test: setup test-helpers package

package.json

@@ -26,6 +26,7 @@
     "eslint-config-prettier": "^9.0.0",
     "jest": "^29.7.0",
     "jest-environment-node": "^29.7.0",
+    "jest-util": "^29.7.0",
     "nx": "19.8.0",
     "prettier": "^2.6.2",
     "ts-jest": "^29.1.0",

test-helpers/README.md

@@ -0,0 +1,11 @@
+# test-helpers
+
+This library was generated with [Nx](https://nx.dev).
+
+## Building
+
+Run `nx build test-helpers` to build the library.
+
+## Running unit tests
+
+Run `nx test test-helpers` to execute the unit tests via [Jest](https://jestjs.io).

test-helpers/eslint.config.js

@@ -0,0 +1,21 @@
+const baseConfig = require('../eslint.config.js');
+
+module.exports = [
+  ...baseConfig,
+  {
+    files: ['**/*.json'],
+    rules: {
+      '@nx/dependency-checks': [
+        'error',
+        {
+          ignoredFiles: ['{projectRoot}/eslint.config.{js,cjs,mjs}'],
+          // TODO: @nx/dependency-checks incorrectly reports unused dependencies
+          checkObsoleteDependencies: false,
+        },
+      ],
+    },
+    languageOptions: {
+      parser: require('jsonc-eslint-parser'),
+    },
+  },
+];

test-helpers/jest.config.ts

@@ -0,0 +1,10 @@
+export default {
+  displayName: 'test-helpers',
+  preset: '../jest.preset.js',
+  testEnvironment: 'node',
+  transform: {
+    '^.+\\.[tj]s$': ['ts-jest', { tsconfig: '<rootDir>/tsconfig.spec.json' }],
+  },
+  moduleFileExtensions: ['ts', 'js', 'html'],
+  coverageDirectory: '../coverage/test-helpers',
+};

test-helpers/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "test-helpers",
+  "version": "0.0.1",
+  "dependencies": {
+    "tslib": "^2.3.0"
+  },
+  "type": "commonjs",
+  "main": "./src/index.js",
+  "typings": "./src/index.d.ts",
+  "private": true
+}

test-helpers/project.json

@@ -0,0 +1,19 @@
+{
+  "name": "test-helpers",
+  "$schema": "../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "test-helpers/src",
+  "projectType": "library",
+  "tags": [],
+  "targets": {
+    "build": {
+      "executor": "@nx/js:tsc",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "outputPath": "dist/test-helpers",
+        "main": "test-helpers/src/index.ts",
+        "tsConfig": "test-helpers/tsconfig.lib.json",
+        "assets": ["test-helpers/*.md"]
+      }
+    }
+  }
+}

test-helpers/src/index.ts

@@ -0,0 +1 @@
+export * from './lib/test-helpers';

test-helpers/src/lib/test-helpers.spec.ts

@@ -0,0 +1,24 @@
+import { writeFiles, getTempDirectory, cleanup } from './test-helpers';
+import * as fs from 'fs';
+import * as path from 'path';
+
+test('writeFiles in temp directory with cleanup', () => {
+  const directory = getTempDirectory('test_helpers');
+  const files = {
+    'package.json': '{}',
+    'dir/file.js': 'module.exports = "x";',
+  };
+
+  writeFiles(directory, files);
+
+  expect(fs.readFileSync(path.join(directory, 'package.json'), 'utf8')).toBe(
+    '{}'
+  );
+  expect(fs.readFileSync(path.join(directory, 'dir', 'file.js'), 'utf8')).toBe(
+    'module.exports = "x";'
+  );
+
+  cleanup(directory);
+
+  expect(fs.existsSync(directory)).toBe(false);
+});

test-helpers/src/lib/test-helpers.ts

@@ -0,0 +1,40 @@
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import * as os from 'node:os';
+import { createDirectory } from 'jest-util';
+
+export const getTempDirectory = (name: string) =>
+  path.resolve(os.tmpdir(), name);
+
+export const cleanup = (directory: string) => {
+  fs.rmSync(directory, { recursive: true, force: true, maxRetries: 10 });
+};
+
+/**
+ * Creates a nested directory with files and their contents
+ * writeFiles(
+ *   '/home/tmp',
+ *   {
+ *     'package.json': '{}',
+ *     'dir/file.js': 'module.exports = "x";',
+ *   }
+ * );
+ */
+export const writeFiles = (
+  directory: string,
+  files: { [filename: string]: string | NodeJS.ArrayBufferView }
+) => {
+  createDirectory(directory);
+
+  Object.keys(files).forEach((fileOrPath) => {
+    const dirname = path.dirname(fileOrPath);
+
+    if (dirname !== '/') {
+      createDirectory(path.join(directory, dirname));
+    }
+    fs.writeFileSync(
+      path.resolve(directory, ...fileOrPath.split('/')),
+      files[fileOrPath]
+    );
+  });
+};

test-helpers/tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "extends": "../tsconfig.base.json",
+  "compilerOptions": {
+    "module": "commonjs",
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "noImplicitOverride": true,
+    "noPropertyAccessFromIndexSignature": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "files": [],
+  "include": [],
+  "references": [
+    {
+      "path": "./tsconfig.lib.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
+  ]
+}

test-helpers/tsconfig.lib.json

@@ -0,0 +1,10 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../dist/out-tsc",
+    "declaration": true,
+    "types": ["node"]
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["jest.config.ts", "src/**/*.spec.ts", "src/**/*.test.ts"]
+}

test-helpers/tsconfig.spec.json

@@ -0,0 +1,14 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../dist/out-tsc",
+    "module": "commonjs",
+    "types": ["jest", "node"]
+  },
+  "include": [
+    "jest.config.ts",
+    "src/**/*.test.ts",
+    "src/**/*.spec.ts",
+    "src/**/*.d.ts"
+  ]
+}

tsconfig.base.json

@@ -15,7 +15,8 @@
     "skipDefaultLibCheck": true,
     "baseUrl": ".",
     "paths": {
-      "@callstack/create-rnef-app": ["packages/create-app/src/index.ts"]
+      "@callstack/create-rnef-app": ["packages/create-app/src/index.ts"],
+      "test-helpers": ["test-helpers/src/index.ts"]
     }
   },
   "exclude": ["node_modules", "tmp"]