Check cancellation token earlier and avoid capturing resolve (microsoft#166416)

Author: mjbvz

extensions/typescript-language-features/src/languageFeatures/fileConfigurationManager.ts

@@ -77,24 +77,27 @@ export default class FileConfigurationManager extends Disposable {
 		const cachedOptions = this.formatOptions.get(document.uri);
 		if (cachedOptions) {
 			const cachedOptionsValue = await cachedOptions;
+			if (token.isCancellationRequested) {
+				return;
+			}
+
 			if (cachedOptionsValue && areFileConfigurationsEqual(cachedOptionsValue, currentOptions)) {
 				return;
 			}
 		}
 
-		let resolve: (x: FileConfiguration | undefined) => void;
-		this.formatOptions.set(document.uri, new Promise<FileConfiguration | undefined>(r => resolve = r));
+		const task = (async () => {
+			try {
+				const response = await this.client.execute('configure', { file, ...currentOptions }, token);
+				return response.type === 'response' ? currentOptions : undefined;
+			} catch {
+				return undefined;
+			}
+		})();
+
+		this.formatOptions.set(document.uri, task);
 
-		const args: Proto.ConfigureRequestArguments = {
-			file,
-			...currentOptions,
-		};
-		try {
-			const response = await this.client.execute('configure', args, token);
-			resolve!(response.type === 'response' ? currentOptions : undefined);
-		} finally {
-			resolve!(undefined);
-		}
+		await task;
 	}
 
 	public async setGlobalConfigurationFromDocument(