Angular: Introduce TestBed-based story rendering in @storybook/angular-vite

code/addons/vitest/src/angular-vitest-postinstall.test.ts

@@ -0,0 +1,235 @@
+import { describe, expect, it } from 'vitest';
+
+import type { types as t } from 'storybook/internal/babel';
+import { babelParse, generate, traverse } from 'storybook/internal/babel';
+
+import {
+  ANGULAR_VITEST_IMPORT_SOURCE,
+  ANGULAR_VITEST_PLUGIN_CALL,
+  collectStorybookTestLocalNames,
+  injectAngularVitestIntoAst,
+  injectAngularVitestIntoConfig,
+  isAngularVitestAlreadyWired,
+} from './angular-vitest-postinstall.ts';
+
+/** Returns the names of the elements (call callees / spread) inside the plugins array, in order. */
+function pluginCalleesInSameArray(code: string, locatorName = 'storybookTest'): string[] | null {
+  const ast = babelParse(code);
+  let elements: string[] | null = null;
+  traverse(ast, {
+    CallExpression(path) {
+      if (elements) {
+        path.stop();
+        return;
+      }
+      const { callee } = path.node;
+      if (
+        callee.type === 'Identifier' &&
+        callee.name === locatorName &&
+        path.parentPath.isArrayExpression()
+      ) {
+        const array = path.parentPath.node as t.ArrayExpression;
+        elements = array.elements.map((el) => {
+          if (el?.type === 'CallExpression' && el.callee.type === 'Identifier') {
+            return el.callee.name;
+          }
+          if (el?.type === 'SpreadElement') {
+            return 'spread';
+          }
+          return el?.type ?? 'null';
+        });
+        path.stop();
+      }
+    },
+  });
+  return elements;
+}
+
+function countOccurrences(haystack: string, needle: string): number {
+  return haystack.split(needle).length - 1;
+}
+
+const FRESH_V4 = `
+import path from 'node:path';
+import { defineConfig } from 'vitest/config';
+import { storybookTest } from '@storybook/addon-vitest/vitest-plugin';
+
+export default defineConfig({
+  test: {
+    projects: [
+      {
+        extends: true,
+        plugins: [
+          // The plugin will run tests for the stories defined in your Storybook config
+          storybookTest({ configDir: path.join(__dirname, '.storybook') }),
+        ],
+        test: { name: 'storybook' },
+      },
+    ],
+  },
+});
+`;
+
+describe('isAngularVitestAlreadyWired', () => {
+  it('is false on a plain storybookTest config', () => {
+    expect(isAngularVitestAlreadyWired(FRESH_V4)).toBe(false);
+  });
+
+  it('is true when the import source is present', () => {
+    expect(
+      isAngularVitestAlreadyWired(
+        `import { storybookAngularVitest } from '${ANGULAR_VITEST_IMPORT_SOURCE}';`
+      )
+    ).toBe(true);
+  });
+
+  it('is true when only the call is present (partial wiring)', () => {
+    expect(
+      isAngularVitestAlreadyWired('plugins: [storybookAngularVitest({}), storybookTest({})]')
+    ).toBe(true);
+  });
+});
+
+describe('collectStorybookTestLocalNames', () => {
+  it('always seeds the bare storybookTest name', () => {
+    const names = collectStorybookTestLocalNames(babelParse('export default {};'));
+    expect(names.has('storybookTest')).toBe(true);
+  });
+
+  it('collects aliased import names', () => {
+    const names = collectStorybookTestLocalNames(
+      babelParse(`import { storybookTest as sbTest } from '@storybook/addon-vitest/vitest-plugin';`)
+    );
+    expect(names.has('sbTest')).toBe(true);
+    expect(names.has('storybookTest')).toBe(true);
+  });
+
+  it('ignores imports from other sources', () => {
+    const names = collectStorybookTestLocalNames(
+      babelParse(`import { storybookTest as other } from 'somewhere-else';`)
+    );
+    expect(names.has('other')).toBe(false);
+  });
+});
+
+describe('injectAngularVitestIntoConfig', () => {
+  it('co-locates the bridge in the same plugins array as storybookTest (case 1)', () => {
+    const out = injectAngularVitestIntoConfig(FRESH_V4);
+    expect(out).not.toBeNull();
+    const callees = pluginCalleesInSameArray(out!);
+    expect(callees).toEqual([ANGULAR_VITEST_PLUGIN_CALL, 'storybookTest']);
+    // Quote style is normalized later by prettier in the real flow; assert on the structural import.
+    expect(out).toContain(`{ ${ANGULAR_VITEST_PLUGIN_CALL} }`);
+    expect(out).toContain(ANGULAR_VITEST_IMPORT_SOURCE);
+  });
+
+  it('adds the scaffold comment (case 20: comments preserved through generate)', () => {
+    const out = injectAngularVitestIntoConfig(FRESH_V4)!;
+    expect(out).toContain('Forwards Angular build options');
+    // The template's own comment must also survive.
+    expect(out).toContain('The plugin will run tests for the stories');
+  });
+
+  it('is alias-aware: co-locates next to an aliased storybookTest (case 2)', () => {
+    const aliased = FRESH_V4.replace(
+      `import { storybookTest } from '@storybook/addon-vitest/vitest-plugin';`,
+      `import { storybookTest as sbTest } from '@storybook/addon-vitest/vitest-plugin';`
+    ).replace('storybookTest({ configDir', 'sbTest({ configDir');
+
+    const out = injectAngularVitestIntoConfig(aliased);
+    expect(out).not.toBeNull();
+    const callees = pluginCalleesInSameArray(out!, 'sbTest');
+    expect(callees).toEqual([ANGULAR_VITEST_PLUGIN_CALL, 'sbTest']);
+  });
+
+  it('returns null on spread storybookTest with no locatable array (case 3)', () => {
+    const spread = `
+      import { storybookTest } from '@storybook/addon-vitest/vitest-plugin';
+      export default { test: { projects: [{ plugins: [...storybookTest()] }] } };
+    `;
+    expect(injectAngularVitestIntoConfig(spread)).toBeNull();
+  });
+
+  it('returns null when storybookTest is not in any array (exotic)', () => {
+    const exotic = `
+      import { storybookTest } from '@storybook/addon-vitest/vitest-plugin';
+      const p = storybookTest();
+      export default { test: { projects: [{ plugins: p }] } };
+    `;
+    expect(injectAngularVitestIntoConfig(exotic)).toBeNull();
+  });
+
+  it('returns null on unparsable content', () => {
+    expect(injectAngularVitestIntoConfig('this is ::: not valid <<< ts')).toBeNull();
+  });
+
+  it('is idempotent: a second pass adds no duplicate import or call (case 8)', () => {
+    const once = injectAngularVitestIntoConfig(FRESH_V4)!;
+    const twice = injectAngularVitestIntoConfig(once);
+    // Already wired by the import source — the string path short-circuits via callers, but the
+    // injector itself must also not duplicate when re-run on already-injected content.
+    expect(twice).not.toBeNull();
+    expect(countOccurrences(twice!, ANGULAR_VITEST_IMPORT_SOURCE)).toBe(1);
+    expect(countOccurrences(twice!, `${ANGULAR_VITEST_PLUGIN_CALL}(`)).toBe(1);
+  });
+
+  it('partial wiring: call already present, adds import without duplicating the call (case 10a)', () => {
+    const callOnly = FRESH_V4.replace(
+      'plugins: [',
+      'plugins: [\n          storybookAngularVitest({}),'
+    );
+    const out = injectAngularVitestIntoConfig(callOnly)!;
+    expect(countOccurrences(out, `${ANGULAR_VITEST_PLUGIN_CALL}(`)).toBe(1);
+    expect(countOccurrences(out, ANGULAR_VITEST_IMPORT_SOURCE)).toBe(1);
+  });
+
+  it('partial wiring: import already present, adds call without duplicating the import (case 10b)', () => {
+    const importOnly = `import { storybookAngularVitest } from '${ANGULAR_VITEST_IMPORT_SOURCE}';\n${FRESH_V4}`;
+    const out = injectAngularVitestIntoConfig(importOnly)!;
+    expect(countOccurrences(out, ANGULAR_VITEST_IMPORT_SOURCE)).toBe(1);
+    expect(countOccurrences(out, `${ANGULAR_VITEST_PLUGIN_CALL}(`)).toBe(1);
+    const callees = pluginCalleesInSameArray(out);
+    expect(callees).toEqual([ANGULAR_VITEST_PLUGIN_CALL, 'storybookTest']);
+  });
+});
+
+describe('injectAngularVitestIntoAst', () => {
+  it('mutates the AST in place and returns true', () => {
+    const ast = babelParse(FRESH_V4);
+    expect(injectAngularVitestIntoAst(ast)).toBe(true);
+    const callees = pluginCalleesInSameArray(generate(ast).code);
+    expect(callees).toEqual([ANGULAR_VITEST_PLUGIN_CALL, 'storybookTest']);
+  });
+
+  it('returns false for non-locatable arrays', () => {
+    const ast = babelParse('export default { test: {} };');
+    expect(injectAngularVitestIntoAst(ast)).toBe(false);
+  });
+
+  it('co-locates in a workspace (defineWorkspace) element plugins array (case 6)', () => {
+    const workspace = `
+      import { defineWorkspace } from 'vitest/config';
+      import { storybookTest } from '@storybook/addon-vitest/vitest-plugin';
+      export default defineWorkspace([
+        './vite.config.ts',
+        {
+          extends: './vite.config.ts',
+          plugins: [storybookTest({ configDir: '.storybook' })],
+          test: { name: 'storybook' },
+        },
+      ]);
+    `;
+    const out = injectAngularVitestIntoConfig(workspace);
+    expect(out).not.toBeNull();
+    const callees = pluginCalleesInSameArray(out!);
+    expect(callees).toEqual([ANGULAR_VITEST_PLUGIN_CALL, 'storybookTest']);
+  });
+
+  it('returns null for a workspace that only references external configs (case 7)', () => {
+    const referenced = `
+      import { defineWorkspace } from 'vitest/config';
+      export default defineWorkspace(['./vite.config.ts', './vitest.storybook.config.ts']);
+    `;
+    expect(injectAngularVitestIntoConfig(referenced)).toBeNull();
+  });
+});