Merge from vscode 2cd495805cf99b31b6926f08ff4348124b2cf73d

extensions/github-browser/src/gate.ts

@@ -0,0 +1,87 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+const emptyStr = '';
+
+function defaultResolver(...args: any[]): string {
+	if (args.length === 1) {
+		const arg0 = args[0];
+		if (arg0 === undefined || arg0 === null) {
+			return emptyStr;
+		}
+		if (typeof arg0 === 'string') {
+			return arg0;
+		}
+		if (typeof arg0 === 'number' || typeof arg0 === 'boolean') {
+			return String(arg0);
+		}
+
+		return JSON.stringify(arg0);
+	}
+
+	return JSON.stringify(args);
+}
+
+function iPromise<T>(obj: T | Promise<T>): obj is Promise<T> {
+	return typeof (obj as Promise<T>)?.then === 'function';
+}
+
+export function gate<T extends (...arg: any) => any>(resolver?: (...args: Parameters<T>) => string) {
+	return (_target: any, key: string, descriptor: PropertyDescriptor) => {
+		let fn: Function | undefined;
+		if (typeof descriptor.value === 'function') {
+			fn = descriptor.value;
+		} else if (typeof descriptor.get === 'function') {
+			fn = descriptor.get;
+		}
+		if (fn === undefined || fn === null) {
+			throw new Error('Not supported');
+		}
+
+		const gateKey = `$gate$${key}`;
+
+		descriptor.value = function (this: any, ...args: any[]) {
+			const prop =
+				args.length === 0 ? gateKey : `${gateKey}$${(resolver ?? defaultResolver)(...(args as Parameters<T>))}`;
+
+			if (!Object.prototype.hasOwnProperty.call(this, prop)) {
+				Object.defineProperty(this, prop, {
+					configurable: false,
+					enumerable: false,
+					writable: true,
+					value: undefined,
+				});
+			}
+
+			let promise = this[prop];
+			if (promise === undefined) {
+				let result;
+				try {
+					result = fn!.apply(this, args);
+					if (result === undefined || fn === null || !iPromise(result)) {
+						return result;
+					}
+
+					this[prop] = promise = result
+						.then((r: any) => {
+							this[prop] = undefined;
+							return r;
+						})
+						.catch(ex => {
+							this[prop] = undefined;
+							throw ex;
+						});
+				} catch (ex) {
+					this[prop] = undefined;
+					throw ex;
+				}
+			}
+
+			return promise;
+		};
+	};
+}