diff --git a/extensions/typescript-language-features/src/test/completions.test.ts b/extensions/typescript-language-features/src/test/completions.test.ts
index 644871101d0..6cb29a8b66d 100644
--- a/extensions/typescript-language-features/src/test/completions.test.ts
+++ b/extensions/typescript-language-features/src/test/completions.test.ts
@@ -3,37 +3,14 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import * as assert from 'assert';
 import 'mocha';
 import * as vscode from 'vscode';
 import { disposeAll } from '../utils/dispose';
-import { createTestEditor, joinLines, wait } from './testUtils';
 import { acceptFirstSuggestion, typeCommitCharacter } from './suggestTestHelpers';
+import { assertEditorContents, Config, createTestEditor, joinLines, updateConfig, VsCodeConfiguration, wait } from './testUtils';
 
 const testDocumentUri = vscode.Uri.parse('untitled:test.ts');
 
-type VsCodeConfiguration = { [key: string]: any };
-
-async function updateConfig(newConfig: VsCodeConfiguration): Promise<VsCodeConfiguration> {
-	const oldConfig: VsCodeConfiguration = {};
-	const config = vscode.workspace.getConfiguration(undefined, testDocumentUri);
-	for (const configKey of Object.keys(newConfig)) {
-		oldConfig[configKey] = config.get(configKey);
-		await new Promise((resolve, reject) =>
-			config.update(configKey, newConfig[configKey], vscode.ConfigurationTarget.Global)
-				.then(() => resolve(), reject));
-	}
-	return oldConfig;
-}
-
-namespace Config {
-	export const autoClosingBrackets = 'editor.autoClosingBrackets';
-	export const completeFunctionCalls = 'typescript.suggest.completeFunctionCalls';
-	export const insertMode = 'editor.suggest.insertMode';
-	export const snippetSuggestions = 'editor.snippetSuggestions';
-	export const suggestSelection = 'editor.suggestSelection';
-}
-
 const insertModes = Object.freeze(['insert', 'replace']);
 
 suite('TypeScript Completions', () => {
@@ -52,28 +29,27 @@ suite('TypeScript Completions', () => {
 		await wait(100);
 
 		// Save off config and apply defaults
-		oldConfig = await updateConfig(configDefaults);
+		oldConfig = await updateConfig(testDocumentUri, configDefaults);
 	});
 
 	teardown(async () => {
 		disposeAll(_disposables);
 
 		// Restore config
-		await updateConfig(oldConfig);
+		await updateConfig(testDocumentUri, oldConfig);
 
 		return vscode.commands.executeCommand('workbench.action.closeAllEditors');
 	});
 
 	test('Basic var completion', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`const abcdef = 123;`,
 				`ab$0;`
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`const abcdef = 123;`,
 					`abcdef;`
@@ -85,14 +61,14 @@ suite('TypeScript Completions', () => {
 
 	test('Should treat period as commit character for var completions', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`const abcdef = 123;`,
 				`ab$0;`
 			);
 
-			const document = await typeCommitCharacter(testDocumentUri, '.', _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await typeCommitCharacter(testDocumentUri, '.', _disposables);
+
+			assertEditorContents(editor,
 				joinLines(
 					`const abcdef = 123;`,
 					`abcdef.;`
@@ -103,14 +79,14 @@ suite('TypeScript Completions', () => {
 
 	test('Should treat paren as commit character for function completions', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`function abcdef() {};`,
 				`ab$0;`
 			);
 
-			const document = await typeCommitCharacter(testDocumentUri, '(', _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await typeCommitCharacter(testDocumentUri, '(', _disposables);
+
+			assertEditorContents(editor,
 				joinLines(
 					`function abcdef() {};`,
 					`abcdef();`
@@ -120,14 +96,13 @@ suite('TypeScript Completions', () => {
 
 	test('Should insert backets when completing dot properties with spaces in name', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				'const x = { "hello world": 1 };',
 				'x.$0'
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					'const x = { "hello world": 1 };',
 					'x["hello world"]'
@@ -140,14 +115,14 @@ suite('TypeScript Completions', () => {
 			{ char: '.', insert: '.' },
 			{ char: '(', insert: '()' },
 		]) {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				'const x = { "hello world2": 1 };',
 				'x.$0'
 			);
 
-			const document = await typeCommitCharacter(testDocumentUri, char, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await typeCommitCharacter(testDocumentUri, char, _disposables);
+
+			assertEditorContents(editor,
 				joinLines(
 					'const x = { "hello world2": 1 };',
 					`x["hello world2"]${insert}`
@@ -161,14 +136,13 @@ suite('TypeScript Completions', () => {
 	test('Should not prioritize bracket accessor completions. #63100', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
 			// 'a' should be first entry in completion list
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				'const x = { "z-z": 1, a: 1 };',
 				'x.$0'
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					'const x = { "z-z": 1, a: 1 };',
 					'x.a'
@@ -178,7 +152,7 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a string completion should replace the entire string. #53962', async () => {
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			'interface TFunction {',
 			`  (_: 'abc.abc2', __ ?: {}): string;`,
 			`  (_: 'abc.abc', __?: {}): string;`,
@@ -187,9 +161,8 @@ suite('TypeScript Completions', () => {
 			`f('abc.abc$0')`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				'interface TFunction {',
 				`  (_: 'abc.abc2', __ ?: {}): string;`,
@@ -201,17 +174,16 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('completeFunctionCalls should complete function parameters when at end of word', async () => {
-		await updateConfig({ [Config.completeFunctionCalls]: true });
+		await updateConfig(testDocumentUri, { [Config.completeFunctionCalls]: true });
 
 		// Complete with-in word
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`function abcdef(x, y, z) { }`,
 			`abcdef$0`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`function abcdef(x, y, z) { }`,
 				`abcdef(x, y, z)`
@@ -219,16 +191,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test.skip('completeFunctionCalls should complete function parameters when within word', async () => {
-		await updateConfig({ [Config.completeFunctionCalls]: true });
+		await updateConfig(testDocumentUri, { [Config.completeFunctionCalls]: true });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`function abcdef(x, y, z) { }`,
 			`abcd$0ef`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`function abcdef(x, y, z) { }`,
 				`abcdef(x, y, z)`
@@ -236,16 +207,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('completeFunctionCalls should not complete function parameters at end of word if we are already in something that looks like a function call, #18131', async () => {
-		await updateConfig({ [Config.completeFunctionCalls]: true });
+		await updateConfig(testDocumentUri, { [Config.completeFunctionCalls]: true });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`function abcdef(x, y, z) { }`,
 			`abcdef$0(1, 2, 3)`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`function abcdef(x, y, z) { }`,
 				`abcdef(1, 2, 3)`
@@ -253,16 +223,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test.skip('completeFunctionCalls should not complete function parameters within word if we are already in something that looks like a function call, #18131', async () => {
-		await updateConfig({ [Config.completeFunctionCalls]: true });
+		await updateConfig(testDocumentUri, { [Config.completeFunctionCalls]: true });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`function abcdef(x, y, z) { }`,
 			`abcd$0ef(1, 2, 3)`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`function abcdef(x, y, z) { }`,
 				`abcdef(1, 2, 3)`
@@ -271,7 +240,7 @@ suite('TypeScript Completions', () => {
 
 	test('should not de-prioritize `this.member` suggestion, #74164', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  private detail = '';`,
 				`  foo() {`,
@@ -280,9 +249,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  private detail = '';`,
@@ -297,7 +265,7 @@ suite('TypeScript Completions', () => {
 
 	test('Member completions for string property name should insert `this.` and use brackets', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  ['xyz 123'] = 1`,
 				`  foo() {`,
@@ -306,9 +274,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  ['xyz 123'] = 1`,
@@ -323,7 +290,7 @@ suite('TypeScript Completions', () => {
 
 	test('Member completions for string property name already using `this.` should add brackets', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  ['xyz 123'] = 1`,
 				`  foo() {`,
@@ -332,9 +299,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  ['xyz 123'] = 1`,
@@ -348,16 +314,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a completion in word using `insert` mode should insert', async () => {
-		await updateConfig({ [Config.insertMode]: 'insert' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'insert' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`const abc = 123;`,
 			`ab$0c`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`const abc = 123;`,
 				`abcc`
@@ -365,16 +330,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a completion in word using `replace` mode should replace', async () => {
-		await updateConfig({ [Config.insertMode]: 'replace' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'replace' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`const abc = 123;`,
 			`ab$0c`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`const abc = 123;`,
 				`abc`
@@ -382,9 +346,9 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a member completion in word using `insert` mode add `this.` and insert', async () => {
-		await updateConfig({ [Config.insertMode]: 'insert' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'insert' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`class Foo {`,
 			`  abc = 1;`,
 			`  foo() {`,
@@ -393,9 +357,8 @@ suite('TypeScript Completions', () => {
 			`}`,
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`class Foo {`,
 				`  abc = 1;`,
@@ -407,9 +370,9 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a member completion in word using `replace` mode should add `this.` and replace', async () => {
-		await updateConfig({ [Config.insertMode]: 'replace' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'replace' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`class Foo {`,
 			`  abc = 1;`,
 			`  foo() {`,
@@ -418,9 +381,8 @@ suite('TypeScript Completions', () => {
 			`}`,
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`class Foo {`,
 				`  abc = 1;`,
@@ -432,16 +394,15 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting string completion inside string using `insert` mode should insert', async () => {
-		await updateConfig({ [Config.insertMode]: 'insert' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'insert' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`const abc = { 'xy z': 123 }`,
 			`abc["x$0y w"]`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`const abc = { 'xy z': 123 }`,
 				`abc["xy zy w"]`
@@ -450,16 +411,15 @@ suite('TypeScript Completions', () => {
 
 	// Waiting on https://github.com/microsoft/TypeScript/issues/35602
 	test.skip('Accepting string completion inside string using insert mode should insert', async () => {
-		await updateConfig({ [Config.insertMode]: 'replace' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'replace' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`const abc = { 'xy z': 123 }`,
 			`abc["x$0y w"]`
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`const abc = { 'xy z': 123 }`,
 				`abc["xy w"]`
@@ -468,7 +428,7 @@ suite('TypeScript Completions', () => {
 
 	test('Private field completions on `this.#` should work', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  #xyz = 1;`,
 				`  foo() {`,
@@ -477,9 +437,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  #xyz = 1;`,
@@ -494,7 +453,7 @@ suite('TypeScript Completions', () => {
 
 	test('Private field completions on `#` should insert `this.`', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  #xyz = 1;`,
 				`  foo() {`,
@@ -503,9 +462,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  #xyz = 1;`,
@@ -520,7 +478,7 @@ suite('TypeScript Completions', () => {
 
 	test('Private field completions should not require strict prefix match (#89556)', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  #xyz = 1;`,
 				`  foo() {`,
@@ -529,9 +487,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  #xyz = 1;`,
@@ -546,7 +503,7 @@ suite('TypeScript Completions', () => {
 
 	test('Private field completions without `this.` should not require strict prefix match (#89556)', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  #xyz = 1;`,
 				`  foo() {`,
@@ -555,9 +512,8 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  #xyz = 1;`,
@@ -571,9 +527,9 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a completion for async property in `insert` mode should insert and add await', async () => {
-		await updateConfig({ [Config.insertMode]: 'insert' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'insert' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`class A {`,
 			`  xyz = Promise.resolve({ 'abc': 1 });`,
 			`  async foo() {`,
@@ -582,9 +538,8 @@ suite('TypeScript Completions', () => {
 			`}`,
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`class A {`,
 				`  xyz = Promise.resolve({ 'abc': 1 });`,
@@ -596,9 +551,9 @@ suite('TypeScript Completions', () => {
 	});
 
 	test('Accepting a completion for async property in `replace` mode should replace and add await', async () => {
-		await updateConfig({ [Config.insertMode]: 'replace' });
+		await updateConfig(testDocumentUri, { [Config.insertMode]: 'replace' });
 
-		await createTestEditor(testDocumentUri,
+		const editor = await createTestEditor(testDocumentUri,
 			`class A {`,
 			`  xyz = Promise.resolve({ 'abc': 1 });`,
 			`  async foo() {`,
@@ -607,9 +562,8 @@ suite('TypeScript Completions', () => {
 			`}`,
 		);
 
-		const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-		assert.strictEqual(
-			document.getText(),
+		await acceptFirstSuggestion(testDocumentUri, _disposables);
+		assertEditorContents(editor,
 			joinLines(
 				`class A {`,
 				`  xyz = Promise.resolve({ 'abc': 1 });`,
@@ -622,7 +576,7 @@ suite('TypeScript Completions', () => {
 
 	test.skip('Accepting a completion for async string property should add await plus brackets', async () => {
 		await enumerateConfig(Config.insertMode, insertModes, async config => {
-			await createTestEditor(testDocumentUri,
+			const editor = await createTestEditor(testDocumentUri,
 				`class A {`,
 				`  xyz = Promise.resolve({ 'ab c': 1 });`,
 				`  async foo() {`,
@@ -631,9 +585,9 @@ suite('TypeScript Completions', () => {
 				`}`,
 			);
 
-			const document = await acceptFirstSuggestion(testDocumentUri, _disposables);
-			assert.strictEqual(
-				document.getText(),
+			await acceptFirstSuggestion(testDocumentUri, _disposables);
+
+			assertEditorContents(editor,
 				joinLines(
 					`class A {`,
 					`  xyz = Promise.resolve({ 'abc': 1 });`,
@@ -650,7 +604,7 @@ suite('TypeScript Completions', () => {
 async function enumerateConfig(configKey: string, values: readonly string[], f: (message: string) => Promise<void>): Promise<void> {
 	for (const value of values) {
 		const newConfig = { [configKey]: value };
-		await updateConfig(newConfig);
+		await updateConfig(testDocumentUri, newConfig);
 		await f(JSON.stringify(newConfig));
 	}
 }
diff --git a/extensions/typescript-language-features/src/test/jsDocCompletions.test.ts b/extensions/typescript-language-features/src/test/jsDocCompletions.test.ts
index e0f67065b0a..f9c6c39da88 100644
--- a/extensions/typescript-language-features/src/test/jsDocCompletions.test.ts
+++ b/extensions/typescript-language-features/src/test/jsDocCompletions.test.ts
@@ -7,20 +7,34 @@ import * as assert from 'assert';
 import 'mocha';
 import * as vscode from 'vscode';
 import { disposeAll } from '../utils/dispose';
-import { createTestEditor, joinLines, wait } from './testUtils';
 import { acceptFirstSuggestion } from './suggestTestHelpers';
+import { Config, createTestEditor, joinLines, updateConfig, VsCodeConfiguration, wait } from './testUtils';
 
 const testDocumentUri = vscode.Uri.parse('untitled:test.ts');
 
 suite('JSDoc Completions', () => {
 	const _disposables: vscode.Disposable[] = [];
 
+	const configDefaults: VsCodeConfiguration = Object.freeze({
+		[Config.snippetSuggestions]: 'inline',
+	});
+
+	let oldConfig: { [key: string]: any } = {};
+
 	setup(async () => {
 		await wait(100);
+
+		// Save off config and apply defaults
+		oldConfig = await updateConfig(testDocumentUri, configDefaults);
 	});
 
 	teardown(async () => {
 		disposeAll(_disposables);
+
+		// Restore config
+		await updateConfig(testDocumentUri, oldConfig);
+
+		return vscode.commands.executeCommand('workbench.action.closeAllEditors');
 	});
 
 	test('Should complete jsdoc inside single line comment', async () => {
diff --git a/extensions/typescript-language-features/src/test/testUtils.ts b/extensions/typescript-language-features/src/test/testUtils.ts
index 753814a99bd..e0b4ac867e2 100644
--- a/extensions/typescript-language-features/src/test/testUtils.ts
+++ b/extensions/typescript-language-features/src/test/testUtils.ts
@@ -3,10 +3,11 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import * as vscode from 'vscode';
+import * as assert from 'assert';
 import * as fs from 'fs';
 import * as os from 'os';
 import { join } from 'path';
+import * as vscode from 'vscode';
 
 function rndName() {
 	return Math.random().toString(36).replace(/[^a-z]+/g, '').substr(0, 10);
@@ -80,4 +81,50 @@ export async function createTestEditor(uri: vscode.Uri, ...lines: string[]) {
 	}
 
 	await activeEditor.insertSnippet(new vscode.SnippetString(joinLines(...lines)), new vscode.Range(0, 0, 1000, 0));
+	return activeEditor;
 }
+
+export function assertEditorContents(editor: vscode.TextEditor, expectedDocContent: string, message?: string): void {
+	const cursorIndex = expectedDocContent.indexOf(CURSOR);
+
+	assert.strictEqual(
+		editor.document.getText(),
+		expectedDocContent.replace(CURSOR, ''),
+		message);
+
+	if (cursorIndex >= 0) {
+		const expectedCursorPos = editor.document.positionAt(cursorIndex);
+		assert.strictEqual(
+			editor.selection.active.line,
+			expectedCursorPos.line
+		);
+		assert.strictEqual(
+			editor.selection.active.character,
+			expectedCursorPos.character
+		);
+
+	}
+}
+
+export type VsCodeConfiguration = { [key: string]: any };
+
+export async function updateConfig(documentUri: vscode.Uri, newConfig: VsCodeConfiguration): Promise<VsCodeConfiguration> {
+	const oldConfig: VsCodeConfiguration = {};
+	const config = vscode.workspace.getConfiguration(undefined, documentUri);
+	for (const configKey of Object.keys(newConfig)) {
+		oldConfig[configKey] = config.get(configKey);
+		await new Promise((resolve, reject) =>
+			config.update(configKey, newConfig[configKey], vscode.ConfigurationTarget.Global)
+				.then(() => resolve(), reject));
+	}
+	return oldConfig;
+}
+
+
+export const Config = Object.freeze({
+	autoClosingBrackets: 'editor.autoClosingBrackets',
+	completeFunctionCalls: 'typescript.suggest.completeFunctionCalls',
+	insertMode: 'editor.suggest.insertMode',
+	snippetSuggestions: 'editor.snippetSuggestions',
+	suggestSelection: 'editor.suggestSelection',
+} as const);