Split package "flipper-pkg" into two: lib and cli

Summary: "flipper-pkg" added ~2MB to Flipper disttributive size, because of heavy dependencies which are only required for CLI functionality. See size warning in diff D21068373 in this stack where I added pkg as dependency to flipper. Here I'm splitting it into library and CLI packages, so Flipper app will only reference the library.

Reviewed By: passy

Differential Revision: D21087336

fbshipit-source-id: d9d62f1e75a835d1c0fa78ff1addb0d9a761a9c7

desktop/pkg-lib/src/runBuild.ts

@@ -0,0 +1,68 @@
+/**
+ * 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 Metro from 'metro';
+import getWatchFolders from './getWatchFolders';
+
+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,
+) {
+  const baseConfig = await Metro.loadConfig();
+  const config = Object.assign({}, baseConfig, {
+    reporter: {update: () => {}},
+    projectRoot: inputDirectory,
+    watchFolders: [inputDirectory, ...(await getWatchFolders(inputDirectory))],
+    serializer: {
+      ...baseConfig.serializer,
+      getRunModuleStatement: (moduleID: string) =>
+        `module.exports = global.__r(${moduleID}).default;`,
+      createModuleIdFactory,
+    },
+    transformer: {
+      ...baseConfig.transformer,
+      babelTransformerPath: require.resolve('flipper-babel-transformer'),
+    },
+  });
+  await Metro.runBuild(config, {
+    dev: false,
+    minify: false,
+    resetCache: false,
+    sourceMap: true,
+    entry,
+    out,
+  });
+}