Add relay-config library

.flowconfig

@@ -3,6 +3,7 @@
 <PROJECT_ROOT>/compiler/.*
 <PROJECT_ROOT>/.*/node_modules/.*
 .*/node_modules/resolve/test/resolver/malformed_package_json/package.json
+<PROJECT_ROOT>/.*/__tests__/.*/package.json
 
 [options]
 module.system=haste

gulpfile.js

@@ -36,7 +36,9 @@ const babel = require('gulp-babel');
 const header = require('gulp-header');
 const rename = require('gulp-rename');
 const gulpUtil = require('gulp-util');
+const jsonSchemaToTypescript = require('json-schema-to-typescript');
 const path = require('path');
+const stream = require('stream');
 const webpack = require('webpack');
 const webpackStream = require('webpack-stream');
 
@@ -211,8 +213,63 @@ const builds = [
       },
     ],
   },
+  {
+    package: 'relay-config',
+    exports: {
+      index: 'index.js',
+    },
+    bundles: [
+      {
+        entry: 'index.js',
+        output: 'relay-config',
+        libraryName: 'RelayConfig',
+        libraryTarget: 'commonjs2',
+        target: 'node',
+        noMinify: true, // Note: uglify can't yet handle modern JS
+      },
+    ],
+  },
 ];
 
+const relayConfig = gulp.parallel(
+  function copyCompilerConfigSchema() {
+    return gulp
+      .src(['relay-compiler-config-schema.json'], {
+        cwd: path.join('compiler/crates/relay-compiler'),
+      })
+      .pipe(gulp.dest(path.join(DIST, 'relay-config')));
+  },
+  function copyTypescriptTypes() {
+    return gulp
+      .src(['index.d.ts'], {
+        cwd: path.join(PACKAGES, 'relay-config'),
+      })
+      .pipe(gulp.dest(path.join(DIST, 'relay-config')));
+  },
+  function generateConfigTypescriptTypes() {
+    return gulp
+      .src(['relay-compiler-config-schema.json'], {
+        cwd: path.join('compiler/crates/relay-compiler'),
+      })
+      .pipe(
+        new stream.Transform({
+          objectMode: true,
+          transform(file, _, callback) {
+            jsonSchemaToTypescript
+              .compile(JSON.parse(file.contents.toString()))
+              .then(data => {
+                file.contents = Buffer.from(data);
+                callback(null, file);
+              })
+              .catch(error => callback(error, null));
+          },
+        }),
+      )
+      .pipe(rename('RelayConfig.d.ts'))
+      .pipe(gulp.dest(path.join(DIST, 'relay-config')));
+  },
+);
+
 const modules = gulp.parallel(
   ...builds.map(
     build =>
@@ -225,6 +282,7 @@ const modules = gulp.parallel(
           .pipe(gulp.dest(path.join(DIST, build.package, 'lib')));
       },
   ),
+  relayConfig,
 );
 
 const flowDefs = gulp.parallel(

package.json

@@ -37,6 +37,7 @@
     "@babel/traverse": "^7.14.0",
     "@babel/types": "^7.0.0",
     "@jest/create-cache-key-function": "^29.7.0",
+    "@rushstack/node-core-library": "^5.8.0",
     "babel-eslint": "^10.1.0",
     "babel-plugin-macros": "^2.0.0",
     "babel-plugin-syntax-hermes-parser": "0.23.1",
@@ -47,6 +48,7 @@
     "del": "6.0.0",
     "eslint": "^8.57.0",
     "eslint-config-fbjs": "4.0.0",
+    "json-schema-to-typescript": "^13.0.0",
     "eslint-plugin-babel": "5.3.1",
     "eslint-plugin-ft-flow": "2.0.1",
     "eslint-plugin-import": "^2.26.0",

packages/relay-config/README.md

@@ -0,0 +1,3 @@
+# relay-config
+
+A utility library for loading and saving Relay compiler config files.

packages/relay-config/__tests__/fixtures/invalid-config/package.json

@@ -0,0 +1,5 @@
+{
+    "name": "my-app",
+    "version": "1.0.0",
+    "relay": {}
+}

packages/relay-config/__tests__/fixtures/js-config/package.json

@@ -0,0 +1,4 @@
+{
+    "name": "my-app",
+    "version": "1.0.0"
+}

packages/relay-config/__tests__/fixtures/js-config/relay.config.js

@@ -0,0 +1 @@
+module.exports = {language: 'typescript', schema: 'schema.graphql'};

packages/relay-config/__tests__/fixtures/json-config/package.json

@@ -0,0 +1,4 @@
+{
+    "name": "my-app",
+    "version": "1.0.0"
+}

packages/relay-config/__tests__/fixtures/json-config/relay.config.json

@@ -0,0 +1,4 @@
+{
+    "language": "typescript",
+    "schema": "schema.graphql"
+}

packages/relay-config/__tests__/fixtures/no-config/package.json

@@ -0,0 +1,4 @@
+{
+    "name": "my-app",
+    "version": "1.0.0"
+}

packages/relay-config/__tests__/fixtures/package-json-config/package.json

@@ -0,0 +1,8 @@
+{
+    "name": "my-app",
+    "version": "1.0.0",
+    "relay": {
+        "language": "typescript",
+        "schema": "schema.graphql"
+    }
+}

packages/relay-config/__tests__/loadConfig-test.js

@@ -0,0 +1,52 @@
+/**
+ * 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.
+ *
+ * @flow
+ * @format
+ * @oncall relay
+ */
+
+'use strict';
+
+const loadConfig = require('../loadConfig');
+const path = require('path');
+
+describe('loadConfig', () => {
+  it('Returns undefined if there is no config available', () => {
+    expect(
+      loadConfig(path.join(__dirname, 'fixtures/no-config')),
+    ).toBeUndefined();
+  });
+
+  it('Fails if the config is invalid', () => {
+    expect(() =>
+      loadConfig(path.join(__dirname, 'fixtures/invalid-config')),
+    ).toThrow();
+  });
+
+  it('Properly loads relay.config.js files', () => {
+    expect(loadConfig(path.join(__dirname, 'fixtures/js-config'))).toEqual({
+      language: 'typescript',
+      schema: 'schema.graphql',
+    });
+  });
+
+  it('Properly loads relay.config.json files', () => {
+    expect(loadConfig(path.join(__dirname, 'fixtures/json-config'))).toEqual({
+      language: 'typescript',
+      schema: 'schema.graphql',
+    });
+  });
+
+  it('Properly loads package.json config', () => {
+    expect(
+      loadConfig(path.join(__dirname, 'fixtures/package-json-config')),
+    ).toEqual({
+      language: 'typescript',
+      schema: 'schema.graphql',
+    });
+  });
+});

packages/relay-config/index.d.ts

@@ -0,0 +1,21 @@
+/**
+ * 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
+ * @oncall relay
+ */
+
+import { ConfigFile as RelayConfig } from './RelayConfig';
+
+declare function loadConfig(): Promise<RelayConfig>;
+
+declare function saveConfig(
+  config: RelayConfig,
+  folder: string,
+  configType: 'relay.config.js' | 'relay.config.json' | 'package.json',
+): Promise<void>;
+
+export { loadConfig, saveConfig, RelayConfig };

packages/relay-config/index.js

@@ -0,0 +1,16 @@
+/**
+ * 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.
+ *
+ * @flow
+ * @format
+ * @oncall relay
+ */
+
+'use strict';
+
+const loadConfig = require('./loadConfig');
+
+module.exports = {loadConfig};

packages/relay-config/loadConfig.js

@@ -0,0 +1,32 @@
+/**
+ * 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.
+ *
+ * @flow
+ * @format
+ * @oncall relay
+ */
+
+'use strict';
+
+const loadSchema = require('./loadSchema');
+const cosmiconfig = require('cosmiconfig');
+
+function loadConfig(folder?: string): any | void {
+  const schema = loadSchema();
+
+  const result = cosmiconfig('relay', {
+    searchPlaces: ['relay.config.js', 'relay.config.json', 'package.json'],
+  }).searchSync(folder);
+  if (!result) {
+    return;
+  }
+  const {config, filepath} = result;
+
+  schema.validateObject(config, filepath);
+  return config;
+}
+
+module.exports = loadConfig;

packages/relay-config/loadSchema.js

@@ -0,0 +1,35 @@
+/**
+ * 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.
+ *
+ * @flow
+ * @format
+ * @oncall relay
+ */
+
+'use strict';
+
+const {JsonSchema} = require('@rushstack/node-core-library');
+const path = require('path');
+
+function loadSchema(): any {
+  return JsonSchema.fromFile(
+    path.join(__dirname, 'relay-compiler-config-schema.json'),
+    {
+      customFormats: {
+        uint8: {
+          type: 'number',
+          validate: data => data >= 0 && data <= 255,
+        },
+        uint: {
+          type: 'number',
+          validate: data => data >= 0 && data <= Number.MAX_SAFE_INTEGER,
+        },
+      },
+    },
+  );
+}
+
+module.exports = loadSchema;

packages/relay-config/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "relay-config",
+  "description": "A utility library for loading and saving Relay compiler config files.",
+  "version": "17.0.0",
+  "keywords": [
+    "graphql",
+    "relay"
+  ],
+  "license": "MIT",
+  "homepage": "https://relay.dev",
+  "bugs": "https://github.com/facebook/relay/issues",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/facebook/relay.git",
+    "directory": "packages/relay-config"
+  },
+  "dependencies": {
+    "@rushstack/node-core-library": "^5.8.0",
+    "cosmiconfig": "^5.0.5"
+  },
+  "directories": {
+    "": "./"
+  },
+  "main": "index.js",
+  "types": "index.d.ts"
+}