Merge pull request storybookjs#403 from storybookjs/refactor/extract-setup-page-scripts

Refactor: Extract the setup page scripts into a separate file

Author: yannbf

src/setup-page-script.ts

@@ -0,0 +1,330 @@
+/**
+ * PLEASE READ THIS BEFORE EDITING THIS FILE:
+ *
+ * This file is a template to the content which is injected to the Playwright page via the ./setup-page.ts file.
+ * setup-page.ts will read the contents of this file and replace values that use {{x}} pattern, and they should be put right below:
+ */
+
+// All of these variables will be replaced once this file is processed.
+const referenceURL: string | undefined = '{{referenceURL}}';
+const targetURL: string = '{{targetURL}}';
+const testRunnerVersion: string = '{{testRunnerVersion}}';
+const failOnConsole: string = '{{failOnConsole}}';
+const renderedEvent: string = '{{renderedEvent}}';
+const viewMode: string = '{{viewMode}}';
+const debugPrintLimit = parseInt('{{debugPrintLimit}}', 10);
+
+// Type definitions for function parameters and return types
+type Colorizer = (message: string) => string;
+
+const bold: Colorizer = (message: string) => `\u001b[1m${message}\u001b[22m`;
+const magenta: Colorizer = (message: string) => `\u001b[35m${message}\u001b[39m`;
+const blue: Colorizer = (message: string) => `\u001b[34m${message}\u001b[39m`;
+const red: Colorizer = (message: string) => `\u001b[31m${message}\u001b[39m`;
+const yellow: Colorizer = (message: string) => `\u001b[33m${message}\u001b[39m`;
+
+// Constants
+var LIMIT_REPLACE_NODE = '[...]';
+var CIRCULAR_REPLACE_NODE = '[Circular]';
+
+// Arrays for tracking replacements
+var arr: any[] = [];
+var replacerStack: any[] = [];
+
+// Default options for stringification
+function defaultOptions(): { depthLimit: number; edgesLimit: number } {
+  return {
+    depthLimit: Number.MAX_SAFE_INTEGER,
+    edgesLimit: Number.MAX_SAFE_INTEGER,
+  };
+}
+
+// Stringify function
+function stringify(
+  obj: any,
+  replacer: ((key: string, value: any) => any) | null,
+  spacer: string | number | null,
+  options?: { depthLimit: number; edgesLimit: number }
+): string {
+  if (typeof options === 'undefined') {
+    options = defaultOptions();
+  }
+
+  decirc(obj, '', 0, [], undefined, 0, options);
+  var res: string;
+  try {
+    if (replacerStack.length === 0) {
+      // @ts-expect-error TODO: check why TS complains about this
+      res = JSON.stringify(obj, replacer, spacer);
+    } else {
+      // @ts-expect-error TODO: check why TS complains about this
+      res = JSON.stringify(obj, replaceGetterValues(replacer), spacer);
+    }
+  } catch (_) {
+    return JSON.stringify('[unable to serialize, circular reference is too complex to analyze]');
+  } finally {
+    while (arr.length !== 0) {
+      var part = arr.pop();
+      if (part && part.length === 4) {
+        Object.defineProperty(part[0], part[1], part[3]);
+      } else if (part) {
+        part[0][part[1]] = part[2];
+      }
+    }
+  }
+  return res;
+}
+
+// Handle circular references and limits
+function decirc(
+  val: any,
+  k: string,
+  edgeIndex: number,
+  stack: any[],
+  parent: any | undefined,
+  depth: number,
+  options: { depthLimit: number; edgesLimit: number }
+): void {
+  depth += 1;
+  var i: number;
+  if (typeof val === 'object' && val !== null) {
+    for (i = 0; i < stack.length; i++) {
+      if (stack[i] === val) {
+        setReplace(CIRCULAR_REPLACE_NODE, val, k, parent);
+        return;
+      }
+    }
+
+    if (depth > options.depthLimit || edgeIndex + 1 > options.edgesLimit) {
+      setReplace(LIMIT_REPLACE_NODE, val, k, parent);
+      return;
+    }
+
+    stack.push(val);
+    if (Array.isArray(val)) {
+      for (i = 0; i < val.length; i++) {
+        decirc(val[i], i.toString(), i, stack, val, depth, options);
+      }
+    } else {
+      var keys = Object.keys(val);
+      for (i = 0; i < keys.length; i++) {
+        var key = keys[i];
+        decirc(val[key], key, i, stack, val, depth, options);
+      }
+    }
+    stack.pop();
+  }
+}
+
+// Set replacement values in objects
+function setReplace(replace: any, val: any, k: string, parent: any | undefined): void {
+  if (!parent) return;
+  var propertyDescriptor = Object.getOwnPropertyDescriptor(parent, k);
+  if (propertyDescriptor && propertyDescriptor.get !== undefined) {
+    if (propertyDescriptor.configurable) {
+      Object.defineProperty(parent, k, { value: replace });
+      arr.push([parent, k, val, propertyDescriptor]);
+    } else {
+      replacerStack.push([val, k, replace]);
+    }
+  } else {
+    parent[k] = replace;
+    arr.push([parent, k, val]);
+  }
+}
+
+// Replace getter values
+function replaceGetterValues(
+  replacer?: (this: any, key: string, value: any) => any
+): (this: any, key: string, value: any) => any {
+  const effectiveReplacer = replacer ?? ((_k: string, v: any) => v);
+  return function (this: any, key: string, val: any): any {
+    if (replacerStack.length > 0) {
+      for (var i = 0; i < replacerStack.length; i++) {
+        var part = replacerStack[i];
+        if (part[1] === key && part[0] === val) {
+          val = part[2];
+          replacerStack.splice(i, 1);
+          break;
+        }
+      }
+    }
+    return effectiveReplacer.call(this, key, val);
+  };
+}
+
+// Compose message function
+function composeMessage(args: any): string {
+  if (args instanceof Error) {
+    return `${args.name}: ${args.message}\n${args.stack}`;
+  }
+  if (typeof args === 'undefined') return 'undefined';
+  if (typeof args === 'string') return args;
+  return stringify(args, null, null, { depthLimit: 5, edgesLimit: 100 });
+}
+
+// Truncate long strings
+function truncate(input: string, limit: number): string {
+  if (input.length > limit) {
+    return input.substring(0, limit) + '…';
+  }
+  return input;
+}
+
+// Add extra information to the user agent
+function addToUserAgent(extra: string): void {
+  const originalUserAgent = globalThis.navigator.userAgent;
+  if (!originalUserAgent.includes(extra)) {
+    Object.defineProperty(globalThis.navigator, 'userAgent', {
+      get: function () {
+        return [originalUserAgent, extra].join(' ');
+      },
+      configurable: true,
+    });
+  }
+}
+
+// Custom error class
+class StorybookTestRunnerError extends Error {
+  constructor(storyId: string, errorMessage: string, logs: string[] = []) {
+    super(errorMessage);
+    this.name = 'StorybookTestRunnerError';
+    const storyUrl = `${referenceURL ?? targetURL}?path=/story/${storyId}`;
+    const finalStoryUrl = `${storyUrl}&addonPanel=storybook/interactions/panel`;
+    const separator = '\n\n--------------------------------------------------';
+    const extraLogs =
+      logs.length > 0 ? separator + '\n\nBrowser logs:\n\n' + logs.join('\n\n') : '';
+
+    this.message = `\nAn error occurred in the following story. Access the link for full output:\n${finalStoryUrl}\n\nMessage:\n ${truncate(
+      errorMessage,
+      debugPrintLimit
+    )}\n${extraLogs}`;
+  }
+}
+
+// @ts-expect-error Global function to throw custom error, used by the test runner or user
+async function __throwError(storyId: string, errorMessage: string, logs: string[]): Promise<void> {
+  throw new StorybookTestRunnerError(storyId, errorMessage, logs);
+}
+
+// Wait for Storybook to load
+async function __waitForStorybook(): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      reject();
+    }, 10000);
+
+    if (document.querySelector('#root') || document.querySelector('#storybook-root')) {
+      clearTimeout(timeout);
+      return resolve();
+    }
+
+    const observer = new MutationObserver(() => {
+      if (document.querySelector('#root') || document.querySelector('#storybook-root')) {
+        clearTimeout(timeout);
+        resolve();
+        observer.disconnect();
+      }
+    });
+
+    observer.observe(document.body, {
+      childList: true,
+      subtree: true,
+    });
+  });
+}
+
+// Get context from Storybook
+// @ts-expect-error Global function to get context, used by the test runner or user
+async function __getContext(storyId: string): Promise<any> {
+  // @ts-expect-error globally defined via Storybook
+  return globalThis.__STORYBOOK_PREVIEW__.storyStore.loadStory({ storyId });
+}
+
+// @ts-expect-error Global main test function, used by the test runner
+async function __test(storyId: string): Promise<any> {
+  try {
+    await __waitForStorybook();
+  } catch (err) {
+    const message = `Timed out waiting for Storybook to load after 10 seconds. Are you sure the Storybook is running correctly in that URL? Is the Storybook private (e.g. under authentication layers)?\n\n\nHTML: ${document.body.innerHTML}`;
+    throw new StorybookTestRunnerError(storyId, message);
+  }
+
+  // @ts-expect-error globally defined via Storybook
+  const channel = globalThis.__STORYBOOK_ADDONS_CHANNEL__;
+  if (!channel) {
+    throw new StorybookTestRunnerError(
+      storyId,
+      'The test runner could not access the Storybook channel. Are you sure the Storybook is running correctly in that URL?'
+    );
+  }
+
+  addToUserAgent(`(StorybookTestRunner@${testRunnerVersion})`);
+
+  // Collect logs to show upon test error
+  let logs: string[] = [];
+  let hasErrors = false;
+
+  type ConsoleMethod = 'log' | 'group' | 'warn' | 'error' | 'trace' | 'groupCollapsed';
+
+  const spyOnConsole = (method: ConsoleMethod, name: string): void => {
+    const originalFn = console[method].bind(console);
+    console[method] = function () {
+      if (failOnConsole === 'true' && method === 'error') {
+        hasErrors = true;
+      }
+      const message = Array.from(arguments).map(composeMessage).join(', ');
+      const prefix = `${bold(name)}: `;
+      logs.push(prefix + message);
+      originalFn(...arguments);
+    };
+  };
+
+  // Console methods + color function for their prefix
+  const spiedMethods: { [key: string]: Colorizer } = {
+    log: blue,
+    warn: yellow,
+    error: red,
+    trace: magenta,
+    group: magenta,
+    groupCollapsed: magenta,
+  };
+
+  Object.entries(spiedMethods).forEach(([method, color]) => {
+    spyOnConsole(method as ConsoleMethod, color(method));
+  });
+
+  return new Promise((resolve, reject) => {
+    channel.on(renderedEvent, () => {
+      if (hasErrors) {
+        return reject(new StorybookTestRunnerError(storyId, 'Browser console errors', logs));
+      }
+      return resolve(document.getElementById('root'));
+    });
+    channel.on('storyUnchanged', () => resolve(document.getElementById('root')));
+    channel.on('storyErrored', ({ description }: { description: string }) =>
+      reject(new StorybookTestRunnerError(storyId, description, logs))
+    );
+    channel.on('storyThrewException', (error: Error) =>
+      reject(new StorybookTestRunnerError(storyId, error.message, logs))
+    );
+    channel.on('playFunctionThrewException', (error: Error) =>
+      reject(new StorybookTestRunnerError(storyId, error.message, logs))
+    );
+    channel.on('storyMissing', (id: string) => {
+      if (id === storyId) {
+        reject(
+          new StorybookTestRunnerError(
+            storyId,
+            'The story was missing when trying to access it.',
+            logs
+          )
+        );
+      }
+    });
+
+    channel.emit('setCurrentStory', { storyId, viewMode });
+  });
+}
+
+export {};