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I will install Snapshot Testing with Storybook under Angular 12. I install jest $ yarn add --dev jest jest-preset-angular @types/jest and make Settings

"jest": {
  "preset": "jest-preset-angular",
  "setupFilesAfterEnv": ["<rootDir>/src/setupJest.ts"]
}

and set setupJest.ts Data with only one line import 'jest-preset-angular/setup-jest';.

Thats the Jest Setup. This Works for me.

The problem is the Storyshorts Addon from Storybook. I install Storyshorts yarn add @storybook/addon-storyshots --dev and create file src/storyshorts.test.js with this code:

import initStoryshots from '@storybook/addon-storyshots';

initStoryshots();

When I run the command jest in my Angular Project I become this error:

Cannot find module 'jest-preset-angular/build/setup-jest' from 'node_modules/@storybook/addon-storyshots/dist/ts3.9/frameworks/angular/loader.js'
  at Resolver.resolveModule (node_modules/jest-resolve/build/resolver.js:324:11)
  at setupAngularJestPreset (node_modules/@storybook/addon-storyshots/dist/ts3.9/frameworks/angular/loader.js:36:14)
  at Object.load (node_modules/@storybook/addon-storyshots/dist/ts3.9/frameworks/angular/loader.js:43:5)
  at Object.loadFramework [as default] (node_modules/@storybook/addon-storyshots/dist/ts3.9/frameworks/frameworkLoader.js:26:19)
  at Object.testStorySnapshots [as default] (node_modules/@storybook/addon-storyshots/dist/ts3.9/api/index.js:42:39)

My Package.json has this entries:

...
"@storybook/addon-storyshots": "^6.3.12",
"@types/jest": "^27.0.2",
"jest": "^27.3.1",
"jest-preset-angular": "^10.0.1",

and Angular 12 packages.

1 Answers1

4

EDIT : >= Angular 16

Context

  • With jest-preset-angular 13.1.X
  • With @storybook/addon-storyshots 7.X.X

You'll not be able to run Storyshots anymore due to a bug (TypeError: Cannot destructure property 'imports' of 'analyzedMetadata' as it is undefined.) A PR is currently open to fix it (https://github.com/storybookjs/storybook/pull/23555).

I’ll provide the new jest configuration when the PR will be merged.

Also, you should note that StoryShots will be deprecated in a near futur and will be replaced by the test-runner (a migration guide will be provided by the core team, stay tune).

Therefore, Storyshots will not be improved / changed (except by the community until its deprecation date).

EDIT: >= Angular 13 :

Context

  • With jest-preset-angular 12.X.X
  • With @storybook/addon-storyshots 6.5.X

As I kept Karma/Jasmine for unit testing (bigger community), Jest is only for snapshots tests with Storybook, so my jest.config.js is under the .storybook folder and I created a specific tsconfig file.

jest.config.js

const { defaults: jestNgPreset } = require('jest-preset-angular/presets');

/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
module.exports = {
  rootDir: '../',
  preset: 'jest-preset-angular',
  setupFilesAfterEnv: ['<rootDir>/.storybook/setup-jest.ts'],
  // Ensure to run ngcc for uncompliant Ivy lib
  globalSetup: 'jest-preset-angular/global-setup',
  globals: {
    'ts-jest': {
       ...jestNgPreset.globals['ts-jest'],
      tsconfig: '<rootDir>/.storybook/tsconfig.storyshots.json',
    },
  },
  transform: {
    ...jestNgPreset.transform,
    '^.+\\.stories\\.mdx?$': '<rootDir>/.storybook/empty.js',
  },
  // Don't transform files in node_modules, except those which match those patterns
  transformIgnorePatterns: [
    '<rootDir>/node_modules/(?!.*\\.mjs$|@storybook/addon-docs/angular|@angular|primeng|angular-auth-oidc-client)',
  ],
  moduleNameMapper: {
'jest-preset-angular/build/setup-jest': 'jest-preset-angular/setup-jest',
'jest-preset-angular/build/AngularNoNgAttributesSnapshotSerializer':
  'jest-preset-angular/build/serializers/no-ng-attributes',
'jest-preset-angular/build/AngularSnapshotSerializer':
  'jest-preset-angular/build/serializers/ng-snapshot',
'jest-preset-angular/build/HTMLCommentSerializer':
  'jest-preset-angular/build/serializers/html-comment',
  },
};

tsconfig.storyshots.json

{
  "extends": "../tsconfig.json",
  "compilerOptions": {
    "skipLibCheck": true,
    "outDir": "./out-tsc/spec",
    "module": "CommonJS",
    "types": ["jest"]
  },
  "files": ["./typings.d.ts"]
}

empty.js

/**
 * This file is used to prevent mdx files importation during snapshot testing with Jest (see jest.config.js).
 * I tried with testPathIgnorePatterns or storyKindRegex, but impossible.
 */
module.exports = {
  process: function () {
    return { code: '' };
  },
};

=== Original (Angular 12) ===

Welcome in hell :D !

For your problem : storyshots addon try to load setup-jest.ts file from a bad path. Since jest-preset-angular version 9, setup-jest.ts is no longer located into jest-preset-angular/build/ folder (and this is not the only impacted file). Storyshots addon doesn't handle this change yet, so you can use moduleNameMapper from jest config to rewrite path and fix your issue.

See my jest.config.js as example :

require('jest-preset-angular/ngcc-jest-processor');

module.exports = {
  preset: 'jest-preset-angular',
  setupFilesAfterEnv: ['<rootDir>/setup-jest.ts'],
  transformIgnorePatterns: [
    '<rootDir>/node_modules/(?!(@storybook/addon-docs))',
  ],
  moduleNameMapper: {
    'jest-preset-angular/build/setup-jest': 'jest-preset-angular/setup-jest',
    'jest-preset-angular/build/AngularNoNgAttributesSnapshotSerializer':
      'jest-preset-angular/build/serializers/no-ng-attributes',
    'jest-preset-angular/build/AngularSnapshotSerializer':
      'jest-preset-angular/build/serializers/ng-snapshot',
    'jest-preset-angular/build/HTMLCommentSerializer':
      'jest-preset-angular/build/serializers/html-comment',
  },
};

If you need more explanation, ask me :)

Adrien SAULNIER
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  • What is in your tsconfig.storyshots.json ? – Haskell Jun 08 '22 at 18:26
  • I'll show you my config, I'll edit my answer in few minutes – Adrien SAULNIER Jun 24 '22 at 08:08
  • I tried to follow your solution but it results in the following error message: ```Module /.storybook/empty.js in the transform option was not found.``` (and the file really doesn't exist). I wonder if there is any fully working example for Angular 15 with Storybook with the storyshots addon but still using Karma for Unit Testing. I was only able to find pieces here and there but all seemed to be configured differently and I can't work out how to put them as I lack the experience with Storybook.` Executed with ```jest storybook.test.ts --config=.storybook/jest.config.js``` – patrickuhlmlann Feb 07 '23 at 14:54
  • Hey ! Sorry for the delayed answer.... empty.js file is a custom file that I created, maybe you don't need it. I created it to prevent mdx files importation during snapshot testing with Jest – Adrien SAULNIER Jul 21 '23 at 13:59
  • @patrickuhlmlann I'm trying to edit my response to update jest config for Ng16 but StoryShots are broken (with Ng16 and Storybook v7.1). Are you in v16 ? – Adrien SAULNIER Jul 21 '23 at 14:12
  • @AdrienSAULNIER: No sorry. We are not using StoryShots anymore. – patrickuhlmlann Jul 22 '23 at 13:54