add hasteFS.getSize e2e test

e2e/__tests__/haste_map_size.test.js

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) 2018-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+'use strict';
+
+import os from 'os';
+import path from 'path';
+import HasteMap from 'jest-haste-map';
+import {cleanup, writeFiles} from '../Utils';
+
+const DIR = path.resolve(os.tmpdir(), 'haste_map_size');
+
+beforeEach(() => {
+  cleanup(DIR);
+  writeFiles(DIR, {
+    'file.js': '"abc"',
+  });
+});
+afterEach(() => cleanup(DIR));
+
+const options = {
+  extensions: ['js'],
+  forceNodeFilesystemAPI: true,
+  ignorePattern: / ^/,
+  maxWorkers: 2,
+  mocksPattern: '',
+  name: 'tmp',
+  platforms: [],
+  retainAllFiles: true,
+  rootDir: DIR,
+  roots: [DIR],
+  useWatchman: false,
+  watch: false,
+};
+
+test('reports the correct file size', async () => {
+  const hasteMap = new HasteMap(options);
+  const hasteFS = (await hasteMap.build()).hasteFS;
+  expect(hasteFS.getSize(path.join(DIR, 'file.js'))).toBe(5);
+});
+
+test('updates the file size when a file changes', async () => {
+  const hasteMap = new HasteMap({...options, watch: true});
+  await hasteMap.build();
+
+  writeFiles(DIR, {
+    'file.js': '"asdf"',
+  });
+  const {hasteFS} = await new Promise(resolve =>
+    hasteMap.once('change', resolve),
+  );
+  hasteMap.end();
+  expect(hasteFS.getSize(path.join(DIR, 'file.js'))).toBe(6);
+});