storybookjs · JReinhold · Dec 10, 2024 · Dec 4, 2024 · Dec 4, 2024 · Dec 5, 2024
diff --git a/code/addons/test/src/vitest-plugin/index.ts b/code/addons/test/src/vitest-plugin/index.ts
@@ -5,11 +5,14 @@ import type { ViteUserConfig } from 'vitest/config';
 
 import {
   getInterpretedFile,
-  loadAllPresets,
   normalizeStories,
   validateConfigurationFiles,
 } from 'storybook/internal/common';
-import { StoryIndexGenerator, mapStaticDir } from 'storybook/internal/core-server';
+import {
+  StoryIndexGenerator,
+  experimental_loadStorybook,
+  mapStaticDir,
+} from 'storybook/internal/core-server';
 import { readConfig, vitestTransform } from 'storybook/internal/csf-tools';
 import { MainFileMissingError } from 'storybook/internal/server-errors';
 import type { Presets } from 'storybook/internal/types';
@@ -88,10 +91,8 @@ export const storybookTest = async (options?: UserOptions): Promise<Plugin> => {
     workingDir: WORKING_DIR,
   };
 
-  const presets = await loadAllPresets({
+  const { presets } = await experimental_loadStorybook({
     configDir: finalOptions.configDir,
-    corePresets: [],
-    overridePresets: [],
     packageJson: {},
   });
 
@@ -114,6 +115,16 @@ export const storybookTest = async (options?: UserOptions): Promise<Plugin> => {
   return {
     name: 'vite-plugin-storybook-test',
     enforce: 'pre',
+    async transformIndexHtml(html) {
+      const [headHtmlSnippet, bodyHtmlSnippet] = await Promise.all([
+        presets.apply('previewHead'),
+        presets.apply('previewBody'),
+      ]);
+
+      return html
+        .replace('</head>', `${headHtmlSnippet ?? ''}</head>`)
+        .replace('<body>', `<body>${bodyHtmlSnippet ?? ''}`);
+    },
     async config(inputConfig_DoNotMutate) {
       // ! We're not mutating the input config, instead we're returning a new partial config
       // ! see https://vite.dev/guide/api-plugin.html#config

diff --git a/code/core/src/core-server/index.ts b/code/core/src/core-server/index.ts
@@ -8,3 +8,5 @@ export * from './withTelemetry';
 export { default as build } from './standalone';
 export { mapStaticDir } from './utils/server-statics';
 export { StoryIndexGenerator } from './utils/StoryIndexGenerator';
+
+export { loadStorybook as experimental_loadStorybook } from './load';
diff --git a/code/core/src/core-server/load.ts b/code/core/src/core-server/load.ts
@@ -0,0 +1,83 @@
+import { join, relative, resolve } from 'node:path';
+
+import {
+  getProjectRoot,
+  loadAllPresets,
+  loadMainConfig,
+  resolveAddonName,
+  validateFrameworkName,
+} from '@storybook/core/common';
+import { oneWayHash } from '@storybook/core/telemetry';
+import type { BuilderOptions, CLIOptions, LoadOptions, Options } from '@storybook/core/types';
+import { global } from '@storybook/global';
+
+export async function loadStorybook(
+  options: CLIOptions &
+    LoadOptions &
+    BuilderOptions & {
+      storybookVersion?: string;
+      previewConfigPath?: string;
+    }
+): Promise<Options> {
+  const configDir = resolve(options.configDir);
+
+  const rootDir = getProjectRoot();
+  const cacheKey = oneWayHash(relative(rootDir, configDir));
+
+  options.configType = 'DEVELOPMENT';
+  options.configDir = configDir;
+  options.cacheKey = cacheKey;
+
+  const config = await loadMainConfig(options);
+  const { framework } = config;
+  const corePresets = [];
+
+  let frameworkName = typeof framework === 'string' ? framework : framework?.name;
+  if (!options.ignorePreview) {
+    validateFrameworkName(frameworkName);
+  }
+  if (frameworkName) {
+    corePresets.push(join(frameworkName, 'preset'));
+  }
+
+  frameworkName = frameworkName || 'custom';
+
+  // Load first pass: We need to determine the builder
+  // We need to do this because builders might introduce 'overridePresets' which we need to take into account
+  // We hope to remove this in SB8
+
+  let presets = await loadAllPresets({
+    corePresets,
+    overridePresets: [
+      require.resolve('@storybook/core/core-server/presets/common-override-preset'),
+    ],
+    ...options,
+    isCritical: true,
+  });
+
+  const { renderer } = await presets.apply('core', {});
+  const resolvedRenderer = renderer && resolveAddonName(options.configDir, renderer, options);
+
+  // Load second pass: all presets are applied in order
+
+  presets = await loadAllPresets({
+    corePresets: [
+      require.resolve('@storybook/core/core-server/presets/common-preset'),
+      ...(resolvedRenderer ? [resolvedRenderer] : []),
+      ...corePresets,
+    ],
+    overridePresets: [
+      require.resolve('@storybook/core/core-server/presets/common-override-preset'),
+    ],
+    ...options,
+  });
+
+  const features = await presets.apply('features');
+  global.FEATURES = features;
+
+  return {
+    ...options,
+    presets,
+    features,
+  } as Options;
+}
diff --git a/test-storybooks/portable-stories-kitchen-sink/react/.storybook/main.ts b/test-storybooks/portable-stories-kitchen-sink/react/.storybook/main.ts
@@ -14,5 +14,11 @@ const config: StorybookConfig = {
   core: {
     disableWhatsNewNotifications: true
   },
+  previewHead: (head = '') => `${head}
+  <style>
+    body {
+      border: 1px solid red;
+    }
+  </style>`,
 };
 export default config;
diff --git a/test-storybooks/portable-stories-kitchen-sink/react/.storybook/preview-head.html b/test-storybooks/portable-stories-kitchen-sink/react/.storybook/preview-head.html
@@ -0,0 +1,5 @@
+<style>
+  body {
+    background-color: rgb(250, 250, 210);
+  }
+</style>
diff --git a/test-storybooks/portable-stories-kitchen-sink/react/e2e-tests/component-testing.spec.ts b/test-storybooks/portable-stories-kitchen-sink/react/e2e-tests/component-testing.spec.ts
@@ -28,6 +28,9 @@ const setForceFailureFlag = async (value: boolean) => {
 
   // Write the updated content back to the file asynchronously
   await fs.writeFile(testStoryPath, updatedContent);
+
+  // the file change causes a HMR event, which causes a browser reload,and that can take a few seconds
+  await new Promise((resolve) => setTimeout(resolve, 2000));
 };
 
 test.describe("component testing", () => {