Refactor generate-artifacts-executor.js: delete handleLibrariesFromReactNativeConfig (#41654)

Summary:
Pull Request resolved: #41654

This diff removes support for defining external codegen targets in `react-native.config.js` for iOS. Now  you can simply add your external dependency to the project's `package.json` and it will be resolved as a normal Node packages.

## Motivation

The need for defining external codegen targets in `react-native.config.js` historically appeared due to limitations of how codegen searched for external dependencies. Basically we performed search only in the project directory. External dependency paths had to be listed in `react-native.config.js`.

After D51303793 has landed we don't need this any longer. We can simply rely on Node resolution to find those external dependencies.

Changelog: [iOS][Breaking] - Defining external codegen targets in `react-native.config.js` is not supported anymore. Define them as normal dependencies in `package.json`.

Reviewed By: cipolleschi

Differential Revision: D51308595

fbshipit-source-id: 97841a3a8c295aa717c577bb188d48373b04ba38

Author: dmytrorykun

packages/react-native/scripts/codegen/__tests__/generate-artifacts-executor-test.js

@@ -118,76 +118,6 @@ describe('extractLibrariesFromJSON', () => {
   });
 });
 
-describe('findCodegenEnabledLibraries', () => {
-  const mock = require('mock-fs');
-  const {
-    _findCodegenEnabledLibraries: findCodegenEnabledLibraries,
-  } = require('../generate-artifacts-executor');
-
-  afterEach(() => {
-    mock.restore();
-  });
-
-  it('returns libraries defined in react-native.config.js', () => {
-    const projectDir = path.join(__dirname, '../../../../test-project');
-    const baseCodegenConfigFileDir = path.join(__dirname, '../../..');
-    const baseCodegenConfigFilePath = path.join(
-      baseCodegenConfigFileDir,
-      'package.json',
-    );
-
-    mock({
-      [baseCodegenConfigFilePath]: `
-      {
-        "codegenConfig": {}
-      }
-      `,
-      [projectDir]: {
-        app: {
-          'package.json': `{
-            "name": "my-app"
-          }`,
-          'react-native.config.js': '',
-        },
-        'library-foo': {
-          'package.json': `{
-            "name": "react-native-foo",
-            "codegenConfig": {
-              "name": "RNFooSpec",
-              "type": "modules",
-              "jsSrcsDir": "src"
-            }
-          }`,
-        },
-      },
-    });
-
-    jest.mock(path.join(projectDir, 'app', 'react-native.config.js'), () => ({
-      dependencies: {
-        'react-native-foo': {
-          root: path.join(projectDir, 'library-foo'),
-        },
-        'react-native-bar': {
-          root: path.join(projectDir, 'library-bar'),
-        },
-      },
-    }));
-
-    const libraries = findCodegenEnabledLibraries(`${projectDir}/app`);
-
-    expect(libraries).toEqual([
-      {
-        config: {},
-        libraryPath: baseCodegenConfigFileDir,
-      },
-      {
-        config: {name: 'RNFooSpec', type: 'modules', jsSrcsDir: 'src'},
-        libraryPath: path.join(projectDir, 'library-foo'),
-      },
-    ]);
-  });
-});
-
 describe('delete empty files and folders', () => {
   beforeEach(() => {
     jest.resetModules();

packages/react-native/scripts/codegen/generate-artifacts-executor.js

@@ -180,48 +180,6 @@ function handleThirdPartyLibraries(pkgJson) {
   });
 }
 
-function handleLibrariesFromReactNativeConfig(appRootDir) {
-  const rnConfigFileName = 'react-native.config.js';
-
-  console.log(
-    `\n\n[Codegen] >>>>> Searching for codegen-enabled libraries in ${rnConfigFileName}`,
-  );
-
-  const rnConfigFilePath = path.resolve(appRootDir, rnConfigFileName);
-
-  if (!fs.existsSync(rnConfigFilePath)) {
-    return [];
-  }
-  const rnConfig = require(rnConfigFilePath);
-
-  if (rnConfig.dependencies == null) {
-    return [];
-  }
-  return Object.keys(rnConfig.dependencies).flatMap(name => {
-    const dependencyConfig = rnConfig.dependencies[name];
-
-    if (!dependencyConfig.root) {
-      return [];
-    }
-    const codegenConfigFileDir = path.resolve(
-      appRootDir,
-      dependencyConfig.root,
-    );
-    let configFile;
-    try {
-      configFile = readPkgJsonInDirectory(codegenConfigFileDir);
-    } catch {
-      return [];
-    }
-
-    return extractLibrariesFromJSON(
-      configFile,
-      configFile.name,
-      codegenConfigFileDir,
-    );
-  });
-}
-
 function handleInAppLibraries(pkgJson, appRootDir) {
   console.log(
     '\n\n[Codegen] >>>>> Searching for codegen-enabled libraries in the app',
@@ -343,7 +301,6 @@ function findCodegenEnabledLibraries(appRootDir) {
   return [
     ...handleReactNativeCoreLibraries(),
     ...handleThirdPartyLibraries(pkgJson),
-    ...handleLibrariesFromReactNativeConfig(appRootDir),
     ...handleInAppLibraries(pkgJson, appRootDir),
   ];
 }
@@ -434,7 +391,5 @@ module.exports = {
   execute: execute,
   // exported for testing purposes only:
   _extractLibrariesFromJSON: extractLibrariesFromJSON,
-  _findCodegenEnabledLibraries: findCodegenEnabledLibraries,
-  _generateCode: generateCode,
   _cleanupEmptyFilesAndFolders: cleanupEmptyFilesAndFolders,
 };