From b02b49ebd0e21295d2cb0aa48dddb661ec53e83a Mon Sep 17 00:00:00 2001
From: Matt Bierner <matb@microsoft.com>
Date: Wed, 21 Feb 2018 18:54:47 -0800
Subject: [PATCH] Use async

---
 .../src/features/signatureHelpProvider.ts     | 75 +++++++++----------
 1 file changed, 35 insertions(+), 40 deletions(-)

diff --git a/extensions/typescript/src/features/signatureHelpProvider.ts b/extensions/typescript/src/features/signatureHelpProvider.ts
index 0768e03f4a6..92a975c8187 100644
--- a/extensions/typescript/src/features/signatureHelpProvider.ts
+++ b/extensions/typescript/src/features/signatureHelpProvider.ts
@@ -13,56 +13,51 @@ import { vsPositionToTsFileLocation } from '../utils/convert';
 export default class TypeScriptSignatureHelpProvider implements SignatureHelpProvider {
 
 	public constructor(
-		private client: ITypeScriptServiceClient) { }
+		private readonly client: ITypeScriptServiceClient
+	) { }
 
-	public provideSignatureHelp(document: TextDocument, position: Position, token: CancellationToken): Promise<SignatureHelp | undefined | null> {
+	public async provideSignatureHelp(document: TextDocument, position: Position, token: CancellationToken): Promise<SignatureHelp | undefined | null> {
 		const filepath = this.client.normalizePath(document.uri);
 		if (!filepath) {
-			return Promise.resolve(null);
+			return null;
 		}
 		const args: Proto.SignatureHelpRequestArgs = vsPositionToTsFileLocation(filepath, position);
-		return this.client.execute('signatureHelp', args, token).then((response) => {
-			const info = response.body;
-			if (!info) {
-				return null;
+
+		const response = await this.client.execute('signatureHelp', args, token);
+		const info = response.body;
+		if (!info) {
+			return null;
+		}
+
+		const result = new SignatureHelp();
+		result.activeSignature = info.selectedItemIndex;
+		result.activeParameter = info.argumentIndex;
+
+		info.items.forEach((item, i) => {
+			// keep active parameter in bounds
+			if (i === info.selectedItemIndex && item.isVariadic) {
+				result.activeParameter = Math.min(info.argumentIndex, item.parameters.length - 1);
 			}
 
-			const result = new SignatureHelp();
-			result.activeSignature = info.selectedItemIndex;
-			result.activeParameter = info.argumentIndex;
+			const signature = new SignatureInformation('');
+			signature.label += Previewer.plain(item.prefixDisplayParts);
 
-			info.items.forEach((item, i) => {
-				if (!info) {
-					return;
+			item.parameters.forEach((p, i, a) => {
+				const parameter = new ParameterInformation(
+					Previewer.plain(p.displayParts),
+					Previewer.plain(p.documentation));
+
+				signature.label += parameter.label;
+				signature.parameters.push(parameter);
+				if (i < a.length - 1) {
+					signature.label += Previewer.plain(item.separatorDisplayParts);
 				}
-
-				// keep active parameter in bounds
-				if (i === info.selectedItemIndex && item.isVariadic) {
-					result.activeParameter = Math.min(info.argumentIndex, item.parameters.length - 1);
-				}
-
-				const signature = new SignatureInformation('');
-				signature.label += Previewer.plain(item.prefixDisplayParts);
-
-				item.parameters.forEach((p, i, a) => {
-					const parameter = new ParameterInformation(
-						Previewer.plain(p.displayParts),
-						Previewer.plain(p.documentation));
-
-					signature.label += parameter.label;
-					signature.parameters.push(parameter);
-					if (i < a.length - 1) {
-						signature.label += Previewer.plain(item.separatorDisplayParts);
-					}
-				});
-				signature.label += Previewer.plain(item.suffixDisplayParts);
-				signature.documentation = Previewer.markdownDocumentation(item.documentation, item.tags);
-				result.signatures.push(signature);
 			});
-
-			return result;
-		}, () => {
-			return null;
+			signature.label += Previewer.plain(item.suffixDisplayParts);
+			signature.documentation = Previewer.markdownDocumentation(item.documentation, item.tags);
+			result.signatures.push(signature);
 		});
+
+		return result;
 	}
 }
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