diff --git a/polygerrit-ui/app/api/gerrit.ts b/polygerrit-ui/app/api/gerrit.ts
index a5f7731..404907a 100644
--- a/polygerrit-ui/app/api/gerrit.ts
+++ b/polygerrit-ui/app/api/gerrit.ts
@@ -17,7 +17,7 @@
 export declare interface Gerrit {
   install(
     callback: (plugin: PluginApi) => void,
-    opt_version?: string,
+    version?: string,
     src?: string
   ): void;
   styles: Styles;
diff --git a/polygerrit-ui/app/services/gr-auth/gr-auth.ts b/polygerrit-ui/app/services/gr-auth/gr-auth.ts
index f41c83d..945d6f9 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth.ts
@@ -50,5 +50,5 @@
   /**
    * Perform network fetch with authentication.
    */
-  fetch(url: string, opt_options?: AuthRequestInit): Promise<Response>;
+  fetch(url: string, options?: AuthRequestInit): Promise<Response>;
 }
diff --git a/polygerrit-ui/app/services/gr-auth/gr-auth_impl.ts b/polygerrit-ui/app/services/gr-auth/gr-auth_impl.ts
index 51b8bfd..2312fc9 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth_impl.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth_impl.ts
@@ -162,18 +162,18 @@
   /**
    * Perform network fetch with authentication.
    */
-  fetch(url: string, opt_options?: AuthRequestInit): Promise<Response> {
-    const options: AuthRequestInitWithHeaders = {
+  fetch(url: string, options?: AuthRequestInit): Promise<Response> {
+    const optionsWithHeaders: AuthRequestInitWithHeaders = {
       headers: new Headers(),
       ...this.defaultOptions,
-      ...opt_options,
+      ...options,
     };
     if (this.type === AuthType.ACCESS_TOKEN) {
       return this._getAccessToken().then(accessToken =>
-        this._fetchWithAccessToken(url, options, accessToken)
+        this._fetchWithAccessToken(url, optionsWithHeaders, accessToken)
       );
     } else {
-      return this._fetchWithXsrfToken(url, options);
+      return this._fetchWithXsrfToken(url, optionsWithHeaders);
     }
   }
 
diff --git a/polygerrit-ui/app/services/gr-auth/gr-auth_mock.ts b/polygerrit-ui/app/services/gr-auth/gr-auth_mock.ts
index 3e14aa7..9cdd37e 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth_mock.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth_mock.ts
@@ -57,7 +57,7 @@
 
   setup(_getToken: GetTokenCallback, _defaultOptions: DefaultAuthOptions) {}
 
-  fetch(_url: string, _opt_options?: AuthRequestInit): Promise<Response> {
+  fetch(_url: string, _options?: AuthRequestInit): Promise<Response> {
     return Promise.resolve(new Response());
   }
 }
diff --git a/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts b/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
index e64cec1..b9cef86 100644
--- a/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
+++ b/polygerrit-ui/app/services/gr-auth/gr-auth_test.ts
@@ -208,9 +208,9 @@
 
     let getToken: sinon.SinonStub;
 
-    const makeToken = (opt_accessToken?: string) => {
+    const makeToken = (accessToken?: string) => {
       return {
-        access_token: opt_accessToken || 'zbaz',
+        access_token: accessToken || 'zbaz',
         expires_at: new Date(Date.now() + 10e8).getTime(),
       };
     };
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
index f552762..49259b4 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
@@ -29,7 +29,7 @@
     eventName: string,
     eventValue?: EventValue,
     eventDetails?: EventDetails,
-    opt_noLog?: boolean
+    noLog?: boolean
   ): void;
 
   appStarted(): void;
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
index 5b6e852..55bb64c 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
@@ -131,8 +131,8 @@
   };
   // TODO(dmfilippov): TS-fix-any unclear what is context
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const catchErrors = function (opt_context?: any) {
-    const context = opt_context || window;
+  const catchErrors = function (context?: any) {
+    context = context || window;
     const oldOnError = context.onerror;
     context.onerror = (
       event: Event | string,
@@ -387,18 +387,18 @@
       // We cache until metrics plugin is loaded
       this.pending.push([eventInfo, noLog]);
       if (this._isMetricsPluginLoaded()) {
-        this.pending.forEach(([eventInfo, opt_noLog]) => {
-          this._reportEvent(eventInfo, opt_noLog);
+        this.pending.forEach(([eventInfo, noLog]) => {
+          this._reportEvent(eventInfo, noLog);
         });
         this.pending = [];
       }
     }
   }
 
-  private _reportEvent(eventInfo: EventInfo, opt_noLog?: boolean) {
+  private _reportEvent(eventInfo: EventInfo, noLog?: boolean) {
     const {type, value, name, eventDetails} = eventInfo;
     document.dispatchEvent(new CustomEvent(type, {detail: eventInfo}));
-    if (opt_noLog) {
+    if (noLog) {
       return;
     }
     if (type !== ERROR.TYPE) {
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
index 83f1017..d570163 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl_test.ts
@@ -1191,7 +1191,7 @@
         ],
         [{_number: 3, project: 'test/test'}],
       ] as unknown as ParsedJSON);
-      // When opt_query instanceof Array, fetchJSON returns
+      // When query instanceof Array, fetchJSON returns
       // Array<Array<Object>>.
       await element.getChangesForMultipleQueries(undefined, []);
       assert.equal(Object.keys(element._projectLookup).length, 3);
@@ -1210,7 +1210,7 @@
         {_number: 3, project: 'test/test'},
       ] as unknown as ParsedJSON);
 
-      // When opt_query !instanceof Array, fetchJSON returns Array<Object>.
+      // When query !instanceof Array, fetchJSON returns Array<Object>.
       await element.getChanges();
       assert.equal(Object.keys(element._projectLookup).length, 3);
       const project1 = await element.getFromProjectLookup(1 as NumericChangeId);
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
index 86276d1..b1f1884 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
@@ -199,8 +199,8 @@
 
   getChangeDetail(
     changeNum?: number | string,
-    opt_errFn?: ErrorCallback,
-    opt_cancelCondition?: Function
+    errFn?: ErrorCallback,
+    cancelCondition?: Function
   ): Promise<ParsedChangeInfo | undefined>;
 
   /**
diff --git a/polygerrit-ui/app/services/storage/gr-storage_test.ts b/polygerrit-ui/app/services/storage/gr-storage_test.ts
index b79a8d7..72878f8 100644
--- a/polygerrit-ui/app/services/storage/gr-storage_test.ts
+++ b/polygerrit-ui/app/services/storage/gr-storage_test.ts
@@ -11,7 +11,7 @@
 suite('gr-storage tests', () => {
   let grStorage: GrStorageService;
 
-  function mockStorage(opt_quotaExceeded: boolean): Storage {
+  function mockStorage(quotaExceeded: boolean): Storage {
     return {
       getItem(key: string) {
         return (this as any)[key];
@@ -20,7 +20,7 @@
         delete (this as any)[key];
       },
       setItem(key: string, value: string) {
-        if (opt_quotaExceeded) {
+        if (quotaExceeded) {
           throw new DOMException('error', 'QuotaExceededError');
         }
         (this as any)[key] = value;
diff --git a/polygerrit-ui/app/utils/change-util.ts b/polygerrit-ui/app/utils/change-util.ts
index 1b0a71d..5dda8d6 100644
--- a/polygerrit-ui/app/utils/change-util.ts
+++ b/polygerrit-ui/app/utils/change-util.ts
@@ -154,7 +154,7 @@
 
 export function changeStatuses(
   change: ChangeInfo,
-  opt_options?: ChangeStatusesOptions
+  options?: ChangeStatusesOptions
 ): ChangeStates[] {
   const states = [];
   if (change.status === ChangeStatus.MERGED) {
@@ -163,10 +163,7 @@
   if (change.status === ChangeStatus.ABANDONED) {
     return [ChangeStates.ABANDONED];
   }
-  if (
-    change.mergeable === false ||
-    (opt_options && opt_options.mergeable === false)
-  ) {
+  if (change.mergeable === false || (options && options.mergeable === false)) {
     // 'mergeable' prop may not always exist (@see Issue 6819)
     states.push(ChangeStates.MERGE_CONFLICT);
   } else if (change.contains_git_conflicts) {
@@ -181,12 +178,12 @@
 
   // If there are any pre-defined statuses, only return those. Otherwise,
   // will determine the derived status.
-  if (states.length || !opt_options) {
+  if (states.length || !options) {
     return states;
   }
 
   // If no missing requirements, either active or ready to submit.
-  if (change.submittable && opt_options.submitEnabled) {
+  if (change.submittable && options.submitEnabled) {
     states.push(ChangeStates.READY_TO_SUBMIT);
   } else {
     // Otherwise it is active.
diff --git a/polygerrit-ui/app/utils/path-list-util_test.ts b/polygerrit-ui/app/utils/path-list-util_test.ts
index 3c9e0d3..cdd8182 100644
--- a/polygerrit-ui/app/utils/path-list-util_test.ts
+++ b/polygerrit-ui/app/utils/path-list-util_test.ts
@@ -144,7 +144,7 @@
     assert.equal(shortenedPath, expectedPath);
   });
 
-  test('truncatePath with opt_threshold', () => {
+  test('truncatePath with threshold', () => {
     let path = 'level1/level2/level3/level4/file.js';
     let shortenedPath = truncatePath(path, 2);
     // The expected path is truncated with an ellipsis.