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/static/transforms/index.js

@@ -0,0 +1,157 @@
+/**
+ * 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 generate = require('@babel/generator').default;
+const babylon = require('@babel/parser');
+const babel = require('@babel/core');
+const fs = require('fs');
+const path = require('path');
+const staticDir = path.resolve(__dirname, '..');
+
+function transform({filename, options, src}) {
+  const isPlugin =
+    options.projectRoot && !__dirname.startsWith(options.projectRoot);
+  const isMain =
+    options.projectRoot &&
+    options.projectRoot === staticDir &&
+    !options.isTestRunner;
+  const isTypeScript = filename.endsWith('.tsx') || filename.endsWith('.ts');
+  const presets = [
+    isMain
+      ? [
+          require('../node_modules/@babel/preset-env'),
+          {targets: {electron: require('electron/package.json').version}},
+        ]
+      : require('../node_modules/@babel/preset-react'),
+  ];
+
+  const ast = babylon.parse(src, {
+    filename,
+    plugins: isTypeScript
+      ? [
+          'jsx',
+          'typescript',
+          'classProperties',
+          'optionalChaining',
+          'nullishCoalescingOperator',
+        ]
+      : [
+          'jsx',
+          ['flow', {all: true}],
+          'classProperties',
+          'objectRestSpread',
+          'optionalChaining',
+          'nullishCoalescingOperator',
+        ],
+    sourceType: 'module',
+  });
+
+  // run babel
+  const plugins = [];
+
+  if (!isTypeScript) {
+    plugins.push(
+      require('../node_modules/@babel/plugin-transform-modules-commonjs'),
+      require('../node_modules/@babel/plugin-proposal-object-rest-spread'),
+      require('../node_modules/@babel/plugin-proposal-class-properties'),
+      require('../node_modules/@babel/plugin-transform-flow-strip-types'),
+      require('../node_modules/@babel/plugin-proposal-optional-chaining'),
+      require('../node_modules/@babel/plugin-proposal-nullish-coalescing-operator'),
+      require('./dynamic-requires.js'),
+    );
+  } else {
+    plugins.push(
+      require('../node_modules/@babel/plugin-transform-typescript'),
+      require('../node_modules/@babel/plugin-proposal-class-properties'),
+      require('../node_modules/@babel/plugin-transform-modules-commonjs'),
+      require('../node_modules/@babel/plugin-proposal-optional-chaining'),
+      require('../node_modules/@babel/plugin-proposal-nullish-coalescing-operator'),
+    );
+  }
+
+  if (
+    fs.existsSync(
+      path.resolve(path.dirname(path.dirname(__dirname)), 'src', 'fb'),
+    )
+  ) {
+    plugins.push(require('./fb-stubs.js'));
+  }
+
+  if (process.env.BUILD_HEADLESS) {
+    plugins.push(require('./electron-stubs.js'));
+  }
+  if (!options.isTestRunner) {
+    if (isMain) {
+      // For the main Electron process ("static" folder), to avoid issues with
+      // native node modules, we prevent Metro from resolving any installed modules.
+      // Instead all of them are just resolved from "node_modules" as usual.
+      plugins.push(require('./electron-requires-main'));
+      // Metro bundler messes up "global.process", so we're changing all its occurrences to "global.electronProcess" instead.
+      // https://github.com/facebook/metro/blob/7e6b3114fc4a9b07a8c0dd3797b1e0c55a4c32ad/packages/metro/src/lib/getPreludeCode.js#L24
+      plugins.push(require('./electron-process'));
+    } else {
+      // Replacing require statements with electronRequire to prevent metro from
+      // resolving them. electronRequire are resolved during runtime by electron.
+      // As the tests are not bundled by metro and run in @jest-runner/electron,
+      // electron imports are working out of the box.
+      plugins.push(require('./electron-requires'));
+    }
+  }
+  if (isPlugin) {
+    plugins.push(require('./flipper-requires.js'));
+  } else {
+    plugins.push(require('./import-react.js'));
+  }
+  const transformed = babel.transformFromAst(ast, src, {
+    ast: true,
+    babelrc: !filename.includes('node_modules'),
+    code: false,
+    comments: false,
+    compact: false,
+    root: options.projectRoot,
+    filename,
+    plugins,
+    presets,
+    sourceMaps: true,
+    retainLines: !!options.isTestRunner,
+  });
+
+  const result = generate(
+    transformed.ast,
+    {
+      filename,
+      sourceFileName: filename,
+      sourceMaps: true,
+      retainLines: !!options.isTestRunner,
+    },
+    src,
+  );
+  return {
+    ast: transformed.ast,
+    code: result.code,
+    filename,
+    map: result.map,
+  };
+}
+
+module.exports = {
+  transform,
+  // Disable caching of babel transforms all together. We haven't found a good
+  // way to cache our transforms, as they rely on side effects like env vars or
+  // the existence of folders in the file system.
+  getCacheKey: () => Math.random().toString(36),
+  process(src, filename, config, options) {
+    return transform({
+      src,
+      filename,
+      config,
+      options: {...options, isTestRunner: true},
+    });
+  },
+};