversion/legacyPolymerFuncReplacer.ts
new file mode 100644
index 0000000..57b7b8d
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/legacyPolymerFuncReplacer.ts
@@ -0,0 +1,74 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as ts from 'typescript';
+import * as codeUtils from '../utils/codeUtils'
+import {LegacyPolymerComponent} from './polymerComponentParser';
+import {ClassBasedPolymerElement} from './polymerElementBuilder';
+
+export class LegacyPolymerFuncReplaceResult {
+  public constructor(
+      private readonly transformationResult: ts.TransformationResult<ts.SourceFile>,
+      public readonly leadingComments: string[]) {
+  }
+  public get file(): ts.SourceFile {
+    return this.transformationResult.transformed[0];
+  }
+  public dispose() {
+    this.transformationResult.dispose();
+  }
+
+}
+
+export class LegacyPolymerFuncReplacer {
+  private readonly callStatement: ts.ExpressionStatement;
+  private readonly parentBlock: ts.Block;
+  private readonly callStatementIndexInBlock: number;
+  public constructor(private readonly legacyComponent: LegacyPolymerComponent) {
+    this.callStatement = codeUtils.assertNodeKind(legacyComponent.polymerFuncCallExpr.parent, ts.SyntaxKind.ExpressionStatement);
+    this.parentBlock = codeUtils.assertNodeKind(this.callStatement.parent, ts.SyntaxKind.Block);
+    this.callStatementIndexInBlock = this.parentBlock.statements.indexOf(this.callStatement);
+    if(this.callStatementIndexInBlock < 0) {
+      throw new Error("Internal error! Couldn't find statement in its own parent");
+    }
+  }
+  public replace(classBasedElement: ClassBasedPolymerElement): LegacyPolymerFuncReplaceResult {
+    const classDeclarationWithComments = this.appendLeadingCommentToClassDeclaration(classBasedElement.classDeclaration);
+    return new LegacyPolymerFuncReplaceResult(
+        this.replaceLegacyPolymerFunction(classDeclarationWithComments.classDeclarationWithCommentsPlaceholder, classBasedElement.componentRegistration),
+        classDeclarationWithComments.leadingComments);
+  }
+  private appendLeadingCommentToClassDeclaration(classDeclaration: ts.ClassDeclaration): {classDeclarationWithCommentsPlaceholder: ts.ClassDeclaration, leadingComments: string[]} {
+    const text = this.callStatement.getFullText();
+    let classDeclarationWithCommentsPlaceholder = classDeclaration;
+    const leadingComments: string[] = [];
+    ts.forEachLeadingCommentRange(text, 0, (pos, end, kind, hasTrailingNewLine) => {
+      classDeclarationWithCommentsPlaceholder = codeUtils.addReplacableCommentBeforeNode(classDeclarationWithCommentsPlaceholder, String(leadingComments.length));
+      leadingComments.push(text.substring(pos, end));
+    });
+    return {
+      classDeclarationWithCommentsPlaceholder: classDeclarationWithCommentsPlaceholder,
+      leadingComments: leadingComments
+    }
+  }
+  private replaceLegacyPolymerFunction(classDeclaration: ts.ClassDeclaration, componentRegistration: ts.ExpressionStatement): ts.TransformationResult<ts.SourceFile> {
+    const newStatements = Array.from(this.parentBlock.statements);
+    newStatements.splice(this.callStatementIndexInBlock, 1, classDeclaration, componentRegistration);
+
+    const updatedBlock = ts.getMutableClone(this.parentBlock);
+    updatedBlock.statements = ts.createNodeArray(newStatements);
+    return codeUtils.replaceNode(this.legacyComponent.parsedFile, this.parentBlock, updatedBlock);
+
+  }
+}
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/lifecycleMethodsBuilder.ts b/tools/polygerrit-updater/src/funcToClassConversion/lifecycleMethodsBuilder.ts
new file mode 100644
index 0000000..e9e13f5
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/lifecycleMethodsBuilder.ts
@@ -0,0 +1,140 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as ts from 'typescript';
+import * as codeUtils from '../utils/codeUtils';
+import {LegacyLifecycleMethodName, OrdinaryMethods} from './polymerComponentParser';
+
+interface LegacyLifecycleMethodContent {
+  codeAtMethodStart: ts.Statement[];
+  existingMethod?: ts.MethodDeclaration;
+  codeAtMethodEnd: ts.Statement[];
+}
+
+export interface LifecycleMethod {
+  originalPos: number;//-1 - no original method exists
+  method: ts.MethodDeclaration;
+  name: LegacyLifecycleMethodName;
+}
+
+export class LifecycleMethodsBuilder {
+  private readonly methods: Map<LegacyLifecycleMethodName, LegacyLifecycleMethodContent> = new Map();
+
+  private getMethodContent(name: LegacyLifecycleMethodName): LegacyLifecycleMethodContent {
+    if(!this.methods.has(name)) {
+      this.methods.set(name, {
+        codeAtMethodStart: [],
+        codeAtMethodEnd: []
+      });
+    }
+    return this.methods.get(name)!;
+  }
+
+  public addListeners(legacyListeners: ts.ObjectLiteralExpression, legacyOrdinaryMethods: OrdinaryMethods) {
+    for(const listener of legacyListeners.properties) {
+      const propertyAssignment = codeUtils.assertNodeKind(listener, ts.SyntaxKind.PropertyAssignment) as ts.PropertyAssignment;
+      if(!propertyAssignment.name) {
+        throw new Error("Listener must have event name");
+      }
+      let eventNameLiteral: ts.StringLiteral;
+      let commentsToRestore: string[] = [];
+      if(propertyAssignment.name.kind === ts.SyntaxKind.StringLiteral) {
+        //We don't loose comment in this case, because we keep literal as is
+        eventNameLiteral = propertyAssignment.name;
+      } else if(propertyAssignment.name.kind === ts.SyntaxKind.Identifier) {
+        eventNameLiteral = ts.createStringLiteral(propertyAssignment.name.text);
+        commentsToRestore = codeUtils.getLeadingComments(propertyAssignment);
+      } else {
+        throw new Error(`Unsupported type ${ts.SyntaxKind[propertyAssignment.name.kind]}`);
+      }
+
+      const handlerLiteral = codeUtils.assertNodeKind(propertyAssignment.initializer, ts.SyntaxKind.StringLiteral) as ts.StringLiteral;
+      const handlerImpl = legacyOrdinaryMethods.get(handlerLiteral.text);
+      if(!handlerImpl) {
+        throw new Error(`Can't find event handler '${handlerLiteral.text}'`);
+      }
+      const eventHandlerAccess = ts.createPropertyAccess(ts.createThis(), handlerLiteral.text);
+      //ts.forEachChild(handler)
+      const args: ts.Identifier[] = handlerImpl.parameters.map((arg) => codeUtils.assertNodeKind(arg.name, ts.SyntaxKind.Identifier));
+      const eventHandlerCall = ts.createCall(eventHandlerAccess, [], args);
+      let arrowFunc = ts.createArrowFunction([], [], handlerImpl.parameters, undefined, undefined, eventHandlerCall);
+      arrowFunc = codeUtils.addNewLineBeforeNode(arrowFunc);
+
+      const methodContent = this.getMethodContent("created");
+      //See https://polymer-library.polymer-project.org/3.0/docs/devguide/gesture-events for a list of events
+      if(["down", "up", "tap", "track"].indexOf(eventNameLiteral.text) >= 0) {
+        const methodCall = ts.createCall(codeUtils.createNameExpression("Polymer.Gestures.addListener"), [], [ts.createThis(), eventNameLiteral, arrowFunc]);
+        methodContent.codeAtMethodEnd.push(ts.createExpressionStatement(methodCall));
+      }
+      else {
+        let methodCall = ts.createCall(ts.createPropertyAccess(ts.createThis(), "addEventListener"), [], [eventNameLiteral, arrowFunc]);
+        methodCall = codeUtils.restoreLeadingComments(methodCall, commentsToRestore);
+        methodContent.codeAtMethodEnd.push(ts.createExpressionStatement(methodCall));
+      }
+    }
+  }
+
+  public addHostAttributes(legacyHostAttributes: ts.ObjectLiteralExpression) {
+    for(const listener of legacyHostAttributes.properties) {
+      const propertyAssignment = codeUtils.assertNodeKind(listener, ts.SyntaxKind.PropertyAssignment) as ts.PropertyAssignment;
+      if(!propertyAssignment.name) {
+        throw new Error("Listener must have event name");
+      }
+      let attributeNameLiteral: ts.StringLiteral;
+      if(propertyAssignment.name.kind === ts.SyntaxKind.StringLiteral) {
+        attributeNameLiteral = propertyAssignment.name;
+      } else if(propertyAssignment.name.kind === ts.SyntaxKind.Identifier) {
+        attributeNameLiteral = ts.createStringLiteral(propertyAssignment.name.text);
+      } else {
+        throw new Error(`Unsupported type ${ts.SyntaxKind[propertyAssignment.name.kind]}`);
+      }
+      let attributeValueLiteral: ts.StringLiteral | ts.NumericLiteral;
+      if(propertyAssignment.initializer.kind === ts.SyntaxKind.StringLiteral) {
+        attributeValueLiteral = propertyAssignment.initializer as ts.StringLiteral;
+      } else if(propertyAssignment.initializer.kind === ts.SyntaxKind.NumericLiteral) {
+        attributeValueLiteral = propertyAssignment.initializer as ts.NumericLiteral;
+      } else {
+        throw new Error(`Unsupported type ${ts.SyntaxKind[propertyAssignment.initializer.kind]}`);
+      }
+      const methodCall = ts.createCall(ts.createPropertyAccess(ts.createThis(), "_ensureAttribute"), [], [attributeNameLiteral, attributeValueLiteral]);
+      this.getMethodContent("ready").codeAtMethodEnd.push(ts.createExpressionStatement(methodCall));
+    }
+  }
+
+  public addLegacyLifecycleMethod(name: LegacyLifecycleMethodName, method: ts.MethodDeclaration) {
+    const content = this.getMethodContent(name);
+    if(content.existingMethod) {
+      throw new Error(`Legacy lifecycle method ${name} already added`);
+    }
+    content.existingMethod = method;
+  }
+
+  public buildNewMethods(): LifecycleMethod[] {
+    const result = [];
+    for(const [name, content] of this.methods) {
+      const newMethod = this.createLifecycleMethod(name, content.existingMethod, content.codeAtMethodStart, content.codeAtMethodEnd);
+      if(!newMethod) continue;
+      result.push({
+        name,
+        originalPos: content.existingMethod ? content.existingMethod.pos : -1,
+        method: newMethod
+      })
+    }
+    return result;
+  }
+
+  private createLifecycleMethod(name: string, methodDecl: ts.MethodDeclaration | undefined, codeAtStart: ts.Statement[], codeAtEnd: ts.Statement[]): ts.MethodDeclaration | undefined {
+    return codeUtils.createMethod(name, methodDecl, codeAtStart, codeAtEnd, true);
+  }
+}
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/polymerComponentParser.ts b/tools/polygerrit-updater/src/funcToClassConversion/polymerComponentParser.ts
new file mode 100644
index 0000000..6006608
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/polymerComponentParser.ts
@@ -0,0 +1,301 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as ts from "typescript";
+import * as fs from "fs";
+import * as path from "path";
+import { unexpectedValue } from "../utils/unexpectedValue";
+import * as codeUtils from "../utils/codeUtils";
+import {CommentsParser} from '../utils/commentsParser';
+
+export class LegacyPolymerComponentParser {
+  public constructor(private readonly rootDir: string, private readonly htmlFiles: Set<string>) {
+  }
+  public async parse(jsFile: string): Promise<ParsedPolymerComponent | null> {
+    const sourceFile: ts.SourceFile  = this.parseJsFile(jsFile);
+    const legacyComponent = this.tryParseLegacyComponent(sourceFile);
+    if (legacyComponent) {
+      return legacyComponent;
+    }
+    return null;
+  }
+  private parseJsFile(jsFile: string): ts.SourceFile {
+    return ts.createSourceFile(jsFile, fs.readFileSync(path.resolve(this.rootDir, jsFile)).toString(), ts.ScriptTarget.ES2015, true);
+  }
+
+  private tryParseLegacyComponent(sourceFile: ts.SourceFile): ParsedPolymerComponent | null {
+    const polymerFuncCalls: ts.CallExpression[] = [];
+
+    function addPolymerFuncCall(node: ts.Node) {
+      if(node.kind === ts.SyntaxKind.CallExpression) {
+        const callExpression: ts.CallExpression = node as ts.CallExpression;
+        if(callExpression.expression.kind === ts.SyntaxKind.Identifier) {
+          const identifier = callExpression.expression as ts.Identifier;
+          if(identifier.text === "Polymer") {
+            polymerFuncCalls.push(callExpression);
+          }
+        }
+      }
+      ts.forEachChild(node, addPolymerFuncCall);
+    }
+
+    addPolymerFuncCall(sourceFile);
+
+
+    if (polymerFuncCalls.length === 0) {
+      return null;
+    }
+    if (polymerFuncCalls.length > 1) {
+      throw new Error("Each .js file must contain only one Polymer component");
+    }
+    const parsedPath = path.parse(sourceFile.fileName);
+    const htmlFullPath = path.format({
+      dir: parsedPath.dir,
+      name: parsedPath.name,
+      ext: ".html"
+    });
+    if (!this.htmlFiles.has(htmlFullPath)) {
+      throw new Error("Legacy .js component dosn't have associated .html file");
+    }
+
+    const polymerFuncCall = polymerFuncCalls[0];
+    if(polymerFuncCall.arguments.length !== 1) {
+      throw new Error("The Polymer function must be called with exactly one parameter");
+    }
+    const argument = polymerFuncCall.arguments[0];
+    if(argument.kind !== ts.SyntaxKind.ObjectLiteralExpression) {
+      throw new Error("The parameter for Polymer function must be ObjectLiteralExpression (i.e. '{...}')");
+    }
+    const infoArg = argument as ts.ObjectLiteralExpression;
+
+    return {
+      jsFile: sourceFile.fileName,
+      htmlFile: htmlFullPath,
+      parsedFile: sourceFile,
+      polymerFuncCallExpr: polymerFuncCalls[0],
+      componentSettings: this.parseLegacyComponentSettings(infoArg),
+    };
+  }
+
+  private parseLegacyComponentSettings(info: ts.ObjectLiteralExpression): LegacyPolymerComponentSettings {
+    const props: Map<string, ts.ObjectLiteralElementLike> = new Map();
+    for(const property of info.properties) {
+      const name = property.name;
+      if (name === undefined) {
+        throw new Error("Property name is not defined");
+      }
+      switch(name.kind) {
+        case ts.SyntaxKind.Identifier:
+        case ts.SyntaxKind.StringLiteral:
+          if (props.has(name.text)) {
+            throw new Error(`Property ${name.text} appears more than once`);
+          }
+          props.set(name.text, property);
+          break;
+        case ts.SyntaxKind.ComputedPropertyName:
+          continue;
+        default:
+          unexpectedValue(ts.SyntaxKind[name.kind]);
+      }
+    }
+
+    if(props.has("_noAccessors")) {
+      throw new Error("_noAccessors is not supported");
+    }
+
+    const legacyLifecycleMethods: LegacyLifecycleMethods = new Map();
+    for(const name of LegacyLifecycleMethodsArray) {
+      const methodDecl = this.getLegacyMethodDeclaration(props, name);
+      if(methodDecl) {
+        legacyLifecycleMethods.set(name, methodDecl);
+      }
+    }
+
+    const ordinaryMethods: OrdinaryMethods = new Map();
+    const ordinaryShorthandProperties: OrdinaryShorthandProperties = new Map();
+    const ordinaryGetAccessors: OrdinaryGetAccessors = new Map();
+    const ordinaryPropertyAssignments: OrdinaryPropertyAssignments = new Map();
+    for(const [name, val] of props) {
+      if(RESERVED_NAMES.hasOwnProperty(name)) continue;
+      switch(val.kind) {
+        case ts.SyntaxKind.MethodDeclaration:
+          ordinaryMethods.set(name, val as ts.MethodDeclaration);
+          break;
+        case ts.SyntaxKind.ShorthandPropertyAssignment:
+          ordinaryShorthandProperties.set(name, val as ts.ShorthandPropertyAssignment);
+          break;
+        case ts.SyntaxKind.GetAccessor:
+          ordinaryGetAccessors.set(name, val as ts.GetAccessorDeclaration);
+          break;
+        case ts.SyntaxKind.PropertyAssignment:
+          ordinaryPropertyAssignments.set(name, val as ts.PropertyAssignment);
+          break;
+        default:
+          throw new Error(`Unsupported element kind: ${ts.SyntaxKind[val.kind]}`);
+      }
+      //ordinaryMethods.set(name, tsUtils.assertNodeKind(val, ts.SyntaxKind.MethodDeclaration) as ts.MethodDeclaration);
+    }
+
+    const eventsComments: string[] = this.getEventsComments(info.getFullText());
+
+    return {
+      reservedDeclarations: {
+        is: this.getStringLiteralValueWithComments(this.getLegacyPropertyInitializer(props, "is")),
+        _legacyUndefinedCheck: this.getBooleanLiteralValueWithComments(this.getLegacyPropertyInitializer(props, "_legacyUndefinedCheck")),
+        properties: this.getObjectLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "properties")),
+        behaviors: this.getArrayLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "behaviors")),
+        observers: this.getArrayLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "observers")),
+        listeners: this.getObjectLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "listeners")),
+        hostAttributes: this.getObjectLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "hostAttributes")),
+        keyBindings: this.getObjectLiteralExpressionWithComments(this.getLegacyPropertyInitializer(props, "keyBindings")),
+      },
+      eventsComments: eventsComments,
+      lifecycleMethods: legacyLifecycleMethods,
+      ordinaryMethods: ordinaryMethods,
+      ordinaryShorthandProperties: ordinaryShorthandProperties,
+      ordinaryGetAccessors: ordinaryGetAccessors,
+      ordinaryPropertyAssignments: ordinaryPropertyAssignments,
+    };
+  }
+
+  private convertLegacyProeprtyInitializer<T>(initializer: LegacyPropertyInitializer | undefined, converter: (exp: ts.Expression) => T): DataWithComments<T> | undefined {
+    if(!initializer) {
+      return undefined;
+    }
+    return {
+      data: converter(initializer.data),
+      leadingComments: initializer.leadingComments,
+    }
+  }
+
+  private getObjectLiteralExpressionWithComments(initializer: LegacyPropertyInitializer | undefined): DataWithComments<ts.ObjectLiteralExpression> | undefined {
+    return this.convertLegacyProeprtyInitializer(initializer,
+        expr => codeUtils.getObjectLiteralExpression(expr));
+  }
+
+  private getStringLiteralValueWithComments(initializer: LegacyPropertyInitializer | undefined): DataWithComments<string> | undefined {
+    return this.convertLegacyProeprtyInitializer(initializer,
+        expr => codeUtils.getStringLiteralValue(expr));
+  }
+
+  private getBooleanLiteralValueWithComments(initializer: LegacyPropertyInitializer | undefined): DataWithComments<boolean> | undefined {
+    return this.convertLegacyProeprtyInitializer(initializer,
+        expr => codeUtils.getBooleanLiteralValue(expr));
+  }
+
+
+  private getArrayLiteralExpressionWithComments(initializer: LegacyPropertyInitializer | undefined): DataWithComments<ts.ArrayLiteralExpression> | undefined {
+    return this.convertLegacyProeprtyInitializer(initializer,
+        expr => codeUtils.getArrayLiteralExpression(expr));
+  }
+
+  private getLegacyPropertyInitializer(props: Map<String, ts.ObjectLiteralElementLike>, propName: string): LegacyPropertyInitializer | undefined {
+    const property = props.get(propName);
+    if (!property) {
+      return undefined;
+    }
+    const assignment = codeUtils.getPropertyAssignment(property);
+    if (!assignment) {
+      return undefined;
+    }
+    const comments: string[] = codeUtils.getLeadingComments(property)
+          .filter(c => !this.isEventComment(c));
+    return {
+      data: assignment.initializer,
+      leadingComments: comments,
+    };
+  }
+
+  private isEventComment(comment: string): boolean {
+    return comment.indexOf('@event') >= 0;
+  }
+
+  private getEventsComments(polymerComponentSource: string): string[] {
+    return CommentsParser.collectAllComments(polymerComponentSource)
+        .filter(c => this.isEventComment(c));
+  }
+
+  private getLegacyMethodDeclaration(props: Map<String, ts.ObjectLiteralElementLike>, propName: string): ts.MethodDeclaration | undefined {
+    const property = props.get(propName);
+    if (!property) {
+      return undefined;
+    }
+    return codeUtils.assertNodeKind(property, ts.SyntaxKind.MethodDeclaration) as ts.MethodDeclaration;
+  }
+
+}
+
+export type ParsedPolymerComponent = LegacyPolymerComponent;
+
+export interface LegacyPolymerComponent {
+  jsFile: string;
+  htmlFile: string;
+  parsedFile: ts.SourceFile;
+  polymerFuncCallExpr: ts.CallExpression;
+  componentSettings: LegacyPolymerComponentSettings;
+}
+
+export interface LegacyReservedDeclarations {
+  is?: DataWithComments<string>;
+  _legacyUndefinedCheck?: DataWithComments<boolean>;
+  properties?: DataWithComments<ts.ObjectLiteralExpression>;
+  behaviors?: DataWithComments<ts.ArrayLiteralExpression>,
+  observers? :DataWithComments<ts.ArrayLiteralExpression>,
+  listeners? :DataWithComments<ts.ObjectLiteralExpression>,
+  hostAttributes?: DataWithComments<ts.ObjectLiteralExpression>,
+  keyBindings?: DataWithComments<ts.ObjectLiteralExpression>,
+}
+
+export const LegacyLifecycleMethodsArray = <const>["beforeRegister", "registered", "created", "ready", "attached" , "detached", "attributeChanged"];
+export type LegacyLifecycleMethodName = typeof LegacyLifecycleMethodsArray[number];
+export type LegacyLifecycleMethods = Map<LegacyLifecycleMethodName, ts.MethodDeclaration>;
+export type OrdinaryMethods = Map<string, ts.MethodDeclaration>;
+export type OrdinaryShorthandProperties = Map<string, ts.ShorthandPropertyAssignment>;
+export type OrdinaryGetAccessors = Map<string, ts.GetAccessorDeclaration>;
+export type OrdinaryPropertyAssignments = Map<string, ts.PropertyAssignment>;
+export type ReservedName = LegacyLifecycleMethodName | keyof LegacyReservedDeclarations;
+export const RESERVED_NAMES: {[x in ReservedName]: boolean} = {
+  attached: true,
+  detached: true,
+  ready: true,
+  created: true,
+  beforeRegister: true,
+  registered: true,
+  attributeChanged: true,
+  is: true,
+  _legacyUndefinedCheck: true,
+  properties: true,
+  behaviors: true,
+  observers: true,
+  listeners: true,
+  hostAttributes: true,
+  keyBindings: true,
+};
+
+export interface LegacyPolymerComponentSettings {
+  reservedDeclarations: LegacyReservedDeclarations;
+  lifecycleMethods: LegacyLifecycleMethods,
+  ordinaryMethods: OrdinaryMethods,
+  ordinaryShorthandProperties: OrdinaryShorthandProperties,
+  ordinaryGetAccessors: OrdinaryGetAccessors,
+  ordinaryPropertyAssignments: OrdinaryPropertyAssignments,
+  eventsComments: string[];
+}
+
+export interface DataWithComments<T> {
+  data: T;
+  leadingComments: string[];
+}
+
+type LegacyPropertyInitializer = DataWithComments<ts.Expression>;
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/polymerElementBuilder.ts b/tools/polygerrit-updater/src/funcToClassConversion/polymerElementBuilder.ts
new file mode 100644
index 0000000..d6e113c
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/polymerElementBuilder.ts
@@ -0,0 +1,142 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {DataWithComments, LegacyPolymerComponent, LegacyReservedDeclarations, OrdinaryGetAccessors, OrdinaryMethods, OrdinaryPropertyAssignments, OrdinaryShorthandProperties} from './polymerComponentParser';
+import * as ts from 'typescript';
+import * as codeUtils from '../utils/codeUtils';
+import {LifecycleMethod} from './lifecycleMethodsBuilder';
+import {PolymerClassBuilder} from '../utils/polymerClassBuilder';
+import {SyntaxKind} from 'typescript';
+
+export interface ClassBasedPolymerElement {
+  classDeclaration: ts.ClassDeclaration;
+  componentRegistration: ts.ExpressionStatement;
+  eventsComments: string[];
+  generatedComments: string[];
+}
+
+export class PolymerElementBuilder {
+  private readonly reservedDeclarations: LegacyReservedDeclarations;
+  private readonly classBuilder: PolymerClassBuilder;
+  private mixins: ts.ExpressionWithTypeArguments | null;
+
+  public constructor(private readonly legacyComponent: LegacyPolymerComponent, className: string) {
+    this.reservedDeclarations = legacyComponent.componentSettings.reservedDeclarations;
+    this.classBuilder = new PolymerClassBuilder(className);
+    this.mixins = null;
+  }
+
+  public addIsAccessor(tagName: string) {
+    this.classBuilder.addIsAccessor(this.createIsAccessor(tagName));
+  }
+
+  public addPolymerPropertiesAccessor(legacyProperties: DataWithComments<ts.ObjectLiteralExpression>) {
+    const returnStatement = ts.createReturn(legacyProperties.data);
+    const block = ts.createBlock([returnStatement]);
+    let propertiesAccessor = ts.createGetAccessor(undefined, [ts.createModifier(ts.SyntaxKind.StaticKeyword)], "properties", [], undefined, block);
+    if(legacyProperties.leadingComments.length > 0) {
+      propertiesAccessor = codeUtils.restoreLeadingComments(propertiesAccessor, legacyProperties.leadingComments);
+    }
+    this.classBuilder.addPolymerPropertiesAccessor(legacyProperties.data.pos, propertiesAccessor);
+  }
+
+  public addPolymerPropertiesObservers(legacyObservers: ts.ArrayLiteralExpression) {
+    const returnStatement = ts.createReturn(legacyObservers);
+    const block = ts.createBlock([returnStatement]);
+    const propertiesAccessor = ts.createGetAccessor(undefined, [ts.createModifier(ts.SyntaxKind.StaticKeyword)], "observers", [], undefined, block);
+
+    this.classBuilder.addPolymerObserversAccessor(legacyObservers.pos, propertiesAccessor);
+  }
+
+  public addKeyBindings(keyBindings: ts.ObjectLiteralExpression) {
+    //In Polymer 2 keyBindings must be a property with get accessor
+    const returnStatement = ts.createReturn(keyBindings);
+    const block = ts.createBlock([returnStatement]);
+    const keyBindingsAccessor = ts.createGetAccessor(undefined, [], "keyBindings", [], undefined, block);
+
+    this.classBuilder.addGetAccessor(keyBindings.pos, keyBindingsAccessor);
+  }
+  public addOrdinaryMethods(ordinaryMethods: OrdinaryMethods) {
+    for(const [name, method] of ordinaryMethods) {
+      this.classBuilder.addMethod(method.pos, method);
+    }
+  }
+
+  public addOrdinaryGetAccessors(ordinaryGetAccessors: OrdinaryGetAccessors) {
+    for(const [name, accessor] of ordinaryGetAccessors) {
+      this.classBuilder.addGetAccessor(accessor.pos, accessor);
+    }
+  }
+
+  public addOrdinaryShorthandProperties(ordinaryShorthandProperties: OrdinaryShorthandProperties) {
+    for (const [name, property] of ordinaryShorthandProperties) {
+      this.classBuilder.addClassFieldInitializer(property.name, property.name);
+    }
+  }
+
+  public addOrdinaryPropertyAssignments(ordinaryPropertyAssignments: OrdinaryPropertyAssignments) {
+    for (const [name, property] of ordinaryPropertyAssignments) {
+      const propertyName = codeUtils.assertNodeKind(property.name, ts.SyntaxKind.Identifier) as ts.Identifier;
+      this.classBuilder.addClassFieldInitializer(propertyName, property.initializer);
+    }
+  }
+
+  public addMixin(name: string, mixinArguments?: ts.Expression[]) {
+    let fullMixinArguments: ts.Expression[] = [];
+    if(mixinArguments) {
+      fullMixinArguments.push(...mixinArguments);
+    }
+    if(this.mixins) {
+      fullMixinArguments.push(this.mixins.expression);
+    }
+    if(fullMixinArguments.length > 0) {
+      this.mixins = ts.createExpressionWithTypeArguments([], ts.createCall(codeUtils.createNameExpression(name), [], fullMixinArguments.length > 0 ? fullMixinArguments : undefined));
+    }
+    else {
+      this.mixins = ts.createExpressionWithTypeArguments([], codeUtils.createNameExpression(name));
+    }
+  }
+
+  public addClassJSDocComments(lines: string[]) {
+    this.classBuilder.addClassJSDocComments(lines);
+  }
+
+  public build(): ClassBasedPolymerElement {
+    if(this.mixins) {
+      this.classBuilder.setBaseType(this.mixins);
+    }
+    const className = this.classBuilder.className;
+    const callExpression = ts.createCall(ts.createPropertyAccess(ts.createIdentifier("customElements"), "define"), undefined, [ts.createPropertyAccess(ts.createIdentifier(className), "is"), ts.createIdentifier(className)]);
+    const classBuilderResult = this.classBuilder.build();
+    return {
+      classDeclaration: classBuilderResult.classDeclaration,
+      generatedComments: classBuilderResult.generatedComments,
+      componentRegistration: ts.createExpressionStatement(callExpression),
+      eventsComments: this.legacyComponent.componentSettings.eventsComments,
+    };
+  }
+
+  private createIsAccessor(tagName: string): ts.GetAccessorDeclaration {
+    const returnStatement = ts.createReturn(ts.createStringLiteral(tagName));
+    const block = ts.createBlock([returnStatement]);
+    const accessor = ts.createGetAccessor([], [ts.createModifier(ts.SyntaxKind.StaticKeyword)], "is", [], undefined, block);
+    return codeUtils.addReplacableCommentAfterNode(accessor, "eventsComments");
+  }
+
+  public addLifecycleMethods(newLifecycleMethods: LifecycleMethod[]) {
+    for(const lifecycleMethod of newLifecycleMethods) {
+      this.classBuilder.addLifecycleMethod(lifecycleMethod.name, lifecycleMethod.originalPos, lifecycleMethod.method);
+    }
+  }
+}
diff --git a/tools/polygerrit-updater/src/funcToClassConversion/updatedFileWriter.ts b/tools/polygerrit-updater/src/funcToClassConversion/updatedFileWriter.ts
new file mode 100644
index 0000000..a147f50
--- /dev/null
+++ b/tools/polygerrit-updater/src/funcToClassConversion/updatedFileWriter.ts
@@ -0,0 +1,248 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {LegacyPolymerComponent} from './polymerComponentParser';
+import * as ts from 'typescript';
+import * as codeUtils from '../utils/codeUtils';
+import * as path from "path";
+import * as fs from "fs";
+import {LegacyPolymerFuncReplaceResult} from './legacyPolymerFuncReplacer';
+import {CommentsParser} from '../utils/commentsParser';
+
+export interface UpdatedFileWriterParameters {
+  out: string;
+  inplace: boolean;
+  writeOutput: boolean;
+  rootDir: string;
+}
+
+interface Replacement {
+  start: number;
+  length: number;
+  newText: string;
+}
+
+const elementRegistrationRegex = /^(\s*)customElements.define\((\w+).is, \w+\);$/m;
+const maxLineLength = 80;
+
+export class UpdatedFileWriter {
+  public constructor(private readonly component: LegacyPolymerComponent, private readonly params: UpdatedFileWriterParameters) {
+  }
+
+  public write(replaceResult: LegacyPolymerFuncReplaceResult, eventsComments: string[], generatedComments: string[]) {
+    const options: ts.PrinterOptions = {
+      removeComments: false,
+      newLine: ts.NewLineKind.LineFeed,
+    };
+    const printer = ts.createPrinter(options);
+    let newContent = codeUtils.applyNewLines(printer.printFile(replaceResult.file));
+    //ts printer doesn't keep original formatting of the file (spacing, new lines, comments, etc...).
+    //The following code tries restore original formatting
+
+    const existingComments = this.collectAllComments(newContent, []);
+
+    newContent = this.restoreEventsComments(newContent, eventsComments, existingComments);
+    newContent = this.restoreLeadingComments(newContent, replaceResult.leadingComments);
+    newContent = this.restoreFormating(printer, newContent);
+    newContent = this.splitLongLines(newContent);
+    newContent = this.addCommentsWarnings(newContent, generatedComments);
+
+    if (this.params.writeOutput) {
+      const outDir = this.params.inplace ? this.params.rootDir : this.params.out;
+      const fullOutPath = path.resolve(outDir, this.component.jsFile);
+      const fullOutDir = path.dirname(fullOutPath);
+      if (!fs.existsSync(fullOutDir)) {
+        fs.mkdirSync(fullOutDir, {
+          recursive: true,
+          mode: fs.lstatSync(this.params.rootDir).mode
+        });
+      }
+      fs.writeFileSync(fullOutPath, newContent);
+    }
+  }
+
+  private restoreEventsComments(content: string, eventsComments: string[], existingComments: Map<string, number>): string {
+    //In some cases Typescript compiler keep existing comments. These comments
+    // must not be restored here
+    eventsComments = eventsComments.filter(c => !existingComments.has(this.getNormalizedComment(c)));
+    return codeUtils.replaceComment(content, "eventsComments", "\n" + eventsComments.join("\n\n") + "\n");
+  }
+
+  private restoreLeadingComments(content: string, leadingComments: string[]): string {
+    return leadingComments.reduce(
+        (newContent, comment, commentIndex) =>
+            codeUtils.replaceComment(newContent, String(commentIndex), comment),
+        content);
+  }
+
+  private restoreFormating(printer: ts.Printer, newContent: string): string {
+    const originalFile = this.component.parsedFile;
+    const newFile = ts.createSourceFile(originalFile.fileName, newContent, originalFile.languageVersion, true, ts.ScriptKind.JS);
+    const textMap = new Map<ts.SyntaxKind, Map<string, Set<string>>>();
+    const comments = new Set<string>();
+    this.collectAllStrings(printer, originalFile, textMap);
+
+    const replacements: Replacement[] = [];
+    this.collectReplacements(printer, newFile, textMap, replacements);
+    replacements.sort((a, b) => b.start - a.start);
+    let result = newFile.getFullText();
+    let prevReplacement: Replacement | null = null;
+    for (const replacement of replacements) {
+      if (prevReplacement) {
+        if (replacement.start + replacement.length > prevReplacement.start) {
+          throw new Error('Internal error! Replacements must not intersect');
+        }
+      }
+      result = result.substring(0, replacement.start) + replacement.newText + result.substring(replacement.start + replacement.length);
+      prevReplacement = replacement;
+    }
+    return result;
+  }
+
+  private splitLongLines(content: string): string {
+    content = content.replace(elementRegistrationRegex, (match, indent, className) => {
+      if (match.length > maxLineLength) {
+        return `${indent}customElements.define(${className}.is,\n` +
+            `${indent}  ${className});`;
+      }
+      else {
+        return match;
+      }
+    });
+
+    return content
+        .replace(
+            "Polymer.LegacyDataMixin(Polymer.GestureEventListeners(Polymer.LegacyElementMixin(Polymer.Element)))",
+            "Polymer.LegacyDataMixin(\nPolymer.GestureEventListeners(\nPolymer.LegacyElementMixin(\nPolymer.Element)))")
+        .replace(
+            "Polymer.GestureEventListeners(Polymer.LegacyElementMixin(Polymer.Element))",
+            "Polymer.GestureEventListeners(\nPolymer.LegacyElementMixin(\nPolymer.Element))");
+
+  }
+
+  private addCommentsWarnings(newContent: string, generatedComments: string[]): string {
+    const expectedComments = this.collectAllComments(this.component.parsedFile.getFullText(), generatedComments);
+    const newComments = this.collectAllComments(newContent, []);
+    const commentsWarnings = [];
+    for (const [text, count] of expectedComments) {
+      const newCount = newComments.get(text);
+      if (!newCount) {
+        commentsWarnings.push(`Comment '${text}' is missing in the new content.`);
+      }
+      else if (newCount != count) {
+        commentsWarnings.push(`Comment '${text}' appears ${newCount} times in the new file and ${count} times in the old file.`);
+      }
+    }
+
+    for (const [text, newCount] of newComments) {
+      if (!expectedComments.has(text)) {
+        commentsWarnings.push(`Comment '${text}' appears only in the new content`);
+      }
+    }
+    if (commentsWarnings.length === 0) {
+      return newContent;
+    }
+    let commentsProblemStr = "";
+    if (commentsWarnings.length > 0) {
+      commentsProblemStr = commentsWarnings.join("-----------------------------\n");
+      console.log(commentsProblemStr);
+    }
+
+    return "//This file has the following problems with comments:\n" + commentsProblemStr + "\n" + newContent;
+
+  }
+
+  private collectAllComments(content: string, additionalComments: string[]): Map<string, number> {
+    const comments = CommentsParser.collectAllComments(content);
+    comments.push(...additionalComments);
+    const result = new Map<string, number>();
+    for (const comment of comments) {
+      let normalizedComment = this.getNormalizedComment(comment);
+      const count = result.get(normalizedComment);
+      if (count) {
+        result.set(normalizedComment, count + 1);
+      } else {
+        result.set(normalizedComment, 1);
+      }
+    }
+    return result;
+  }
+
+  private getNormalizedComment(comment: string): string {
+    if(comment.startsWith('/**')) {
+      comment = comment.replace(/^\s+\*/gm, "*");
+    }
+    return comment;
+  }
+
+  private collectAllStrings(printer: ts.Printer, node: ts.Node, map: Map<ts.SyntaxKind, Map<string, Set<string>>>) {
+    const formattedText = printer.printNode(ts.EmitHint.Unspecified, node, node.getSourceFile())
+    const originalText = node.getFullText();
+    this.addIfNotExists(map, node.kind, formattedText, originalText);
+    ts.forEachChild(node, child => this.collectAllStrings(printer, child, map));
+  }
+
+  private collectReplacements(printer: ts.Printer, node: ts.Node, map: Map<ts.SyntaxKind, Map<string, Set<string>>>, replacements: Replacement[]) {
+    if(node.kind === ts.SyntaxKind.ThisKeyword || node.kind === ts.SyntaxKind.Identifier || node.kind === ts.SyntaxKind.StringLiteral || node.kind === ts.SyntaxKind.NumericLiteral) {
+      return;
+    }
+    const replacement = this.getReplacement(printer, node, map);
+    if(replacement) {
+      replacements.push(replacement);
+      return;
+    }
+    ts.forEachChild(node, child => this.collectReplacements(printer, child, map, replacements));
+  }
+
+  private addIfNotExists(map: Map<ts.SyntaxKind, Map<string, Set<string>>>, kind: ts.SyntaxKind, formattedText: string, originalText: string) {
+    let mapForKind = map.get(kind);
+    if(!mapForKind) {
+      mapForKind = new Map();
+      map.set(kind, mapForKind);
+    }
+
+    let existingOriginalText = mapForKind.get(formattedText);
+    if(!existingOriginalText) {
+      existingOriginalText = new Set<string>();
+      mapForKind.set(formattedText, existingOriginalText);
+      //throw new Error(`Different formatting of the same string exists. Kind: ${ts.SyntaxKind[kind]}.\nFormatting 1:\n${originalText}\nFormatting2:\n${existingOriginalText}\n `);
+    }
+    existingOriginalText.add(originalText);
+  }
+
+  private getReplacement(printer: ts.Printer, node: ts.Node, map: Map<ts.SyntaxKind, Map<string, Set<string>>>): Replacement | undefined {
+    const replacementsForKind = map.get(node.kind);
+    if(!replacementsForKind) {
+      return;
+    }
+    // Use printer instead of getFullText to "isolate" node content.
+    // node.getFullText returns text with indents from the original file.
+    const newText = printer.printNode(ts.EmitHint.Unspecified, node, node.getSourceFile());
+    const originalSet = replacementsForKind.get(newText);
+    if(!originalSet || originalSet.size === 0) {
+      return;
+    }
+    if(originalSet.size >= 2) {
+      console.log(`Multiple replacements possible. Formatting of some lines can be changed`);
+    }
+    const replacementText: string = originalSet.values().next().value;
+    const nodeText = node.getFullText();
+    return {
+      start: node.pos,
+      length: nodeText.length,//Do not use newText here!
+      newText: replacementText,
+    }
+  }
+
+}
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/index.ts b/tools/polygerrit-updater/src/index.ts
new file mode 100644
index 0000000..1b7c315
--- /dev/null
+++ b/tools/polygerrit-updater/src/index.ts
@@ -0,0 +1,168 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as fs from "fs";
+import * as path from "path";
+import {LegacyPolymerComponent, LegacyPolymerComponentParser} from './funcToClassConversion/polymerComponentParser';
+import {ClassBasedPolymerElement} from './funcToClassConversion/polymerElementBuilder';
+import {PolymerFuncToClassBasedConverter} from './funcToClassConversion/funcToClassBasedElementConverter';
+import {LegacyPolymerFuncReplacer} from './funcToClassConversion/legacyPolymerFuncReplacer';
+import {UpdatedFileWriter} from './funcToClassConversion/updatedFileWriter';
+import {CommandLineParser} from './utils/commandLineParser';
+
+interface UpdaterParameters {
+  htmlFiles: Set<string>;
+  jsFiles: Set<string>;
+  out: string;
+  inplace: boolean;
+  writeOutput: boolean;
+  rootDir: string;
+}
+
+interface InputFilesFilter {
+  includeDir(path: string): boolean;
+  includeFile(path: string): boolean;
+}
+
+function addFile(filePath: string, params: UpdaterParameters, filter: InputFilesFilter) {
+  const parsedPath = path.parse(filePath);
+  const ext = parsedPath.ext.toLowerCase();
+  const relativePath = path.relative(params.rootDir, filePath);
+  if(!filter.includeFile(relativePath)) return;
+  if(relativePath.startsWith("../")) {
+    throw new Error(`${filePath} is not in rootDir ${params.rootDir}`);
+  }
+  if(ext === ".html") {
+    params.htmlFiles.add(relativePath);
+  } if(ext === ".js") {
+    params.jsFiles.add(relativePath);
+  }
+}
+
+function addDirectory(dirPath: string, params: UpdaterParameters, recursive: boolean, filter: InputFilesFilter): void {
+  const entries = fs.readdirSync(dirPath, {withFileTypes: true});
+  for(const entry of entries) {
+    const dirEnt = entry as fs.Dirent;
+    const fullPath = path.join(dirPath, dirEnt.name);
+    const relativePath = path.relative(params.rootDir, fullPath);
+    if(dirEnt.isDirectory()) {
+      if (!filter.includeDir(relativePath)) continue;
+      if(recursive) {
+        addDirectory(fullPath, params, recursive, filter);
+      }
+    }
+    else if(dirEnt.isFile()) {
+      addFile(fullPath, params, filter);
+    } else {
+      throw Error(`Unsupported dir entry '${entry.name}' in '${fullPath}'`);
+    }
+  }
+}
+
+async function updateLegacyComponent(component: LegacyPolymerComponent, params: UpdaterParameters) {
+  const classBasedElement: ClassBasedPolymerElement = PolymerFuncToClassBasedConverter.convert(component);
+
+  const replacer = new LegacyPolymerFuncReplacer(component);
+  const replaceResult = replacer.replace(classBasedElement);
+  try {
+    const writer = new UpdatedFileWriter(component, params);
+    writer.write(replaceResult, classBasedElement.eventsComments, classBasedElement.generatedComments);
+  }
+  finally {
+    replaceResult.dispose();
+  }
+}
+
+async function main() {
+  const params: UpdaterParameters = await getParams();
+  if(params.jsFiles.size === 0) {
+    console.log("No files found");
+    return;
+  }
+  const legacyPolymerComponentParser = new LegacyPolymerComponentParser(params.rootDir, params.htmlFiles)
+  for(const jsFile of params.jsFiles) {
+    console.log(`Processing ${jsFile}`);
+    const legacyComponent = await legacyPolymerComponentParser.parse(jsFile);
+    if(legacyComponent) {
+      await updateLegacyComponent(legacyComponent, params);
+      continue;
+    }
+  }
+}
+
+interface CommandLineParameters {
+  src: string[];
+  recursive: boolean;
+  excludes: string[];
+  out: string;
+  inplace: boolean;
+  noOutput: boolean;
+  rootDir: string;
+}
+
+async function getParams(): Promise<UpdaterParameters> {
+  const parser = new CommandLineParser({
+    src: CommandLineParser.createStringArrayOption("src", ".js file or folder to process", []),
+    recursive: CommandLineParser.createBooleanOption("r", "process folder recursive", false),
+    excludes: CommandLineParser.createStringArrayOption("exclude", "List of file prefixes to exclude. If relative file path starts with one of the prefixes, it will be excluded", []),
+    out: CommandLineParser.createStringOption("out", "Output folder.", null),
+    rootDir: CommandLineParser.createStringOption("root", "Root directory for src files", "/"),
+    inplace: CommandLineParser.createBooleanOption("i", "Update files inplace", false),
+    noOutput: CommandLineParser.createBooleanOption("noout", "Do everything, but do not write anything to files", false),
+  });
+  const commandLineParams: CommandLineParameters = parser.parse(process.argv) as CommandLineParameters;
+
+  const params: UpdaterParameters = {
+    htmlFiles: new Set(),
+    jsFiles: new Set(),
+    writeOutput: !commandLineParams.noOutput,
+    inplace: commandLineParams.inplace,
+    out: commandLineParams.out,
+    rootDir: path.resolve(commandLineParams.rootDir)
+  };
+
+  if(params.writeOutput && !params.inplace && !params.out) {
+    throw new Error("You should specify output directory (--out directory_name)");
+  }
+
+  const filter = new ExcludeFilesFilter(commandLineParams.excludes);
+  for(const srcPath of commandLineParams.src) {
+    const resolvedPath = path.resolve(params.rootDir, srcPath);
+    if(fs.lstatSync(resolvedPath).isFile()) {
+      addFile(resolvedPath, params, filter);
+    } else {
+      addDirectory(resolvedPath, params, commandLineParams.recursive, filter);
+    }
+  }
+  return params;
+}
+
+class ExcludeFilesFilter implements InputFilesFilter {
+  public constructor(private readonly excludes: string[]) {
+  }
+  includeDir(path: string): boolean {
+    return this.excludes.every(exclude => !path.startsWith(exclude));
+  }
+
+  includeFile(path: string): boolean {
+    return this.excludes.every(exclude => !path.startsWith(exclude));
+  }
+}
+
+main().then(() => {
+  process.exit(0);
+}).catch(e => {
+  console.error(e);
+  process.exit(1);
+});
diff --git a/tools/polygerrit-updater/src/utils/codeUtils.ts b/tools/polygerrit-updater/src/utils/codeUtils.ts
new file mode 100644
index 0000000..53a7f0d
--- /dev/null
+++ b/tools/polygerrit-updater/src/utils/codeUtils.ts
@@ -0,0 +1,183 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as ts from 'typescript';
+import {SyntaxKind} from 'typescript';
+import {Node} from 'typescript';
+
+export function assertNodeKind<T extends U, U extends ts.Node>(node: U, expectedKind: ts.SyntaxKind): T {
+  if (node.kind !== expectedKind) {
+    throw new Error(`Invlid node kind. Expected: ${ts.SyntaxKind[expectedKind]}, actual: ${ts.SyntaxKind[node.kind]}`);
+  }
+  return node as T;
+}
+
+export function assertNodeKindOrUndefined<T extends U, U extends ts.Node>(node: U | undefined, expectedKind: ts.SyntaxKind): T | undefined {
+  if (!node) {
+    return undefined;
+  }
+  return assertNodeKind<T, U>(node, expectedKind);
+}
+
+export function getPropertyAssignment(expression?: ts.ObjectLiteralElementLike): ts.PropertyAssignment | undefined {
+  return assertNodeKindOrUndefined(expression, ts.SyntaxKind.PropertyAssignment);
+}
+
+export function getStringLiteralValue(expression: ts.Expression): string {
+  const literal: ts.StringLiteral = assertNodeKind(expression, ts.SyntaxKind.StringLiteral);
+  return literal.text;
+}
+
+export function getBooleanLiteralValue(expression: ts.Expression): boolean {
+  if (expression.kind === ts.SyntaxKind.TrueKeyword) {
+    return true;
+  }
+  if (expression.kind === ts.SyntaxKind.FalseKeyword) {
+    return false;
+  }
+  throw new Error(`Invalid expression kind - ${expression.kind}`);
+}
+
+export function getObjectLiteralExpression(expression: ts.Expression): ts.ObjectLiteralExpression {
+  return assertNodeKind(expression, ts.SyntaxKind.ObjectLiteralExpression);
+}
+
+export function getArrayLiteralExpression(expression: ts.Expression): ts.ArrayLiteralExpression {
+  return assertNodeKind(expression, ts.SyntaxKind.ArrayLiteralExpression);
+}
+
+export function replaceNode(file: ts.SourceFile, originalNode: ts.Node, newNode: ts.Node): ts.TransformationResult<ts.SourceFile> {
+  const nodeReplacerTransformer: ts.TransformerFactory<ts.SourceFile> = (context: ts.TransformationContext) => {
+    const visitor: ts.Visitor = (node) => {
+      if(node === originalNode) {
+        return newNode;
+      }
+      return ts.visitEachChild(node, visitor, context);
+    };
+
+
+    return source => ts.visitNode(source, visitor);
+  };
+  return ts.transform(file, [nodeReplacerTransformer]);
+}
+
+export type NameExpression = ts.Identifier | ts.ThisExpression | ts.PropertyAccessExpression;
+export function createNameExpression(fullPath: string): NameExpression {
+  const parts = fullPath.split(".");
+  let result: NameExpression = parts[0] === "this" ? ts.createThis() : ts.createIdentifier(parts[0]);
+  for(let i = 1; i < parts.length; i++) {
+    result = ts.createPropertyAccess(result, parts[i]);
+  }
+  return result;
+}
+
+const generatedCommentNewLineAfterText = "-Generated code - new line after - 9cb292bc-5d88-4c5e-88f4-49535c93beb9 -";
+const generatedCommentNewLineBeforeText = "-Generated code - new line-before - 9cb292bc-5d88-4c5e-88f4-49535c93beb9 -";
+const generatedCommentNewLineAfterRegExp = new RegExp("//" + generatedCommentNewLineAfterText, 'g');
+const generatedCommentNewLineBeforeRegExp = new RegExp("//" + generatedCommentNewLineBeforeText + "\n", 'g');
+const replacableCommentText = "- Replacepoint - 9cb292bc-5d88-4c5e-88f4-49535c93beb9 -";
+
+export function addNewLineAfterNode<T extends ts.Node>(node: T): T {
+  const comment = ts.getSyntheticTrailingComments(node);
+  if(comment && comment.some(c => c.text === generatedCommentNewLineAfterText)) {
+    return node;
+  }
+  return ts.addSyntheticTrailingComment(node, ts.SyntaxKind.SingleLineCommentTrivia, generatedCommentNewLineAfterText, true);
+}
+
+export function addNewLineBeforeNode<T extends ts.Node>(node: T): T {
+  const comment = ts.getSyntheticLeadingComments(node);
+  if(comment && comment.some(c => c.text === generatedCommentNewLineBeforeText)) {
+    return node;
+  }
+  return ts.addSyntheticLeadingComment(node, ts.SyntaxKind.SingleLineCommentTrivia, generatedCommentNewLineBeforeText, true);
+}
+
+
+export function applyNewLines(text: string): string {
+  return text.replace(generatedCommentNewLineAfterRegExp, "").replace(generatedCommentNewLineBeforeRegExp, "");
+
+}
+export function addReplacableCommentAfterNode<T extends ts.Node>(node: T, name: string): T {
+  return ts.addSyntheticTrailingComment(node, ts.SyntaxKind.SingleLineCommentTrivia, replacableCommentText + name, true);
+}
+
+export function addReplacableCommentBeforeNode<T extends ts.Node>(node: T, name: string): T {
+  return ts.addSyntheticLeadingComment(node, ts.SyntaxKind.SingleLineCommentTrivia, replacableCommentText + name, true);
+}
+
+export function replaceComment(text: string, commentName: string, newContent: string): string {
+  return text.replace("//" + replacableCommentText + commentName, newContent);
+}
+
+export function createMethod(name: string, methodDecl: ts.MethodDeclaration | undefined, codeAtStart: ts.Statement[], codeAtEnd: ts.Statement[], callSuperMethod: boolean): ts.MethodDeclaration | undefined {
+  if(!methodDecl && (codeAtEnd.length > 0 || codeAtEnd.length > 0)) {
+    methodDecl = ts.createMethod([], [], undefined, name, undefined, [], [],undefined, ts.createBlock([]));
+  }
+  if(!methodDecl) {
+    return;
+  }
+  if (!methodDecl.body) {
+    throw new Error("Method must have a body");
+  }
+  if(methodDecl.parameters.length > 0) {
+    throw new Error("Methods with parameters are not supported");
+  }
+  let newStatements = [...codeAtStart];
+  if(callSuperMethod) {
+    const superCall: ts.CallExpression = ts.createCall(ts.createPropertyAccess(ts.createSuper(), assertNodeKind(methodDecl.name, ts.SyntaxKind.Identifier) as ts.Identifier), [], []);
+    const superCallExpression = ts.createExpressionStatement(superCall);
+    newStatements.push(superCallExpression);
+  }
+  newStatements.push(...codeAtEnd);
+  const newBody = ts.getMutableClone(methodDecl.body);
+
+  newStatements = newStatements.map(m => addNewLineAfterNode(m));
+  newStatements.splice(codeAtStart.length + 1, 0, ...newBody.statements);
+
+  newBody.statements = ts.createNodeArray(newStatements);
+
+  const newMethod = ts.getMutableClone(methodDecl);
+  newMethod.body = newBody;
+
+  return newMethod;
+}
+
+export function restoreLeadingComments<T extends Node>(node: T, originalComments: string[]): T {
+  if(originalComments.length === 0) {
+    return node;
+  }
+  for(const comment of originalComments) {
+    if(comment.startsWith("//")) {
+      node = ts.addSyntheticLeadingComment(node, SyntaxKind.SingleLineCommentTrivia, comment.substr(2), true);
+    } else if(comment.startsWith("/*")) {
+      if(!comment.endsWith("*/")) {
+        throw new Error(`Not support comment: ${comment}`);
+      }
+      node = ts.addSyntheticLeadingComment(node, SyntaxKind.MultiLineCommentTrivia, comment.substr(2, comment.length - 4), true);
+    } else {
+      throw new Error(`Not supported comment: ${comment}`);
+    }
+  }
+  return node;
+}
+
+export function getLeadingComments(node: ts.Node): string[] {
+  const nodeText = node.getFullText();
+  const commentRanges = ts.getLeadingCommentRanges(nodeText, 0);
+  if(!commentRanges) {
+    return [];
+  }
+  return commentRanges.map(range => nodeText.substring(range.pos, range.end))
+}
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/utils/commandLineParser.ts b/tools/polygerrit-updater/src/utils/commandLineParser.ts
new file mode 100644
index 0000000..658b7ff
--- /dev/null
+++ b/tools/polygerrit-updater/src/utils/commandLineParser.ts
@@ -0,0 +1,134 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed un  der the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+export class CommandLineParser {
+  public static createStringArrayOption(optionName: string, help: string, defaultValue: string[]): CommandLineArgument {
+    return new StringArrayOption(optionName, help, defaultValue);
+  }
+  public static createBooleanOption(optionName: string, help: string, defaultValue: boolean): CommandLineArgument {
+    return new BooleanOption(optionName, help, defaultValue);
+  }
+  public static createStringOption(optionName: string, help: string, defaultValue: string | null): CommandLineArgument {
+    return new StringOption(optionName, help, defaultValue);
+  }
+
+  public constructor(private readonly argumentTypes: {[name: string]: CommandLineArgument}) {
+  }
+  public parse(argv: string[]): object {
+    const result = Object.assign({});
+    let index = 2; //argv[0] - node interpreter, argv[1] - index.js
+    for(const argumentField in this.argumentTypes) {
+      result[argumentField] = this.argumentTypes[argumentField].getDefaultValue();
+    }
+    while(index < argv.length) {
+      let knownArgument = false;
+      for(const argumentField in this.argumentTypes) {
+        const argumentType = this.argumentTypes[argumentField];
+        const argumentValue = argumentType.tryRead(argv, index);
+        if(argumentValue) {
+          knownArgument = true;
+          index += argumentValue.consumed;
+          result[argumentField] = argumentValue.value;
+          break;
+        }
+      }
+      if(!knownArgument) {
+        throw new Error(`Unknown argument ${argv[index]}`);
+      }
+    }
+    return result;
+  }
+}
+
+interface CommandLineArgumentReadResult {
+  consumed: number;
+  value: any;
+}
+
+export interface CommandLineArgument {
+  getDefaultValue(): any;
+  tryRead(argv: string[], startIndex: number): CommandLineArgumentReadResult | null;
+}
+
+abstract class CommandLineOption implements CommandLineArgument {
+  protected constructor(protected readonly optionName: string, protected readonly help: string, private readonly defaultValue: any) {
+  }
+  public tryRead(argv: string[], startIndex: number): CommandLineArgumentReadResult | null  {
+    if(argv[startIndex] !== "--" + this.optionName) {
+      return null;
+    }
+    const readArgumentsResult = this.readArguments(argv, startIndex + 1);
+    if(!readArgumentsResult) {
+      return null;
+    }
+    readArgumentsResult.consumed++; // Add option name
+    return readArgumentsResult;
+  }
+  public getDefaultValue(): any {
+    return this.defaultValue;
+  }
+
+  protected abstract readArguments(argv: string[], startIndex: number) : CommandLineArgumentReadResult | null;
+}
+
+class StringArrayOption extends CommandLineOption {
+  public constructor(optionName: string, help: string, defaultValue: string[]) {
+    super(optionName, help, defaultValue);
+  }
+
+  protected readArguments(argv: string[], startIndex: number): CommandLineArgumentReadResult {
+    const result = [];
+    let index = startIndex;
+    while(index < argv.length) {
+      if(argv[index].startsWith("--")) {
+        break;
+      }
+      result.push(argv[index]);
+      index++;
+    }
+    return {
+      consumed: index - startIndex,
+      value: result
+    }
+  }
+}
+
+class BooleanOption extends CommandLineOption {
+  public constructor(optionName: string, help: string, defaultValue: boolean) {
+    super(optionName, help, defaultValue);
+  }
+
+  protected readArguments(argv: string[], startIndex: number): CommandLineArgumentReadResult {
+    return {
+      consumed: 0,
+      value: true
+    }
+  }
+}
+
+class StringOption extends CommandLineOption {
+  public constructor(optionName: string, help: string, defaultValue: string | null) {
+    super(optionName, help, defaultValue);
+  }
+
+  protected readArguments(argv: string[], startIndex: number): CommandLineArgumentReadResult | null {
+    if(startIndex >= argv.length) {
+      return null;
+    }
+    return {
+      consumed: 1,
+      value: argv[startIndex]
+    }
+  }
+}
diff --git a/tools/polygerrit-updater/src/utils/commentsParser.ts b/tools/polygerrit-updater/src/utils/commentsParser.ts
new file mode 100644
index 0000000..b849829
--- /dev/null
+++ b/tools/polygerrit-updater/src/utils/commentsParser.ts
@@ -0,0 +1,79 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+enum CommentScannerState {
+  Text,
+  SingleLineComment,
+  MultLineComment
+}
+export class CommentsParser {
+  public static collectAllComments(text: string): string[] {
+    const result: string[] = [];
+    let state = CommentScannerState.Text;
+    let pos = 0;
+    function readSingleLineComment() {
+      const startPos = pos;
+      while(pos < text.length && text[pos] !== '\n') {
+        pos++;
+      }
+      return text.substring(startPos, pos);
+    }
+    function readMultiLineComment() {
+      const startPos = pos;
+      while(pos < text.length) {
+        if(pos < text.length - 1 && text[pos] === '*' && text[pos + 1] === '/') {
+          pos += 2;
+          break;
+        }
+        pos++;
+      }
+      return text.substring(startPos, pos);
+    }
+
+    function skipString(lastChar: string) {
+      pos++;
+      while(pos < text.length) {
+        if(text[pos] === lastChar) {
+          pos++;
+          return;
+        } else if(text[pos] === '\\') {
+          pos+=2;
+          continue;
+        }
+        pos++;
+      }
+    }
+
+
+    while(pos < text.length - 1) {
+      if(text[pos] === '/' && text[pos + 1] === '/') {
+        result.push(readSingleLineComment());
+      } else if(text[pos] === '/' && text[pos + 1] === '*') {
+        result.push(readMultiLineComment());
+      } else if(text[pos] === "'") {
+        skipString("'");
+      } else if(text[pos] === '"') {
+        skipString('"');
+      } else if(text[pos] === '`') {
+        skipString('`');
+      } else if(text[pos] == '/') {
+        skipString('/');
+      } {
+        pos++;
+      }
+
+    }
+    return result;
+  }
+}
diff --git a/tools/polygerrit-updater/src/utils/polymerClassBuilder.ts b/tools/polygerrit-updater/src/utils/polymerClassBuilder.ts
new file mode 100644
index 0000000..b1a4320
--- /dev/null
+++ b/tools/polygerrit-updater/src/utils/polymerClassBuilder.ts
@@ -0,0 +1,270 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import * as ts from 'typescript';
+import * as codeUtils from './codeUtils';
+import {LegacyLifecycleMethodName, LegacyLifecycleMethodsArray} from '../funcToClassConversion/polymerComponentParser';
+import {SyntaxKind} from 'typescript';
+
+enum PolymerClassMemberType {
+  IsAccessor,
+  Constructor,
+  PolymerPropertiesAccessor,
+  PolymerObserversAccessor,
+  Method,
+  ExistingLifecycleMethod,
+  NewLifecycleMethod,
+  GetAccessor,
+}
+
+type PolymerClassMember = PolymerClassIsAccessor | PolymerClassConstructor | PolymerClassExistingLifecycleMethod | PolymerClassNewLifecycleMethod | PolymerClassSimpleMember;
+
+interface PolymerClassExistingLifecycleMethod {
+  member: ts.MethodDeclaration;
+  memberType: PolymerClassMemberType.ExistingLifecycleMethod;
+  name: string;
+  lifecycleOrder: number;
+  originalPos: number;
+}
+
+interface PolymerClassNewLifecycleMethod {
+  member: ts.MethodDeclaration;
+  memberType: PolymerClassMemberType.NewLifecycleMethod;
+  name: string;
+  lifecycleOrder: number;
+  originalPos: -1
+}
+
+interface PolymerClassIsAccessor {
+  member: ts.GetAccessorDeclaration;
+  memberType: PolymerClassMemberType.IsAccessor;
+  originalPos: -1
+}
+
+interface PolymerClassConstructor {
+  member: ts.ConstructorDeclaration;
+  memberType: PolymerClassMemberType.Constructor;
+  originalPos: -1
+}
+
+interface PolymerClassSimpleMember {
+  memberType: PolymerClassMemberType.PolymerPropertiesAccessor | PolymerClassMemberType.PolymerObserversAccessor | PolymerClassMemberType.Method | PolymerClassMemberType.GetAccessor;
+  member: ts.ClassElement;
+  originalPos: number;
+}
+
+export interface PolymerClassBuilderResult {
+  classDeclaration: ts.ClassDeclaration;
+  generatedComments: string[];
+}
+
+export class PolymerClassBuilder {
+  private readonly members: PolymerClassMember[] = [];
+  public readonly constructorStatements: ts.Statement[] = [];
+  private baseType: ts.ExpressionWithTypeArguments | undefined;
+  private classJsDocComments: string[];
+
+  public constructor(public readonly className: string) {
+    this.classJsDocComments = [];
+  }
+
+  public addIsAccessor(accessor: ts.GetAccessorDeclaration) {
+    this.members.push({
+      member: accessor,
+      memberType: PolymerClassMemberType.IsAccessor,
+      originalPos: -1
+    });
+  }
+
+  public addPolymerPropertiesAccessor(originalPos: number, accessor: ts.GetAccessorDeclaration) {
+    this.members.push({
+      member: accessor,
+      memberType: PolymerClassMemberType.PolymerPropertiesAccessor,
+      originalPos: originalPos
+    });
+  }
+
+  public addPolymerObserversAccessor(originalPos: number, accessor: ts.GetAccessorDeclaration) {
+    this.members.push({
+      member: accessor,
+      memberType: PolymerClassMemberType.PolymerObserversAccessor,
+      originalPos: originalPos
+    });
+  }
+
+
+  public addClassFieldInitializer(name: string | ts.Identifier, initializer: ts.Expression) {
+    const assignment = ts.createAssignment(ts.createPropertyAccess(ts.createThis(), name), initializer);
+    this.constructorStatements.push(codeUtils.addNewLineAfterNode(ts.createExpressionStatement(assignment)));
+  }
+  public addMethod(originalPos: number, method: ts.MethodDeclaration) {
+    this.members.push({
+      member: method,
+      memberType: PolymerClassMemberType.Method,
+      originalPos: originalPos
+    });
+  }
+
+  public addGetAccessor(originalPos: number, accessor: ts.GetAccessorDeclaration) {
+    this.members.push({
+      member: accessor,
+      memberType: PolymerClassMemberType.GetAccessor,
+      originalPos: originalPos
+    });
+  }
+
+  public addLifecycleMethod(name: LegacyLifecycleMethodName, originalPos: number, method: ts.MethodDeclaration) {
+    const lifecycleOrder = LegacyLifecycleMethodsArray.indexOf(name);
+    if(lifecycleOrder < 0) {
+      throw new Error(`Invalid lifecycle name`);
+    }
+    if(originalPos >= 0) {
+      this.members.push({
+        member: method,
+        memberType: PolymerClassMemberType.ExistingLifecycleMethod,
+        originalPos: originalPos,
+        name: name,
+        lifecycleOrder: lifecycleOrder
+      })
+    } else {
+      this.members.push({
+        member: method,
+        memberType: PolymerClassMemberType.NewLifecycleMethod,
+        name: name,
+        lifecycleOrder: lifecycleOrder,
+        originalPos: -1
+      })
+    }
+  }
+
+  public setBaseType(type: ts.ExpressionWithTypeArguments) {
+    if(this.baseType) {
+      throw new Error("Class can have only one base type");
+    }
+    this.baseType = type;
+  }
+
+  public build(): PolymerClassBuilderResult {
+    let heritageClauses: ts.HeritageClause[] = [];
+    if (this.baseType) {
+      const extendClause = ts.createHeritageClause(ts.SyntaxKind.ExtendsKeyword, [this.baseType]);
+      heritageClauses.push(extendClause);
+    }
+    const finalMembers: PolymerClassMember[] = [];
+    const isAccessors = this.members.filter(member => member.memberType === PolymerClassMemberType.IsAccessor);
+    if(isAccessors.length !== 1) {
+      throw new Error("Class must have exactly one 'is'");
+    }
+    finalMembers.push(isAccessors[0]);
+    const constructorMember = this.createConstructor();
+    if(constructorMember) {
+      finalMembers.push(constructorMember);
+    }
+
+    const newLifecycleMethods: PolymerClassNewLifecycleMethod[] = [];
+    this.members.forEach(member => {
+      if(member.memberType === PolymerClassMemberType.NewLifecycleMethod) {
+        newLifecycleMethods.push(member);
+      }
+    });
+
+    const methodsWithKnownPosition = this.members.filter(member => member.originalPos >= 0);
+    methodsWithKnownPosition.sort((a, b) => a.originalPos - b.originalPos);
+
+    finalMembers.push(...methodsWithKnownPosition);
+
+
+    for(const newLifecycleMethod of newLifecycleMethods) {
+      //Number of methods is small - use brute force solution
+      let closestNextIndex = -1;
+      let closestNextOrderDiff: number = LegacyLifecycleMethodsArray.length;
+      let closestPrevIndex = -1;
+      let closestPrevOrderDiff: number = LegacyLifecycleMethodsArray.length;
+      for (let i = 0; i < finalMembers.length; i++) {
+        const member = finalMembers[i];
+        if (member.memberType !== PolymerClassMemberType.NewLifecycleMethod && member.memberType !== PolymerClassMemberType.ExistingLifecycleMethod) {
+          continue;
+        }
+        const orderDiff = member.lifecycleOrder - newLifecycleMethod.lifecycleOrder;
+        if (orderDiff > 0) {
+          if (orderDiff < closestNextOrderDiff) {
+            closestNextIndex = i;
+            closestNextOrderDiff = orderDiff;
+          }
+        } else if (orderDiff < 0) {
+          if (orderDiff < closestPrevOrderDiff) {
+            closestPrevIndex = i;
+            closestPrevOrderDiff = orderDiff;
+          }
+        }
+      }
+      let insertIndex;
+      if (closestNextIndex !== -1 || closestPrevIndex !== -1) {
+        insertIndex = closestNextOrderDiff < closestPrevOrderDiff ?
+            closestNextIndex : closestPrevIndex + 1;
+      } else {
+        insertIndex = Math.max(
+            finalMembers.findIndex(m => m.memberType === PolymerClassMemberType.Constructor),
+            finalMembers.findIndex(m => m.memberType === PolymerClassMemberType.IsAccessor),
+            finalMembers.findIndex(m => m.memberType === PolymerClassMemberType.PolymerPropertiesAccessor),
+            finalMembers.findIndex(m => m.memberType === PolymerClassMemberType.PolymerObserversAccessor),
+        );
+        if(insertIndex < 0) {
+          insertIndex = finalMembers.length;
+        } else {
+          insertIndex++;//Insert after
+        }
+      }
+      finalMembers.splice(insertIndex, 0, newLifecycleMethod);
+    }
+    //Asserts about finalMembers
+    const nonConstructorMembers = finalMembers.filter(m => m.memberType !== PolymerClassMemberType.Constructor);
+
+    if(nonConstructorMembers.length !== this.members.length) {
+      throw new Error(`Internal error! Some methods are missed`);
+    }
+    let classDeclaration = ts.createClassDeclaration(undefined, undefined, this.className, undefined, heritageClauses, finalMembers.map(m => m.member))
+    const generatedComments: string[] = [];
+    if(this.classJsDocComments.length > 0) {
+      const commentContent = '*\n' + this.classJsDocComments.map(line => `* ${line}`).join('\n') + '\n';
+      classDeclaration = ts.addSyntheticLeadingComment(classDeclaration, ts.SyntaxKind.MultiLineCommentTrivia, commentContent, true);
+      generatedComments.push(`/*${commentContent}*/`);
+    }
+    return {
+      classDeclaration,
+      generatedComments,
+    };
+
+  }
+
+  private createConstructor(): PolymerClassConstructor | null {
+    if(this.constructorStatements.length === 0) {
+      return null;
+    }
+    let superCall: ts.CallExpression = ts.createCall(ts.createSuper(), [], []);
+    const superCallExpression = ts.createExpressionStatement(superCall);
+    const statements = [superCallExpression, ...this.constructorStatements];
+    const constructorDeclaration = ts.createConstructor([], [], [], ts.createBlock(statements, true));
+
+    return {
+      memberType: PolymerClassMemberType.Constructor,
+      member: constructorDeclaration,
+      originalPos: -1
+    };
+  }
+
+  public addClassJSDocComments(lines: string[]) {
+    this.classJsDocComments.push(...lines);
+  }
+}
\ No newline at end of file
diff --git a/tools/polygerrit-updater/src/utils/unexpectedValue.ts b/tools/polygerrit-updater/src/utils/unexpectedValue.ts
new file mode 100644
index 0000000..690c283
--- /dev/null
+++ b/tools/polygerrit-updater/src/utils/unexpectedValue.ts
@@ -0,0 +1,17 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+export function unexpectedValue<T>(x: T): never {
+  throw new Error(`Unexpected value '${x}'`);
+}
diff --git a/tools/polygerrit-updater/tsconfig.json b/tools/polygerrit-updater/tsconfig.json
new file mode 100644
index 0000000..37ff1b2
--- /dev/null
+++ b/tools/polygerrit-updater/tsconfig.json
@@ -0,0 +1,67 @@
+{
+  "compilerOptions": {
+    /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
+    "target": "es2015",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
+    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
+    // "lib": [],                             /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                       /* Allow javascript files to be compiled. */
+    // "checkJs": true,                       /* Report errors in .js files. */
+    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
+    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    "sourceMap": true,                     /* Generates corresponding '.map' file. */
+    // "outFile": "./",                       /* Concatenate and emit output to single file. */
+    "outDir": "./js",                        /* Redirect output structure to the directory. */
+    "rootDir": ".",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                     /* Enable project compilation */
+    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
+    // "removeComments": true,                /* Do not emit comments to output. */
+    // "noEmit": true,                        /* Do not emit outputs. */
+    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true,                           /* Enable all strict type-checking options. */
+    "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,              /* Enable strict null checks. */
+    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                /* Report errors on unused locals. */
+    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+
+    /* Module Resolution Options */
+    "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    "paths": {
+      "*": [ "node_modules/*" ]
+    },                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                       /* List of folders to include type definitions from. */
+    // "types": [],                           /* Type declaration files to be included in compilation. */
+    "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
+
+  },
+  "include": ["./src/**/*"]
+}