Make react-native.config.js be appended to existing file.

local-cli/generator-common/index.js

@@ -125,6 +125,21 @@ function upgradeFileContentChangedCallback(
   );
 }
 
+/**
+ * @param {string} srcPath
+ * @param {string} relativeDestDir
+ * @param {Record<string, string>} replacements
+ */
+function appendToExistingFile(srcPath, relativeDestDir, replacements) {
+  walk(srcPath).forEach(absoluteSrcFilePath => {
+    const filename = path.relative(srcPath, absoluteSrcFilePath);
+    const relativeDestPath = path.join(relativeDestDir, replaceInPath(filename, replacements));
+
+    const templateFileContents = fs.readFileSync(absoluteSrcFilePath, { encoding: 'UTF8' });
+    fs.appendFileSync(relativeDestPath, templateFileContents);
+  });
+}
+
 module.exports = {
-  createDir, copyAndReplaceWithChangedCallback, copyAndReplaceAll,
+  appendToExistingFile, createDir, copyAndReplaceWithChangedCallback, copyAndReplaceAll,
 };

local-cli/generator-macos/index.js

@@ -7,6 +7,7 @@ const path = require('path');
 const childProcess = require('child_process');
 const fs = require('fs');
 const {
+  appendToExistingFile,
   createDir,
   copyAndReplaceAll,
   copyAndReplaceWithChangedCallback,
@@ -60,6 +61,9 @@ function copyProjectTemplateAndReplace(
 
   [
     { from: path.join(srcRootPath, 'react-native.config.js'), to: 'react-native.config.js' },
+  ].forEach((mapping) => appendToExistingFile(mapping.from, mapping.to, templateVars));
+
+  [
     { from: path.join(srcRootPath, 'metro.config.macos.js'), to: 'metro.config.macos.js' },
   ].forEach((mapping) => copyAndReplaceWithChangedCallback(mapping.from, destPath, mapping.to, templateVars, options.overwrite));
 

local-cli/generator-macos/templates/react-native.config.js

@@ -1,33 +1,9 @@
-/**
- * This cli config is needed for the coexistance of react-native and other
- * out-of-tree implementations such react-native-macos.
- * The following issue is tracked by
- * https://github.com/react-native-community/discussions-and-proposals/issues/182
- *
- * The work-around involves having a metro.config.js for each out-of-tree
- * platform, i.e. metro.config.js for react-native and
- * metro.config.macos.js for react-native-macos.
- * This react-native.config.js looks for a --use-react-native-macos
- * switch and when present pushes --config=metro.config.macos.js
- * and specifies reactNativePath: 'node_modules/react-native-macos'.
- * The metro.config.js has to blacklist 'node_modules/react-native-macos',
- * and conversely metro.config.macos.js has to blacklist 'node_modules/react-native'.
- */
-'use strict';
-
 const macSwitch = '--use-react-native-macos';
-const windowsSwitch = '--use-react-native-windows';
 
 if (process.argv.includes(macSwitch)) {
   process.argv = process.argv.filter(arg => arg !== macSwitch);
   process.argv.push('--config=metro.config.macos.js');
   module.exports = {
     reactNativePath: 'node_modules/react-native-macos',
   };
-} else if (process.argv.includes(windowsSwitch)) {
-  process.argv = process.argv.filter(arg => arg !== windowsSwitch);
-  process.argv.push('--config=metro.config.windows.js');
-  module.exports = {
-    reactNativePath: 'node_modules/react-native-windows',
-  };
 }