Refactor generate-specs-cli and add tests

Summary:
This Diff splits the `generate-specs-cli.js` script into:
* `generate-specs-cli-executor.js`: which contains the logic to generate the code for iOS.
* `generate-specs-cli.js`: which contains the argument parsing logic and invokes the executor.

Finally it introduces some tests.

## Changelog
[iOS][Changed] - Refactor part of the codegen scripts and add tests.

Differential Revision: https://www.internalfb.com/diff/D35892576?entry_point=27

fbshipit-source-id: 8a94f9ee7fafe8e3e7ba980b5d78dd87c0d6e4a3

scripts/codegen/__test_fixtures__/fixtures.js

@@ -0,0 +1,87 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @emails oncall+react_native
+ * @format
+ */
+
+'use-strict';
+
+const SCHEMA_TEXT = `
+    {
+  "modules": {
+    "ColoredView": {
+      "type": "Component",
+      "components": {
+        "ColoredView": {
+          "extendsProps": [
+            {
+              "type": "ReactNativeBuiltInType",
+              "knownTypeName": "ReactNativeCoreViewProps"
+            }
+          ],
+          "events": [],
+          "props": [
+            {
+              "name": "color",
+              "optional": false,
+              "typeAnnotation": {
+                "type": "StringTypeAnnotation",
+                "default": null
+              }
+            }
+          ],
+          "commands": []
+        }
+      }
+    },
+    "NativeCalculator": {
+      "type": "NativeModule",
+      "aliases": {},
+      "spec": {
+        "properties": [
+          {
+            "name": "add",
+            "optional": false,
+            "typeAnnotation": {
+              "type": "FunctionTypeAnnotation",
+              "returnTypeAnnotation": {
+                "type": "PromiseTypeAnnotation"
+              },
+              "params": [
+                {
+                  "name": "a",
+                  "optional": false,
+                  "typeAnnotation": {
+                    "type": "NumberTypeAnnotation"
+                  }
+                },
+                {
+                  "name": "b",
+                  "optional": false,
+                  "typeAnnotation": {
+                    "type": "NumberTypeAnnotation"
+                  }
+                }
+              ]
+            }
+          }
+        ]
+      },
+      "moduleNames": [
+        "Calculator"
+      ]
+    }
+  }
+}
+`;
+
+const SCHEMA = JSON.parse(SCHEMA_TEXT);
+
+module.exports = {
+  schemaText: SCHEMA_TEXT,
+  schema: SCHEMA,
+};

scripts/codegen/__tests__/generate-specs-cli-executor-test.js

@@ -0,0 +1,90 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @emails oncall+react_native
+ * @format
+ */
+
+'use strict';
+
+const sut = require('../generate-specs-cli-executor');
+const fixtures = require('../__test_fixtures__/fixtures');
+
+describe('generateSpec', () => {
+  it('invokes RNCodegen with the right params', () => {
+    const platform = 'ios';
+    const libraryType = 'all';
+    const schemaPath = './';
+    const componentsOutputDir =
+      'app/ios/build/generated/ios/react/renderer/components/library';
+    const modulesOutputDir = 'app/ios/build/generated/ios/./library';
+    const outputDirectory = 'app/ios/build/generated/ios';
+    const libraryName = 'library';
+    const packageName = 'com.library';
+    const generators = ['componentsIOS', 'modulesIOS'];
+
+    jest.mock('fs', () => ({
+      readFileSync: (path, encoding) => {
+        expect(path).toBe(schemaPath);
+        expect(encoding).toBe('utf-8');
+        return fixtures.schemaText;
+      },
+    }));
+
+    let mkdirpSyncInvoked = 0;
+    jest.mock('mkdirp', () => ({
+      sync: folder => {
+        if (mkdirpSyncInvoked === 0) {
+          expect(folder).toBe(componentsOutputDir);
+        }
+
+        if (mkdirpSyncInvoked === 1) {
+          expect(folder).toBe(modulesOutputDir);
+        }
+
+        if (mkdirpSyncInvoked === 2) {
+          expect(folder).toBe(outputDirectory);
+        }
+
+        mkdirpSyncInvoked += 1;
+      },
+    }));
+
+    // We cannot mock directly the `RNCodegen` object because the
+    // code access the `lib` folder directly and request a file explicitly.
+    // This makes testing harder than usually. To overcome this, we created a utility
+    // to retrieve the `Codegen`. By doing that, we can mock the wrapper so that it returns
+    // an object with the same interface of the `RNCodegen` object.
+    jest.mock('../codegen-utils', () => ({
+      getCodegen: () => ({
+        generate: (libraryConfig, generatorConfigs) => {
+          expect(libraryConfig.libraryName).toBe(libraryName);
+          expect(libraryConfig.schema).toStrictEqual(fixtures.schema);
+          expect(libraryConfig.outputDirectory).toBe(outputDirectory);
+          expect(libraryConfig.packageName).toBe(packageName);
+          expect(libraryConfig.componentsOutputDir).toBe(componentsOutputDir);
+          expect(libraryConfig.modulesOutputDir).toBe(modulesOutputDir);
+
+          expect(generatorConfigs.generators).toStrictEqual(generators);
+          expect(generatorConfigs.test).toBeUndefined();
+        },
+      }),
+    }));
+
+    sut.execute(
+      platform,
+      schemaPath,
+      outputDirectory,
+      libraryName,
+      packageName,
+      libraryType,
+      componentsOutputDir,
+      modulesOutputDir,
+    );
+
+    expect(mkdirpSyncInvoked).toBe(3);
+  });
+});

scripts/codegen/codegen-utils.js

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+'use strict';
+
+/**
+ * Wrapper required to abstract away from the actual codegen.
+ * This is needed because, when running tests in Sandcastle, not everything is setup as usually.
+ * For example, the `react-native-codegen` lib is not present.
+ *
+ * Thanks to this wrapper, we are able to mock the getter for the codegen in a way that allow us to return
+ * a custom object which mimics the Codegen interface.
+ *
+ * @return an object that can generate the code for the New Architecture.
+ */
+function getCodegen() {
+  let RNCodegen;
+  try {
+    RNCodegen = require('../../packages/react-native-codegen/lib/generators/RNCodegen.js');
+  } catch (e) {
+    RNCodegen = require('../react-native-codegen/lib/generators/RNCodegen.js');
+  }
+  if (!RNCodegen) {
+    throw 'RNCodegen not found.';
+  }
+  return RNCodegen;
+}
+
+module.exports = {
+  getCodegen: getCodegen,
+};

scripts/codegen/generate-specs-cli-executor.js

@@ -0,0 +1,127 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+'use strict';
+
+const fs = require('fs');
+const mkdirp = require('mkdirp');
+const path = require('path');
+const utils = require('./codegen-utils');
+const RNCodegen = utils.getCodegen();
+
+const GENERATORS = {
+  all: {
+    android: ['componentsAndroid', 'modulesAndroid'],
+    ios: ['componentsIOS', 'modulesIOS'],
+  },
+  components: {
+    android: ['componentsAndroid'],
+    ios: ['componentsIOS'],
+  },
+  modules: {
+    android: ['modulesAndroid'],
+    ios: ['modulesIOS'],
+  },
+};
+
+function deprecated_createOutputDirectoryIfNeeded(
+  outputDirectory,
+  libraryName,
+) {
+  if (!outputDirectory) {
+    outputDirectory = path.resolve(__dirname, '..', 'Libraries', libraryName);
+  }
+  mkdirp.sync(outputDirectory);
+}
+
+function createFolderIfDefined(folder) {
+  if (folder) {
+    mkdirp.sync(folder);
+  }
+}
+
+/**
+ * This function read a JSON schema from a path and parses it.
+ * It throws if the schema don't exists or it can't be parsed.
+ *
+ * @parameter schemaPath: the path to the schema
+ * @return a valid schema
+ * @throw an Error if the schema doesn't exists in a given path or if it can't be parsed.
+ */
+function readAndParseSchema(schemaPath) {
+  const schemaText = fs.readFileSync(schemaPath, 'utf-8');
+
+  if (schemaText == null) {
+    throw new Error(`Can't find schema at ${schemaPath}`);
+  }
+
+  try {
+    return JSON.parse(schemaText);
+  } catch (err) {
+    throw new Error(`Can't parse schema to JSON. ${schemaPath}`);
+  }
+}
+
+function validateLibraryType(libraryType) {
+  if (GENERATORS[libraryType] == null) {
+    throw new Error(`Invalid library type. ${libraryType}`);
+  }
+}
+
+function generateSpec(
+  platform,
+  schemaPath,
+  outputDirectory,
+  libraryName,
+  packageName,
+  libraryType,
+  componentsOutputDir,
+  modulesOutputDir,
+) {
+  validateLibraryType(libraryType);
+
+  let schema = readAndParseSchema(schemaPath);
+
+  createFolderIfDefined(componentsOutputDir);
+  createFolderIfDefined(modulesOutputDir);
+  deprecated_createOutputDirectoryIfNeeded(outputDirectory, libraryName);
+
+  RNCodegen.generate(
+    {
+      libraryName,
+      schema,
+      outputDirectory,
+      packageName,
+      componentsOutputDir,
+      modulesOutputDir,
+    },
+    {
+      generators: GENERATORS[libraryType][platform],
+    },
+  );
+
+  if (platform === 'android') {
+    // Move all components C++ files to a structured jni folder for now.
+    // Note: this should've been done by RNCodegen's generators, but:
+    // * the generators don't support platform option yet
+    // * this subdir structure is Android-only, not applicable to iOS
+    const files = fs.readdirSync(outputDirectory);
+    const jniOutputDirectory = `${outputDirectory}/jni/react/renderer/components/${libraryName}`;
+    mkdirp.sync(jniOutputDirectory);
+    files
+      .filter(f => f.endsWith('.h') || f.endsWith('.cpp'))
+      .forEach(f => {
+        fs.renameSync(`${outputDirectory}/${f}`, `${jniOutputDirectory}/${f}`);
+      });
+  }
+}
+
+module.exports = {
+  execute: generateSpec,
+};