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/flipper-requires.js

@@ -0,0 +1,81 @@
+/**
+ * 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 {resolve, dirname} = require('path');
+
+// do not apply this transform for these paths
+const EXCLUDE_PATHS = [
+  '/node_modules/react-devtools-core/',
+  'relay-devtools/DevtoolsUI',
+];
+
+function isExcludedPath(path) {
+  for (const epath of EXCLUDE_PATHS) {
+    if (path.indexOf(epath) > -1) {
+      return true;
+    }
+  }
+  return false;
+} // $FlowFixMe
+module.exports = ({types: t}) => ({
+  visitor: {
+    // $FlowFixMe
+    CallExpression(path, state) {
+      if (isExcludedPath(state.file.opts.filename)) {
+        return;
+      }
+      const node = path.node;
+      const args = node.arguments || [];
+
+      if (
+        node.callee.name === 'require' &&
+        args.length === 1 &&
+        t.isStringLiteral(args[0])
+      ) {
+        if (args[0].value === 'flipper') {
+          path.replaceWith(t.identifier('global.Flipper'));
+        } else if (args[0].value === 'react') {
+          path.replaceWith(t.identifier('global.React'));
+        } else if (args[0].value === 'react-dom') {
+          path.replaceWith(t.identifier('global.ReactDOM'));
+        } else if (args[0].value === 'adbkit') {
+          path.replaceWith(t.identifier('global.adbkit'));
+        } else if (
+          // require a file not a pacakge
+          args[0].value.indexOf('/') > -1 &&
+          // in the plugin itself and not inside one of its dependencies
+          state.file.opts.filename.indexOf('node_modules') === -1 &&
+          // the resolved path for this file is outside the plugins root
+          !resolve(dirname(state.file.opts.filename), args[0].value).startsWith(
+            state.file.opts.root,
+          ) &&
+          !resolve(dirname(state.file.opts.filename), args[0].value).indexOf(
+            '/static/',
+          ) < 0
+        ) {
+          throw new Error(
+            `Plugins cannot require files from outside their folder. Attempted to require ${resolve(
+              dirname(state.file.opts.filename),
+              args[0].value,
+            )} which isn't inside ${state.file.opts.root}`,
+          );
+        }
+      }
+    },
+    Identifier(path, state) {
+      if (
+        path.node.name === 'React' &&
+        path.parentPath.node.id !== path.node &&
+        !isExcludedPath(state.file.opts.filename)
+      ) {
+        path.replaceWith(t.identifier('global.React'));
+      }
+    },
+  },
+});