Add support for Windows in the 0.69 PackageTest project (#448)

* Add back custom metro.config and specify version.

* Add windows support to the PackageTest project, and update windows peerDependencies.

Author: Alex-MSFT

Apps/PackageTest/0.69.0/.gitignore

@@ -61,3 +61,6 @@ buck-out/
 # Ruby / CocoaPods
 /ios/Pods/
 /vendor/bundle/
+
+# Windows
+/msbuild.binlog

Apps/PackageTest/0.69.0/metro.config.js

@@ -4,26 +4,106 @@
  *
  * @format
  */
-const path = require('path');
-const exclusionList = require('metro-config/src/defaults/exclusionList');
-
-module.exports = {
-  resolver: {
-    blockList: exclusionList([
-      // This stops "react-native run-windows" from causing the metro server to crash if its already running
-      new RegExp(
-        `${path.resolve(__dirname, 'windows').replace(/[/\\]/g, '/')}.*`,
-      ),
-      // This prevents "react-native run-windows" from hitting: EBUSY: resource busy or locked, open msbuild.ProjectImports.zip
-      /.*\.ProjectImports\.zip/,
-    ]),
-  },
-  transformer: {
-    getTransformOptions: async () => ({
-      transform: {
-        experimentalImportSupport: false,
-        inlineRequires: true,
-      },
-    }),
-  },
-};
+ const path = require('path');
+ const fs = require('fs');
+ const exclusionList = require('metro-config/src/defaults/exclusionList');
+ 
+ // Escape function taken from the MDN documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Escaping
+ function escapeRegExp(string) {
+   return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
+ }
+ 
+ // NOTE: The Metro bundler does not support symlinks (see https://github.com/facebook/metro/issues/1), which NPM uses for local packages.
+ //       To work around this, we explicity tell the metro bundler where to find local/linked packages.
+ 
+ // Create a mapping of package ids to linked directories.
+ function processModuleSymLinks() {
+   const nodeModulesPath = path.resolve(__dirname, 'node_modules');
+   let moduleMappings = {};
+   let moduleExclusions = [];
+ 
+   function findPackageDirs(directory) {
+     fs.readdirSync(directory).forEach(item => {
+       const itemPath = path.resolve(directory, item);
+       const itemStat = fs.lstatSync(itemPath);
+       if (itemStat.isSymbolicLink()) {
+         let linkPath = fs.readlinkSync(itemPath);
+         // Sym links are relative in Unix, absolute in Windows.
+         if (!path.isAbsolute(linkPath)) {
+           linkPath = path.resolve(directory, linkPath);
+         }
+         const linkStat = fs.statSync(linkPath);
+         if (linkStat.isDirectory()) {
+           const packagePath = path.resolve(linkPath, "package.json");
+           if (fs.existsSync(packagePath)) {
+             const packageId = path.relative(nodeModulesPath, itemPath);
+             moduleMappings[packageId] = linkPath;
+ 
+             const packageInfoData = fs.readFileSync(packagePath);
+             const packageInfo = JSON.parse(packageInfoData);
+ 
+             const dependencies = packageInfo.dependencies ? Object.keys(packageInfo.dependencies) : [];
+             const peerDependencies = packageInfo.peerDependencies ? Object.keys(packageInfo.peerDependencies) : [];
+             const devDependencies = packageInfo.devDependencies ? Object.keys(packageInfo.devDependencies) : [];
+ 
+             // Exclude dependencies that appear in devDependencies or peerDependencies but not in dependencies. Otherwise,
+             // the metro bundler will package those devDependencies/peerDependencies as unintended copies.
+             for (const devDependency of devDependencies.concat(peerDependencies).filter(dependency => !dependencies.includes(dependency))) {
+               moduleExclusions.push(new RegExp(escapeRegExp(path.join(linkPath, "node_modules", devDependency)) + "\/.*"));
+             }
+           }
+         }
+       } else if (itemStat.isDirectory()) {
+         findPackageDirs(itemPath);
+       }
+     });
+   }
+ 
+   findPackageDirs(nodeModulesPath);
+ 
+   return [moduleMappings, moduleExclusions];
+ }
+ 
+ const [moduleMappings, moduleExclusions] = processModuleSymLinks();
+ console.log("Mapping the following sym linked packages:");
+ console.log(moduleMappings);
+ 
+ module.exports = {
+   transformer: {
+     getTransformOptions: async () => ({
+       transform: {
+         experimentalImportSupport: false,
+         inlineRequires: true,
+       },
+     }),
+   },
+ 
+   resolver: {
+     // Register an "extra modules proxy" for resolving modules outside of the normal resolution logic.
+     extraNodeModules: new Proxy(
+       // Provide the set of known local package mappings.
+       moduleMappings,
+       {
+         // Provide a mapper function, which uses the above mappings for associated package ids,
+         // otherwise fall back to the standard behavior and just look in the node_modules directory.
+         get: (target, name) => name in target ? target[name] : path.join(__dirname, `node_modules/${name}`),
+       },
+     ),
+     
+     blockList: exclusionList(moduleExclusions.concat([
+       // Avoid error EBUSY: resource busy or locked, open 'D:\a\1\s\packages\playground\msbuild.ProjectImports.zip' in pipeline
+       /.*\.ProjectImports\.zip/,
+   
+       // This stops "react-native run-windows" from causing the metro server to crash if its already running
+       new RegExp(
+         `${path.resolve(__dirname, 'windows').replace(/[/\\]/g, '/')}.*`,
+       ),
+     ])),
+   },
+ 
+   projectRoot: path.resolve(__dirname),
+ 
+   // Also additionally watch all the mapped local directories for changes to support live updates.
+   watchFolders: Object.values(moduleMappings),
+ };
+