packager: add basic top-level integration test

Summary: I'd like us to start having some decent testing at the packager/bundler level to check that there are no major breakage hapenning. This changeset introduce a simple test that just test the `buildBundle` public API. On the same model, I'd like to test the server API and behavior, and things such as hot module reloading. I hope this will also highlight the gross inconsistencies of the API, for example the Bundle/BundleBase hierarchy, that we can proceed to fix later.

Reviewed By: davidaurelio, cpojer

Differential Revision: D5121817

fbshipit-source-id: e0f3758c7fbb7a85cf51fb3cbc34c12d5374b7d3

packages/metro-bundler/index.js

@@ -54,6 +54,8 @@ type PublicBundleOptions = {
   +sourceMapUrl?: string,
 };
 
+exports.TransformCaching = TransformCaching;
+
 /**
  * This is a public API, so we don't trust the value and purposefully downgrade
  * it as `mixed`. Because it understands `invariant`, Flow ensure that we

packages/metro-bundler/integration_tests/__tests__/basic_bundle-test.js

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @format
+ */
+
+'use strict';
+
+jest.disableAutomock();
+jest.useRealTimers();
+
+const Packager = require('../..');
+
+const path = require('path');
+
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 30 * 1000;
+
+const INPUT_PATH = path.resolve(__dirname, '../basic_bundle');
+const POLYFILLS_PATH = path.resolve(__dirname, '../../src/Resolver/polyfills');
+
+describe('basic_bundle', () => {
+  it('bundles package as expected', async () => {
+    const bundle = await Packager.buildBundle(
+      {
+        projectRoots: [INPUT_PATH, POLYFILLS_PATH],
+        transformCache: Packager.TransformCaching.none(),
+        transformModulePath: require.resolve('../../transformer'),
+      },
+      {
+        dev: false,
+        entryFile: path.join(INPUT_PATH, 'TestBundle.js'),
+        platform: 'ios',
+      },
+    );
+    const absPathRe = new RegExp(INPUT_PATH, 'g');
+    expect(bundle.getSource().replace(absPathRe, '')).toMatchSnapshot();
+  });
+});

packages/metro-bundler/integration_tests/basic_bundle/Bar.js

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @format
+ */
+
+'use strict';
+
+const Foo = require('./Foo');
+
+module.exports = {type: 'bar', foo: Foo.type};

packages/metro-bundler/integration_tests/basic_bundle/Foo.js

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @format
+ */
+
+'use strict';
+
+const asset = require('./test.png');
+
+module.exports = {type: 'foo', asset};

packages/metro-bundler/integration_tests/basic_bundle/TestBundle.js

@@ -0,0 +1,17 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @format
+ */
+
+'use strict';
+
+const Bar = require('./Bar');
+const Foo = require('./Foo');
+
+module.exports = {Foo, Bar};