diff --git a/extensions/typescript/src/features/hoverProvider.ts b/extensions/typescript/src/features/hoverProvider.ts
index b3adf9716e4d69ce696ef08b1343fe6cbadc9077..f1d4c3ae0c595fb115fc3597214dc0804b5f7318 100644
--- a/extensions/typescript/src/features/hoverProvider.ts
+++ b/extensions/typescript/src/features/hoverProvider.ts
@@ -12,18 +12,14 @@ import { ITypescriptServiceClient } from '../typescriptService';
 
 export default class TypeScriptHoverProvider implements HoverProvider {
 
-	private client: ITypescriptServiceClient;
-
-	public constructor(client: ITypescriptServiceClient) {
-		this.client = client;
-	}
+	public constructor(private client: ITypescriptServiceClient) { }
 
 	public provideHover(document: TextDocument, position: Position, token: CancellationToken): Promise<Hover | undefined | null> {
 		const filepath = this.client.normalizePath(document.uri);
 		if (!filepath) {
 			return Promise.resolve(null);
 		}
-		let args: Proto.FileLocationRequestArgs = {
+		const args: Proto.FileLocationRequestArgs = {
 			file: filepath,
 			line: position.line + 1,
 			offset: position.character + 1
@@ -32,8 +28,8 @@ export default class TypeScriptHoverProvider implements HoverProvider {
 			return Promise.resolve(null);
 		}
 		return this.client.execute('quickinfo', args, token).then((response): Hover | undefined => {
-			let data = response.body;
-			if (data) {
+			if (response && response.body) {
+				const data = response.body;
 				return new Hover(
 					[{ language: 'typescript', value: data.displayString }, data.documentation],
 					new Range(data.start.line - 1, data.start.offset - 1, data.end.line - 1, data.end.offset - 1));
diff --git a/extensions/typescript/src/features/referencesCodeLensProvider.ts b/extensions/typescript/src/features/referencesCodeLensProvider.ts
index 561e2a03d5f4256d7b6b00e801f4439aa89c2bd1..8862eb56e5166c72f265ddbe6f6b4cf7abafb54f 100644
--- a/extensions/typescript/src/features/referencesCodeLensProvider.ts
+++ b/extensions/typescript/src/features/referencesCodeLensProvider.ts
@@ -12,17 +12,16 @@ import * as PConst from '../protocol.const';
 import { ITypescriptServiceClient } from '../typescriptService';
 
 import * as nls from 'vscode-nls';
-let localize = nls.loadMessageBundle();
+const localize = nls.loadMessageBundle();
 
 
 class ReferencesCodeLens extends CodeLens {
-	public document: Uri;
-	public file: string;
-
-	constructor(document: Uri, file: string, range: Range) {
+	constructor(
+		public tsDocument: Uri,
+		public tsFile: string,
+		range: Range
+	) {
 		super(range);
-		this.document = document;
-		this.file = file;
 	}
 }
 
@@ -31,14 +30,14 @@ export default class TypeScriptReferencesCodeLensProvider implements CodeLensPro
 
 	private onDidChangeCodeLensesEmitter = new EventEmitter<CodeLensProvider>();
 
+	public constructor(private client: ITypescriptServiceClient) { }
+
 	public get onDidChangeCodeLenses(): Event<CodeLensProvider> {
 		return this.onDidChangeCodeLensesEmitter.event;
 	}
 
-	constructor(private client: ITypescriptServiceClient) { }
-
 	public updateConfiguration(config: WorkspaceConfiguration): void {
-		let typeScriptConfig = workspace.getConfiguration('typescript');
+		const typeScriptConfig = workspace.getConfiguration('typescript');
 		const wasEnabled = this.enabled;
 		this.enabled = typeScriptConfig.get('referencesCodeLens.enabled', false);
 		if (wasEnabled !== this.enabled) {
@@ -56,22 +55,25 @@ export default class TypeScriptReferencesCodeLensProvider implements CodeLensPro
 			return Promise.resolve([]);
 		}
 		return this.client.execute('navtree', { file: filepath }, token).then(response => {
+			if (!response) {
+				return [];
+			}
 			const tree = response.body;
 			const referenceableSpans: Range[] = [];
 			if (tree && tree.childItems) {
 				tree.childItems.forEach(item => this.extractReferenceableSymbols(document, item, referenceableSpans));
 			}
-			return Promise.resolve(referenceableSpans.map(span => new ReferencesCodeLens(document.uri, filepath, span)));
+			return referenceableSpans.map(span => new ReferencesCodeLens(document.uri, filepath, span));
 		});
 	}
 
 	resolveCodeLens(inputCodeLens: CodeLens, token: CancellationToken): Promise<CodeLens> {
 		const codeLens = inputCodeLens as ReferencesCodeLens;
-		if (!codeLens.document) {
+		if (!codeLens.tsDocument) {
 			return Promise.reject<CodeLens>(codeLens);
 		}
 		const args: Proto.FileLocationRequestArgs = {
-			file: codeLens.file,
+			file: codeLens.tsFile,
 			line: codeLens.range.start.line + 1,
 			offset: codeLens.range.start.character + 1
 		};
@@ -90,7 +92,7 @@ export default class TypeScriptReferencesCodeLensProvider implements CodeLensPro
 				codeLens.command = {
 					title: locations.length + ' ' + (locations.length === 1 ? localize('oneReferenceLabel', 'reference') : localize('manyReferenceLabel', 'references')),
 					command: 'editor.action.showReferences',
-					arguments: [codeLens.document, codeLens.range.start, locations]
+					arguments: [codeLens.tsDocument, codeLens.range.start, locations]
 				};
 				return Promise.resolve(codeLens);
 			}