Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/src/vs/base/test/common/cache.test.ts

@@ -0,0 +1,65 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import { Cache } from 'vs/base/common/cache';
+import { timeout } from 'vs/base/common/async';
+
+suite('Cache', () => {
+
+	test('simple value', () => {
+		let counter = 0;
+		const cache = new Cache(_ => Promise.resolve(counter++));
+
+		return cache.get().promise
+			.then(c => assert.equal(c, 0), () => assert.fail('Unexpected assertion error'))
+			.then(() => cache.get().promise)
+			.then(c => assert.equal(c, 0), () => assert.fail('Unexpected assertion error'));
+	});
+
+	test('simple error', () => {
+		let counter = 0;
+		const cache = new Cache(_ => Promise.reject(new Error(String(counter++))));
+
+		return cache.get().promise
+			.then(() => assert.fail('Unexpected assertion error'), err => assert.equal(err.message, 0))
+			.then(() => cache.get().promise)
+			.then(() => assert.fail('Unexpected assertion error'), err => assert.equal(err.message, 0));
+	});
+
+	test('should retry cancellations', () => {
+		let counter1 = 0, counter2 = 0;
+
+		const cache = new Cache(token => {
+			counter1++;
+			return Promise.resolve(timeout(2, token).then(() => counter2++));
+		});
+
+		assert.equal(counter1, 0);
+		assert.equal(counter2, 0);
+		let result = cache.get();
+		assert.equal(counter1, 1);
+		assert.equal(counter2, 0);
+		result.promise.then(undefined, () => assert(true));
+		result.dispose();
+		assert.equal(counter1, 1);
+		assert.equal(counter2, 0);
+
+		result = cache.get();
+		assert.equal(counter1, 2);
+		assert.equal(counter2, 0);
+
+		return result.promise
+			.then(c => {
+				assert.equal(counter1, 2);
+				assert.equal(counter2, 1);
+			})
+			.then(() => cache.get().promise)
+			.then(c => {
+				assert.equal(counter1, 2);
+				assert.equal(counter2, 1);
+			});
+	});
+});