Move desktop-related code to "desktop" subfolder (#872)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/872
Move all the JS code related to desktop app to "desktop" subfolder.

The structure of "desktop" folder:
- `src` - JS code of Flipper desktop app executing in Electron Renderer (Chrome) process. This folder also contains all the Flipper plugins in subfolder "src/plugins".
- `static` - JS code of Flipper desktop app bootstrapping executing in Electron Main (Node.js) process
- `pkg` - Flipper packaging lib and CLI tool
- `doctor` - Flipper diagnostics lib and CLI tool
- `scripts` - Build scripts for Flipper desktop app
- `headless` - Headless version of Flipper app
- `headless-tests` - Integration tests running agains Flipper headless version

Reviewed By: passy

Differential Revision: D20249304

fbshipit-source-id: 9a51c63b51b92b758a02fc8ebf7d3d116770efe9

desktop/pkg/src/utils/runBuild.ts

@@ -0,0 +1,72 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const Metro = require('metro'); // no typings :(
+import * as path from 'path';
+
+function hash(string: string) {
+  let hash = 0;
+  if (string.length === 0) {
+    return hash;
+  }
+  let chr;
+  for (let i = 0; i < string.length; i++) {
+    chr = string.charCodeAt(i);
+    hash = (hash << 5) - hash + chr;
+    hash |= 0;
+  }
+  return hash;
+}
+const fileToIdMap = new Map();
+const createModuleIdFactory = () => (filePath: string) => {
+  if (filePath === '__prelude__') {
+    return 0;
+  }
+  let id = fileToIdMap.get(filePath);
+  if (typeof id !== 'number') {
+    id = hash(filePath);
+    fileToIdMap.set(filePath, id);
+  }
+  return id;
+};
+
+export default async function runBuild(
+  inputDirectory: string,
+  entry: string,
+  out: string,
+) {
+  await Metro.runBuild(
+    {
+      reporter: {update: () => {}},
+      projectRoot: inputDirectory,
+      watchFolders: [inputDirectory, path.resolve(__dirname, '..', '..')],
+      serializer: {
+        getRunModuleStatement: (moduleID: string) =>
+          `module.exports = global.__r(${moduleID}).default;`,
+        createModuleIdFactory,
+      },
+      transformer: {
+        babelTransformerPath: path.resolve(
+          __dirname,
+          '..',
+          'transforms',
+          'index.js',
+        ),
+      },
+    },
+    {
+      dev: false,
+      minify: false,
+      resetCache: true,
+      sourceMap: true,
+      entry,
+      out,
+    },
+  );
+}

desktop/pkg/src/utils/yarn.ts

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import * as util from 'util';
+import {exec as execImport} from 'child_process';
+const exec = util.promisify(execImport);
+
+const WINDOWS = /^win/.test(process.platform);
+const YARN_PATH = 'yarn' + (WINDOWS ? '.cmd' : '');
+
+export async function install(pkgDir: string) {
+  const {stderr} = await exec(YARN_PATH, {
+    cwd: pkgDir,
+  });
+  if (stderr) {
+    console.warn(stderr);
+  }
+}
+
+export async function pack(pkgDir: string, out: string) {
+  const {stderr} = await exec(
+    [YARN_PATH, 'pack', '--filename', out].join(' '),
+    {
+      cwd: pkgDir,
+    },
+  );
+  if (stderr) {
+    console.warn(stderr);
+  }
+}