diff --git a/extensions/css-language-features/server/src/test/completion.test.ts b/extensions/css-language-features/server/src/test/completion.test.ts
index 8885cc01fc1..3a832600355 100644
--- a/extensions/css-language-features/server/src/test/completion.test.ts
+++ b/extensions/css-language-features/server/src/test/completion.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import * as path from 'path';
diff --git a/extensions/git/src/test/git.test.ts b/extensions/git/src/test/git.test.ts
index eee43347351..6b7af8c8684 100644
--- a/extensions/git/src/test/git.test.ts
+++ b/extensions/git/src/test/git.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import 'mocha';
 import { GitStatusParser, parseGitCommit, parseGitmodules, parseLsTree, parseLsFiles } from '../git';
 import * as assert from 'assert';
diff --git a/extensions/html-language-features/server/src/test/completions.test.ts b/extensions/html-language-features/server/src/test/completions.test.ts
index 2129433b567..c28daf9f0c2 100644
--- a/extensions/html-language-features/server/src/test/completions.test.ts
+++ b/extensions/html-language-features/server/src/test/completions.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import * as path from 'path';
diff --git a/extensions/html-language-features/server/src/test/documentContext.test.ts b/extensions/html-language-features/server/src/test/documentContext.test.ts
index a017500e37c..612c0063c05 100644
--- a/extensions/html-language-features/server/src/test/documentContext.test.ts
+++ b/extensions/html-language-features/server/src/test/documentContext.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import * as assert from 'assert';
 import { getDocumentContext } from '../utils/documentContext';
 
diff --git a/extensions/html-language-features/server/src/test/embedded.test.ts b/extensions/html-language-features/server/src/test/embedded.test.ts
index ae63ed167fc..961dc96db23 100644
--- a/extensions/html-language-features/server/src/test/embedded.test.ts
+++ b/extensions/html-language-features/server/src/test/embedded.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import * as embeddedSupport from '../modes/embeddedSupport';
diff --git a/extensions/html-language-features/server/src/test/folding.test.ts b/extensions/html-language-features/server/src/test/folding.test.ts
index bf34a7dab05..1ca958dcdf3 100644
--- a/extensions/html-language-features/server/src/test/folding.test.ts
+++ b/extensions/html-language-features/server/src/test/folding.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import { TextDocument } from 'vscode-languageserver';
diff --git a/extensions/html-language-features/server/src/test/formatting.test.ts b/extensions/html-language-features/server/src/test/formatting.test.ts
index 150dbd33f2e..46de4b56d7c 100644
--- a/extensions/html-language-features/server/src/test/formatting.test.ts
+++ b/extensions/html-language-features/server/src/test/formatting.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import 'mocha';
 import * as path from 'path';
 import * as fs from 'fs';
diff --git a/extensions/html-language-features/server/src/test/words.test.ts b/extensions/html-language-features/server/src/test/words.test.ts
index 55326de01ce..e094bfb4251 100644
--- a/extensions/html-language-features/server/src/test/words.test.ts
+++ b/extensions/html-language-features/server/src/test/words.test.ts
@@ -2,8 +2,6 @@
  *  Copyright (c) Microsoft Corporation. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
-'use strict';
-
 import * as assert from 'assert';
 import * as words from '../utils/strings';
 
diff --git a/extensions/search-rg/src/test/searchrg.test.ts b/extensions/search-rg/src/test/searchrg.test.ts
index 6c5f3e172a5..d16d37557f5 100644
--- a/extensions/search-rg/src/test/searchrg.test.ts
+++ b/extensions/search-rg/src/test/searchrg.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import * as vscode from 'vscode';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/commands.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/commands.test.ts
index f43e17717b1..4f227d8052e 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/commands.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/commands.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import { join } from 'path';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/editor.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/editor.test.ts
index 32d0fc3bac1..80ad28ddf57 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/editor.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/editor.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import { workspace, window, Position, Range, commands, TextEditor, TextDocument, TextEditorCursorStyle, TextEditorLineNumbersStyle, SnippetString, Selection } from 'vscode';
 import { createRandomFile, deleteFile, closeAllEditors } from '../utils';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
index b9ed8ab8526..d3c5c788d08 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/env.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import { env } from 'vscode';
 
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/languages.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/languages.test.ts
index 80af3e16755..7979988872b 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/languages.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/languages.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import { join } from 'path';
 import * as vscode from 'vscode';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/quickInput.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/quickInput.test.ts
index 04f8ba296e3..ff1329efd21 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/quickInput.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/quickInput.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import { window, commands } from 'vscode';
 import { closeAllEditors } from '../utils';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/window.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/window.test.ts
index a3300abd7a8..7105402f7f4 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/window.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/window.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import { workspace, window, commands, ViewColumn, TextEditorViewColumnChangeEvent, Uri, Selection, Position, CancellationTokenSource, TextEditorSelectionChangeKind, Terminal } from 'vscode';
 import { join } from 'path';
diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/workspace.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.test.ts
index 2b3ffd64919..daec5613ffa 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/workspace.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import * as vscode from 'vscode';
 import { createRandomFile, deleteFile, closeAllEditors, pathEquals, rndName } from '../utils';
diff --git a/extensions/vscode-api-tests/src/workspace-tests/workspace.test.ts b/extensions/vscode-api-tests/src/workspace-tests/workspace.test.ts
index 5453c2adec3..f28967468a5 100644
--- a/extensions/vscode-api-tests/src/workspace-tests/workspace.test.ts
+++ b/extensions/vscode-api-tests/src/workspace-tests/workspace.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import * as assert from 'assert';
 import * as vscode from 'vscode';
 import { closeAllEditors, pathEquals } from '../utils';
diff --git a/extensions/vscode-colorize-tests/src/colorizer.test.ts b/extensions/vscode-colorize-tests/src/colorizer.test.ts
index 7fb9ae02e62..82892577bdf 100644
--- a/extensions/vscode-colorize-tests/src/colorizer.test.ts
+++ b/extensions/vscode-colorize-tests/src/colorizer.test.ts
@@ -3,8 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-'use strict';
-
 import 'mocha';
 import * as assert from 'assert';
 import { commands, Uri } from 'vscode';