feat(testing): support root project generation for jest

docs/generated/packages/jest.json

@@ -41,6 +41,12 @@
             "type": "boolean",
             "default": false,
             "description": "Use JavaScript instead of TypeScript for config files"
+          },
+          "rootProject": {
+            "description": "initialize Jest for an application at the root of the workspace",
+            "type": "boolean",
+            "default": false,
+            "hidden": true
           }
         },
         "required": [],
@@ -123,6 +129,12 @@
             "type": "boolean",
             "default": false,
             "description": "Use JavaScript instead of TypeScript for config files"
+          },
+          "rootProject": {
+            "description": "Add Jest to an application at the root of the workspace",
+            "type": "boolean",
+            "default": false,
+            "hidden": true
           }
         },
         "required": [],

packages/jest/index.ts

@@ -5,4 +5,7 @@ export {
 export { jestConfigObjectAst } from './src/utils/config/functions';
 export { jestProjectGenerator } from './src/generators/jest-project/jest-project';
 export { jestInitGenerator } from './src/generators/init/init';
-export { getJestProjects } from './src/utils/config/get-jest-projects';
+export {
+  getJestProjects,
+  getNestedJestProjects,
+} from './src/utils/config/get-jest-projects';

packages/jest/src/generators/init/init.spec.ts

@@ -1,6 +1,8 @@
 import {
+  addProjectConfiguration,
   NxJsonConfiguration,
   readJson,
+  readProjectConfiguration,
   stripIndents,
   Tree,
   updateJson,
@@ -41,9 +43,16 @@ describe('jest', () => {
   });
 
   it('should not override existing files', async () => {
-    tree.write('jest.config.ts', `test`);
+    const expected = stripIndents`
+import { getJestProjects } from '@nrwl/jest';
+export default {
+  projects: getJestProjects(),
+  extraThing: "Goes Here"
+}
+`;
+    tree.write('jest.config.ts', expected);
     jestInitGenerator(tree, {});
-    expect(tree.read('jest.config.ts', 'utf-8')).toEqual('test');
+    expect(tree.read('jest.config.ts', 'utf-8')).toEqual(expected);
   });
 
   it('should add target defaults for test', async () => {
@@ -144,6 +153,90 @@ describe('jest', () => {
     });
   });
 
+  describe('root project', () => {
+    it('should not add a monorepo jest.config.ts  to the project', () => {
+      jestInitGenerator(tree, { rootProject: true });
+      expect(tree.exists('jest.config.ts')).toBeFalsy();
+    });
+
+    it('should rename the project jest.config.ts to project jest config', () => {
+      tree.write('nx.json', JSON.stringify({ defaultProject: 'my-project' }));
+      addProjectConfiguration(tree, 'my-project', {
+        root: '',
+        name: 'my-project',
+        sourceRoot: 'src',
+        targets: {
+          test: {
+            executor: '@nrwl/jest:jest',
+            options: {
+              jestConfig: 'jest.config.ts',
+            },
+          },
+        },
+      });
+      tree.write(
+        'jest.config.ts',
+        `
+/* eslint-disable */
+export default {
+  transform: {
+    '^.+\\.[tj]sx?$': 'ts-jest',
+  },
+  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'html'],
+  globals: { 'ts-jest': { tsconfig: '<rootDir>/tsconfig.spec.json' } },
+  displayName: 'my-project',
+  testEnvironment: 'node',
+  preset: '../../jest.preset.js',
+};
+`
+      );
+      jestInitGenerator(tree, { rootProject: false });
+      expect(tree.exists('jest.my-project.config.ts')).toBeTruthy();
+      expect(tree.read('jest.config.ts', 'utf-8'))
+        .toEqual(`import { getJestProjects } from '@nrwl/jest';
+
+export default {
+projects: getJestProjects()
+};`);
+      expect(readProjectConfiguration(tree, 'my-project').targets.test)
+        .toMatchInlineSnapshot(`
+        Object {
+          "executor": "@nrwl/jest:jest",
+          "options": Object {
+            "jestConfig": "jest.my-project.config.ts",
+          },
+        }
+      `);
+    });
+
+    it('should work with --js', () => {
+      tree.write(
+        'jest.config.js',
+        `
+/* eslint-disable */
+module.exports = {
+  transform: {
+    '^.+\\.[tj]sx?$': 'ts-jest',
+  },
+  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'html'],
+  globals: { 'ts-jest': { tsconfig: '<rootDir>/tsconfig.spec.json' } },
+  displayName: 'my-project',
+  testEnvironment: 'node',
+  preset: '../../jest.preset.js',
+};
+`
+      );
+      jestInitGenerator(tree, { js: true, rootProject: false });
+      expect(tree.exists('jest.project-config.js')).toBeTruthy();
+      expect(tree.read('jest.config.js', 'utf-8'))
+        .toEqual(`const { getJestProjects } = require('@nrwl/jest');
+
+module.exports = {
+projects: getJestProjects()
+};`);
+    });
+  });
+
   describe('adds jest extension', () => {
     beforeEach(async () => {
       writeJson(tree, '.vscode/extensions.json', {

packages/jest/src/generators/init/init.ts

@@ -8,7 +8,11 @@ import {
   Tree,
   updateJson,
   updateWorkspaceConfiguration,
+  readProjectConfiguration,
+  readJson,
+  updateProjectConfiguration,
 } from '@nrwl/devkit';
+import { findRootJestConfig } from '../../utils/config/find-root-jest-files';
 import {
   babelJestVersion,
   jestTypesVersion,
@@ -20,18 +24,71 @@ import {
   tsNodeVersion,
 } from '../../utils/versions';
 import { JestInitSchema } from './schema';
+import { extname } from 'path';
 
 interface NormalizedSchema extends ReturnType<typeof normalizeOptions> {}
 
 const schemaDefaults = {
   compiler: 'tsc',
   js: false,
+  rootProject: false,
 } as const;
 
-function createJestConfig(tree: Tree, js: boolean = false) {
+function createJestConfig(tree: Tree, options: NormalizedSchema) {
+  if (!tree.exists('jest.preset.js')) {
+    // preset is always js file.
+    tree.write(
+      `jest.preset.js`,
+      `
+      const nxPreset = require('@nrwl/jest/preset').default;
+     
+      module.exports = { ...nxPreset }`
+    );
+
+    addTestInputs(tree);
+  }
+  const rootJestConfig = findRootJestConfig(tree);
+
+  if (options.rootProject && !rootJestConfig) {
+    // we don't want any config to be made because the jest-project generator
+    // will make the config when using rootProject
+    return;
+  }
+  const isProjectConfig =
+    rootJestConfig &&
+    tree.exists(rootJestConfig) &&
+    !tree.read(rootJestConfig, 'utf-8').includes('getJestProjects()');
+  if (!options.rootProject && isProjectConfig) {
+    // moving from single project to multi project.
+    // TODO(caleb): this is brittle and needs to be detected better?
+    const nxJson = readJson(tree, 'nx.json');
+    const defaultProject =
+      nxJson.cli?.defaultProjectName || nxJson?.defaultProject;
+
+    const ext = extname(rootJestConfig);
+    const newJestConfigPath = defaultProject
+      ? `jest.${defaultProject}.config${ext}`
+      : `jest.project-config${ext}`;
+
+    tree.rename(rootJestConfig, newJestConfigPath);
+
+    if (defaultProject) {
+      const projectConfig = readProjectConfiguration(tree, defaultProject);
+
+      // TODO(caleb): do we care about a custom target name?
+      if (projectConfig?.targets?.['test']?.options?.jestConfig) {
+        projectConfig.targets['test'].options.jestConfig = newJestConfigPath;
+        updateProjectConfiguration(tree, defaultProject, projectConfig);
+      }
+    } else {
+      console.warn(stripIndents`Could not find the default project project.json to update the test target options.
+Manually update the 'jestConfig' path to point to ${newJestConfigPath}`);
+    }
+  }
+
   // if the root ts config already exists then don't make a js one or vice versa
   if (!tree.exists('jest.config.ts') && !tree.exists('jest.config.js')) {
-    const contents = js
+    const contents = options.js
       ? stripIndents`
       const { getJestProjects } = require('@nrwl/jest');
 
@@ -44,20 +101,7 @@ function createJestConfig(tree: Tree, js: boolean = false) {
       export default {
        projects: getJestProjects()
       };`;
-    tree.write(`jest.config.${js ? 'js' : 'ts'}`, contents);
-  }
-
-  if (!tree.exists('jest.preset.js')) {
-    // preset is always js file.
-    tree.write(
-      `jest.preset.js`,
-      `
-      const nxPreset = require('@nrwl/jest/preset').default;
-     
-      module.exports = { ...nxPreset }`
-    );
-
-    addTestInputs(tree);
+    tree.write(`jest.config.${options.js ? 'js' : 'ts'}`, contents);
   }
 }
 
@@ -144,7 +188,7 @@ function updateExtensions(host: Tree) {
 
 export function jestInitGenerator(tree: Tree, schema: JestInitSchema) {
   const options = normalizeOptions(schema);
-  createJestConfig(tree, options.js);
+  createJestConfig(tree, options);
 
   let installTask: GeneratorCallback = () => {};
   if (!options.skipPackageJson) {

packages/jest/src/generators/init/schema.d.ts

@@ -6,4 +6,5 @@ export interface JestInitSchema {
    * @deprecated
    */
   babelJest?: boolean;
+  rootProject?: boolean;
 }

packages/jest/src/generators/init/schema.json

@@ -21,6 +21,12 @@
       "type": "boolean",
       "default": false,
       "description": "Use JavaScript instead of TypeScript for config files"
+    },
+    "rootProject": {
+      "description": "initialize Jest for an application at the root of the workspace",
+      "type": "boolean",
+      "default": false,
+      "hidden": true
     }
   },
   "required": []

packages/jest/src/generators/jest-project/jest-project.spec.ts

@@ -362,4 +362,73 @@ describe('jestProject', () => {
       expect(tree.read('libs/lib1/jest.config.ts', 'utf-8')).toMatchSnapshot();
     });
   });
+
+  describe('root project', () => {
+    it('root jest.config.ts should be project config', async () => {
+      writeJson(tree, 'tsconfig.json', {
+        files: [],
+        include: [],
+        references: [],
+      });
+      addProjectConfiguration(tree, 'my-project', {
+        root: '',
+        sourceRoot: 'src',
+        name: 'my-project',
+        targets: {},
+      });
+      await jestProjectGenerator(tree, {
+        ...defaultOptions,
+        project: 'my-project',
+        rootProject: true,
+      });
+      expect(tree.read('jest.config.ts', 'utf-8')).toMatchInlineSnapshot(`
+        "/* eslint-disable */
+        export default {
+          displayName: 'my-project',
+          preset: '../jest.preset.js',
+          globals: {
+            'ts-jest': {
+              tsconfig: '<rootDir>/tsconfig.spec.json',
+            }
+          },
+          coverageDirectory: '../coverage/'
+        };
+        "
+      `);
+    });
+
+    it('root jest.config.js should be project config', async () => {
+      writeJson(tree, 'tsconfig.json', {
+        files: [],
+        include: [],
+        references: [],
+      });
+      addProjectConfiguration(tree, 'my-project', {
+        root: '',
+        sourceRoot: 'src',
+        name: 'my-project',
+        targets: {},
+      });
+      await jestProjectGenerator(tree, {
+        ...defaultOptions,
+        project: 'my-project',
+        rootProject: true,
+        js: true,
+      });
+      expect(tree.read('jest.config.js', 'utf-8')).toMatchInlineSnapshot(`
+        "/* eslint-disable */
+        module.exports = {
+          displayName: 'my-project',
+          preset: '../jest.preset.js',
+          globals: {
+            'ts-jest': {
+              tsconfig: '<rootDir>/tsconfig.spec.json',
+            }
+          },
+          coverageDirectory: '../coverage/'
+        };
+        "
+      `);
+    });
+  });
 });

packages/jest/src/generators/jest-project/jest-project.ts

@@ -13,6 +13,7 @@ const schemaDefaults = {
   supportTsx: false,
   skipSetupFile: false,
   skipSerializers: false,
+  rootProject: false,
 } as const;
 
 function normalizeOptions(options: JestProjectSchema) {
@@ -42,7 +43,7 @@ function normalizeOptions(options: JestProjectSchema) {
 
   // setupFile is always 'none'
   options.setupFile = schemaDefaults.setupFile;
-
+  options.rootProject = options.rootProject;
   return {
     ...schemaDefaults,
     ...options,
@@ -59,7 +60,11 @@ export async function jestProjectGenerator(
   createFiles(tree, options);
   updateTsConfig(tree, options);
   updateWorkspace(tree, options);
-  updateJestConfig(tree, options);
+  // TODO(caleb): is this really needed anymore?
+  // surely everyone is on the getJestProjects() fn usage already?
+  // should remove it and provide a migration (just in case) so we can remove it
+  // which makes the root project work simpler
+  // updateJestConfig(tree, options);
   if (!schema.skipFormat) {
     await formatFiles(tree);
   }