diff --git a/polygerrit-ui/app/utils/path-list-util_test.js b/polygerrit-ui/app/utils/path-list-util_test.js
deleted file mode 100644
index 4d06344..0000000
--- a/polygerrit-ui/app/utils/path-list-util_test.js
+++ /dev/null
@@ -1,161 +0,0 @@
-/**
- * @license
- * Copyright (C) 2016 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 '../test/common-test-setup-karma.js';
-import {SpecialFilePath} from '../constants/constants.js';
-import {
-  addUnmodifiedFiles,
-  computeDisplayPath,
-  isMagicPath,
-  specialFilePathCompare, truncatePath,
-} from './path-list-util.js';
-
-suite('path-list-utl tests', () => {
-  test('special sort', () => {
-    const testFiles = [
-      '/a.h',
-      '/MERGE_LIST',
-      '/a.cpp',
-      '/COMMIT_MSG',
-      '/asdasd',
-      '/mrPeanutbutter.py',
-    ];
-    assert.deepEqual(
-        testFiles.sort(specialFilePathCompare),
-        [
-          '/COMMIT_MSG',
-          '/MERGE_LIST',
-          '/a.h',
-          '/a.cpp',
-          '/asdasd',
-          '/mrPeanutbutter.py',
-        ]);
-  });
-
-  test('special file path sorting', () => {
-    assert.deepEqual(
-        ['.b', '/COMMIT_MSG', '.a', 'file'].sort(
-            specialFilePathCompare),
-        ['/COMMIT_MSG', '.a', '.b', 'file']);
-
-    assert.deepEqual(
-        ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.h'].sort(
-            specialFilePathCompare),
-        ['/COMMIT_MSG', '.b', 'foo/bar/baz.h', 'foo/bar/baz.cc']);
-
-    assert.deepEqual(
-        ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.hpp'].sort(
-            specialFilePathCompare),
-        ['/COMMIT_MSG', '.b', 'foo/bar/baz.hpp', 'foo/bar/baz.cc']);
-
-    assert.deepEqual(
-        ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.hxx'].sort(
-            specialFilePathCompare),
-        ['/COMMIT_MSG', '.b', 'foo/bar/baz.hxx', 'foo/bar/baz.cc']);
-
-    assert.deepEqual(
-        ['foo/bar.h', 'foo/bar.hxx', 'foo/bar.hpp'].sort(
-            specialFilePathCompare),
-        ['foo/bar.h', 'foo/bar.hpp', 'foo/bar.hxx']);
-
-    // Regression test for Issue 4448.
-    assert.deepEqual(
-        [
-          'minidump/minidump_memory_writer.cc',
-          'minidump/minidump_memory_writer.h',
-          'minidump/minidump_thread_writer.cc',
-          'minidump/minidump_thread_writer.h',
-        ].sort(specialFilePathCompare),
-        [
-          'minidump/minidump_memory_writer.h',
-          'minidump/minidump_memory_writer.cc',
-          'minidump/minidump_thread_writer.h',
-          'minidump/minidump_thread_writer.cc',
-        ]);
-
-    // Regression test for Issue 4545.
-    assert.deepEqual(
-        [
-          'task_test.go',
-          'task.go',
-        ].sort(specialFilePathCompare),
-        [
-          'task.go',
-          'task_test.go',
-        ]);
-  });
-
-  test('file display name', () => {
-    assert.equal(computeDisplayPath('/foo/bar/baz'), '/foo/bar/baz');
-    assert.equal(computeDisplayPath('/foobarbaz'), '/foobarbaz');
-    assert.equal(computeDisplayPath('/COMMIT_MSG'), 'Commit message');
-    assert.equal(computeDisplayPath('/MERGE_LIST'), 'Merge list');
-  });
-
-  test('isMagicPath', () => {
-    assert.isFalse(isMagicPath(undefined));
-    assert.isFalse(isMagicPath('/foo.cc'));
-    assert.isTrue(isMagicPath('/COMMIT_MSG'));
-    assert.isTrue(isMagicPath('/MERGE_LIST'));
-  });
-
-  test('patchset level comments are hidden', () => {
-    const commentedPaths = {
-      [SpecialFilePath.PATCHSET_LEVEL_COMMENTS]: true,
-      'file1.txt': true,
-    };
-
-    const files = {'file2.txt': {status: 'M'}};
-    addUnmodifiedFiles(files, commentedPaths);
-    assert.equal(files['file1.txt'].status, 'U');
-    assert.equal(files['file2.txt'].status, 'M');
-    assert.isFalse(files.hasOwnProperty(
-        SpecialFilePath.PATCHSET_LEVEL_COMMENTS));
-  });
-
-  test('truncatePath with long path should add ellipsis', () => {
-    let path = 'level1/level2/level3/level4/file.js';
-    let shortenedPath = truncatePath(path);
-    // The expected path is truncated with an ellipsis.
-    const expectedPath = '\u2026/file.js';
-    assert.equal(shortenedPath, expectedPath);
-
-    path = 'level2/file.js';
-    shortenedPath = truncatePath(path);
-    assert.equal(shortenedPath, expectedPath);
-  });
-
-  test('truncatePath with opt_threshold', () => {
-    let path = 'level1/level2/level3/level4/file.js';
-    let shortenedPath = truncatePath(path, 2);
-    // The expected path is truncated with an ellipsis.
-    const expectedPath = '\u2026/level4/file.js';
-    assert.equal(shortenedPath, expectedPath);
-
-    path = 'level2/file.js';
-    shortenedPath = truncatePath(path, 2);
-    assert.equal(shortenedPath, path);
-  });
-
-  test('truncatePath with short path should not add ellipsis', () => {
-    const path = 'file.js';
-    const expectedPath = 'file.js';
-    const shortenedPath = truncatePath(path);
-    assert.equal(shortenedPath, expectedPath);
-  });
-});
-
diff --git a/polygerrit-ui/app/utils/path-list-util_test.ts b/polygerrit-ui/app/utils/path-list-util_test.ts
new file mode 100644
index 0000000..79b5f09
--- /dev/null
+++ b/polygerrit-ui/app/utils/path-list-util_test.ts
@@ -0,0 +1,170 @@
+/**
+ * @license
+ * Copyright (C) 2016 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 '../test/common-test-setup-karma';
+import {FileInfoStatus, SpecialFilePath} from '../constants/constants';
+import {
+  addUnmodifiedFiles,
+  computeDisplayPath,
+  isMagicPath,
+  specialFilePathCompare,
+  truncatePath,
+} from './path-list-util';
+import {FileInfo} from '../api/rest-api';
+import {hasOwnProperty} from './common-util';
+
+suite('path-list-utl tests', () => {
+  test('special sort', () => {
+    const testFiles = [
+      '/a.h',
+      '/MERGE_LIST',
+      '/a.cpp',
+      '/COMMIT_MSG',
+      '/asdasd',
+      '/mrPeanutbutter.py',
+    ];
+    assert.deepEqual(testFiles.sort(specialFilePathCompare), [
+      '/COMMIT_MSG',
+      '/MERGE_LIST',
+      '/a.h',
+      '/a.cpp',
+      '/asdasd',
+      '/mrPeanutbutter.py',
+    ]);
+  });
+
+  test('special file path sorting', () => {
+    assert.deepEqual(
+      ['.b', '/COMMIT_MSG', '.a', 'file'].sort(specialFilePathCompare),
+      ['/COMMIT_MSG', '.a', '.b', 'file']
+    );
+
+    assert.deepEqual(
+      ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.h'].sort(
+        specialFilePathCompare
+      ),
+      ['/COMMIT_MSG', '.b', 'foo/bar/baz.h', 'foo/bar/baz.cc']
+    );
+
+    assert.deepEqual(
+      ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.hpp'].sort(
+        specialFilePathCompare
+      ),
+      ['/COMMIT_MSG', '.b', 'foo/bar/baz.hpp', 'foo/bar/baz.cc']
+    );
+
+    assert.deepEqual(
+      ['.b', '/COMMIT_MSG', 'foo/bar/baz.cc', 'foo/bar/baz.hxx'].sort(
+        specialFilePathCompare
+      ),
+      ['/COMMIT_MSG', '.b', 'foo/bar/baz.hxx', 'foo/bar/baz.cc']
+    );
+
+    assert.deepEqual(
+      ['foo/bar.h', 'foo/bar.hxx', 'foo/bar.hpp'].sort(specialFilePathCompare),
+      ['foo/bar.h', 'foo/bar.hpp', 'foo/bar.hxx']
+    );
+
+    // Regression test for Issue 4448.
+    assert.deepEqual(
+      [
+        'minidump/minidump_memory_writer.cc',
+        'minidump/minidump_memory_writer.h',
+        'minidump/minidump_thread_writer.cc',
+        'minidump/minidump_thread_writer.h',
+      ].sort(specialFilePathCompare),
+      [
+        'minidump/minidump_memory_writer.h',
+        'minidump/minidump_memory_writer.cc',
+        'minidump/minidump_thread_writer.h',
+        'minidump/minidump_thread_writer.cc',
+      ]
+    );
+
+    // Regression test for Issue 4545.
+    assert.deepEqual(['task_test.go', 'task.go'].sort(specialFilePathCompare), [
+      'task.go',
+      'task_test.go',
+    ]);
+  });
+
+  test('file display name', () => {
+    assert.equal(computeDisplayPath('/foo/bar/baz'), '/foo/bar/baz');
+    assert.equal(computeDisplayPath('/foobarbaz'), '/foobarbaz');
+    assert.equal(computeDisplayPath('/COMMIT_MSG'), 'Commit message');
+    assert.equal(computeDisplayPath('/MERGE_LIST'), 'Merge list');
+  });
+
+  test('isMagicPath', () => {
+    assert.isFalse(isMagicPath(undefined));
+    assert.isFalse(isMagicPath('/foo.cc'));
+    assert.isTrue(isMagicPath('/COMMIT_MSG'));
+    assert.isTrue(isMagicPath('/MERGE_LIST'));
+  });
+
+  test('patchset level comments are hidden', () => {
+    const commentedPaths = {
+      [SpecialFilePath.PATCHSET_LEVEL_COMMENTS]: true,
+      'file1.txt': true,
+    };
+
+    const files: {[filename: string]: FileInfo} = {
+      'file2.txt': {
+        status: FileInfoStatus.REWRITTEN,
+        size_delta: 10,
+        size: 10,
+      },
+    };
+    addUnmodifiedFiles(files, commentedPaths);
+    assert.equal(files['file1.txt'].status, FileInfoStatus.UNMODIFIED);
+    assert.equal(files['file2.txt'].status, FileInfoStatus.REWRITTEN);
+    assert.isFalse(
+      hasOwnProperty(files, SpecialFilePath.PATCHSET_LEVEL_COMMENTS)
+    );
+  });
+
+  test('truncatePath with long path should add ellipsis', () => {
+    let path = 'level1/level2/level3/level4/file.js';
+    let shortenedPath = truncatePath(path);
+    // The expected path is truncated with an ellipsis.
+    const expectedPath = '\u2026/file.js';
+    assert.equal(shortenedPath, expectedPath);
+
+    path = 'level2/file.js';
+    shortenedPath = truncatePath(path);
+    assert.equal(shortenedPath, expectedPath);
+  });
+
+  test('truncatePath with opt_threshold', () => {
+    let path = 'level1/level2/level3/level4/file.js';
+    let shortenedPath = truncatePath(path, 2);
+    // The expected path is truncated with an ellipsis.
+    const expectedPath = '\u2026/level4/file.js';
+    assert.equal(shortenedPath, expectedPath);
+
+    path = 'level2/file.js';
+    shortenedPath = truncatePath(path, 2);
+    assert.equal(shortenedPath, path);
+  });
+
+  test('truncatePath with short path should not add ellipsis', () => {
+    const path = 'file.js';
+    const expectedPath = 'file.js';
+    const shortenedPath = truncatePath(path);
+    assert.equal(shortenedPath, expectedPath);
+  });
+});