refactor: move challenge build outside client (#65513)

client/package.json

@@ -47,14 +47,13 @@
     "@babel/preset-env": "7.23.7",
     "@babel/preset-react": "7.23.3",
     "@babel/preset-typescript": "7.23.3",
-    "@babel/standalone": "7.23.7",
     "@codesandbox/sandpack-react": "2.6.9",
     "@codesandbox/sandpack-themes": "2.0.21",
     "@fortawesome/fontawesome-svg-core": "6.7.1",
     "@fortawesome/free-brands-svg-icons": "6.7.1",
     "@fortawesome/free-solid-svg-icons": "6.7.1",
     "@fortawesome/react-fontawesome": "0.2.2",
-    "@freecodecamp/loop-protect": "3.0.0",
+    "@freecodecamp/challenge-builder": "workspace:*",
     "@freecodecamp/ui": "5.0.1",
     "@gatsbyjs/reach-router": "1.3.9",
     "@growthbook/growthbook-react": "1.6.0",
@@ -141,10 +140,10 @@
   },
   "devDependencies": {
     "@babel/plugin-syntax-dynamic-import": "7.8.3",
+    "@freecodecamp/browser-scripts": "workspace:*",
+    "@freecodecamp/curriculum": "workspace:*",
     "@freecodecamp/eslint-config": "workspace:*",
     "@freecodecamp/shared": "workspace:*",
-    "@freecodecamp/curriculum": "workspace:*",
-    "@freecodecamp/browser-scripts": "workspace:*",
     "@testing-library/jest-dom": "^6.8.0",
     "@testing-library/react": "12.1.5",
     "@testing-library/react-hooks": "^8.0.1",

client/src/templates/Challenges/components/completion-modal.test.tsx

@@ -1,6 +1,8 @@
 import React from 'react';
 import { runSaga } from 'redux-saga';
 import { describe, test, it, expect, beforeEach, vi, Mock } from 'vitest';
+import { buildChallenge } from '@freecodecamp/challenge-builder/build';
+
 import { render } from '../../../../utils/test-utils';
 
 import { getCompletedPercentage } from '../../../utils/get-completion-percentage';
@@ -14,7 +16,7 @@ import {
   isBuildEnabledSelector,
   isBlockNewlyCompletedSelector
 } from '../redux/selectors';
-import { buildChallenge, getTestRunner } from '../utils/build';
+import { getTestRunner } from '../utils/build';
 import CompletionModal, { combineFileData } from './completion-modal';
 vi.mock('../../../analytics');
 vi.mock('../../../utils/fire-confetti');
@@ -22,6 +24,7 @@ vi.mock('../../../components/Progress');
 vi.mock('../redux/selectors');
 vi.mock('../utils/build');
 vi.mock('../../../utils/get-words');
+vi.mock('@freecodecamp/challenge-builder/build');
 const mockFireConfetti = fireConfetti as Mock;
 const mockTestRunner = vi.fn().mockReturnValue({ pass: true });
 const mockBuildEnabledSelector = isBuildEnabledSelector as Mock;

client/src/templates/Challenges/redux/execute-challenge-saga.js

@@ -15,6 +15,8 @@ import {
 } from 'redux-saga/effects';
 
 import { challengeTypes } from '@freecodecamp/shared/config/challenge-types';
+import { buildChallenge } from '@freecodecamp/challenge-builder/build';
+
 import { createFlashMessage } from '../../../components/Flash/redux';
 import { FlashMessages } from '../../../components/Flash/redux/flash-messages';
 import {
@@ -25,7 +27,6 @@ import {
 } from '../../../utils/challenge-request-helpers';
 import { playTone } from '../../../utils/tone';
 import {
-  buildChallenge,
   canBuildChallenge,
   challengeHasPreview,
   getTestRunner,

client/src/templates/Challenges/utils/build.ts

@@ -1,13 +1,15 @@
 import { challengeTypes } from '@freecodecamp/shared/config/challenge-types';
+import type { ChallengeFile } from '@freecodecamp/shared/utils/polyvinyl';
 
-import type { ChallengeFile } from '../../../redux/prop-types';
-import { concatHtml } from '../rechallenge/builders';
 import {
   getTransformers,
   embedFilesInHtml,
   getPythonTransformers,
   getMultifileJSXTransformers
-} from '../rechallenge/transformers';
+} from '@freecodecamp/challenge-builder/transformers';
+import { concatHtml } from '@freecodecamp/challenge-builder/builders';
+import { runnerTypes } from '@freecodecamp/challenge-builder/build';
+
 import {
   runTestsInTestFrame,
   createMainPreviewFramer,
@@ -97,56 +99,6 @@ export function canBuildChallenge(challengeData: BuildChallengeData): boolean {
   return Object.prototype.hasOwnProperty.call(buildFunctions, challengeType);
 }
 
-export async function buildChallenge(
-  challengeData: BuildChallengeData,
-  options: BuildOptions
-) {
-  const { challengeType } = challengeData;
-  const build = buildFunctions[challengeType];
-  if (build) {
-    return build(challengeData, options);
-  }
-  throw new Error(`Cannot build challenge of type ${challengeType}`);
-}
-
-export const runnerTypes: Record<
-  (typeof challengeTypes)[keyof typeof challengeTypes],
-  'javascript' | 'dom' | 'python'
-> = {
-  [challengeTypes.html]: 'dom',
-  [challengeTypes.js]: 'javascript',
-  [challengeTypes.backend]: 'dom',
-  [challengeTypes.zipline]: 'dom',
-  [challengeTypes.frontEndProject]: 'dom',
-  [challengeTypes.backEndProject]: 'dom',
-  [challengeTypes.pythonProject]: 'python',
-  [challengeTypes.jsProject]: 'javascript',
-  [challengeTypes.modern]: 'dom',
-  [challengeTypes.step]: 'dom',
-  [challengeTypes.quiz]: 'dom',
-  [challengeTypes.invalid]: 'dom',
-  [challengeTypes.video]: 'dom',
-  [challengeTypes.codeAllyPractice]: 'dom',
-  [challengeTypes.codeAllyCert]: 'dom',
-  [challengeTypes.multifileCertProject]: 'dom',
-  [challengeTypes.theOdinProject]: 'dom',
-  [challengeTypes.colab]: 'dom',
-  [challengeTypes.exam]: 'dom',
-  [challengeTypes.msTrophy]: 'dom',
-  [challengeTypes.multipleChoice]: 'dom',
-  [challengeTypes.python]: 'python',
-  [challengeTypes.dialogue]: 'dom',
-  [challengeTypes.fillInTheBlank]: 'dom',
-  [challengeTypes.multifilePythonCertProject]: 'python',
-  [challengeTypes.generic]: 'dom',
-  [challengeTypes.lab]: 'dom',
-  [challengeTypes.jsLab]: 'javascript',
-  [challengeTypes.pyLab]: 'python',
-  [challengeTypes.dailyChallengeJs]: 'javascript',
-  [challengeTypes.dailyChallengePy]: 'python',
-  [challengeTypes.review]: 'dom'
-};
-
 export async function getTestRunner(buildData: BuildChallengeData) {
   const { challengeType } = buildData;
   // TODO: Fully type BuildChallengeData

curriculum/package.json

@@ -48,9 +48,10 @@
   "devDependencies": {
     "@babel/core": "7.23.7",
     "@babel/register": "7.23.7",
+    "@freecodecamp/browser-scripts": "workspace:*",
+    "@freecodecamp/challenge-builder": "workspace:*",
     "@freecodecamp/eslint-config": "workspace:*",
     "@freecodecamp/shared": "workspace:*",
-    "@freecodecamp/browser-scripts": "workspace:*",
     "@total-typescript/ts-reset": "^0.6.1",
     "@types/debug": "^4.1.12",
     "@types/js-yaml": "4.0.5",

curriculum/src/test/test-challenges.js

@@ -26,16 +26,16 @@ import { sortChallenges } from './utils/sort-challenges.js';
 const { flatten, isEmpty, cloneDeep } = lodash;
 
 vi.mock(
-  '../../../client/src/templates/Challenges/utils/typescript-worker-handler',
+  '@freecodecamp/challenge-builder/typescript-worker-handler',
   async importOriginal => {
     const actual = await importOriginal();
 
     // ts and tsvfs must match the versions used in the typescript-worker.
     const tsvfs = await import('@typescript/vfs-1.6.1');
     const ts = await import('typescript-5.9.2');
-    // use the same TS compiler as the client
+    // use the same TS compiler as the challenge-builder
     const tsCompiler = await import(
-      '../../../tools/client-plugins/browser-scripts/modules/typescript-compiler'
+      '@freecodecamp/browser-scripts/ts-compiler'
     );
     const compiler = new tsCompiler.Compiler(ts, tsvfs);
     await compiler.setup({ useNodeModules: true });
@@ -151,7 +151,7 @@ async function populateTestsForLang({ lang, challenges, meta }) {
   // Presumably this is because we import from_this file in the generated block
   // test files and that happens before the mock is applied.
   const { buildChallenge } = await import(
-    '../../../client/src/templates/Challenges/utils/build'
+    '@freecodecamp/challenge-builder/build'
   );
   const validateChallenge = challengeSchemaValidator();
 
@@ -370,9 +370,7 @@ async function createTestRunner(
   buildChallenge,
   solutionFromNext
 ) {
-  const { runnerTypes } = await import(
-    '../../../client/src/templates/Challenges/utils/build'
-  );
+  const { runnerTypes } = await import('@freecodecamp/challenge-builder/build');
 
   const challengeFiles = replaceChallengeFilesContentsWithSolutions(
     challenge.challengeFiles,

packages/challenge-builder/.gitignore

@@ -0,0 +1 @@
+dist

packages/challenge-builder/.lintstagedrc.mjs

@@ -0,0 +1,4 @@
+/* eslint-disable filenames-simple/naming-convention */
+import { createLintStagedConfig } from '@freecodecamp/eslint-config/lintstaged';
+
+export default createLintStagedConfig(import.meta.dirname);

packages/challenge-builder/eslint.config.js

@@ -0,0 +1,18 @@
+import { configTypeChecked } from '@freecodecamp/eslint-config/base';
+import globals from 'globals';
+
+import { defineConfig } from 'eslint/config';
+
+const baseLanguageOptions = {
+  globals: {
+    ...globals.browser,
+    ...globals.node // TODO: necessary?
+  }
+};
+
+export default defineConfig({
+  extends: [configTypeChecked],
+  languageOptions: {
+    ...baseLanguageOptions
+  }
+});

packages/challenge-builder/package.json

@@ -0,0 +1,51 @@
+{
+  "name": "@freecodecamp/challenge-builder",
+  "version": "0.0.1",
+  "author": "freeCodeCamp <team@freecodecamp.org>",
+  "license": "BSD-3-Clause",
+  "description": "Builds challenges for testing and rendering",
+  "private": false,
+  "engines": {
+    "node": ">=24",
+    "pnpm": ">=10"
+  },
+  "exports": {
+    "./build": "./dist/build.js",
+    "./transformers": "./dist/transformers.js",
+    "./typescript-worker-handler": "./dist/typescript-worker-handler.js",
+    "./builders": "./dist/builders.js"
+  },
+  "scripts": {
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:ui": "vitest --ui",
+    "type-check": "tsc --noEmit",
+    "compile": "tsc",
+    "lint": "eslint --max-warnings 0"
+  },
+  "type": "module",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/freeCodeCamp/freeCodeCamp.git"
+  },
+  "bugs": {
+    "url": "https://github.com/freeCodeCamp/freeCodeCamp/issues"
+  },
+  "homepage": "https://github.com/freeCodeCamp/freeCodeCamp#readme",
+  "devDependencies": {
+    "@freecodecamp/eslint-config": "workspace:*",
+    "@types/lodash-es": "4.17.12",
+    "@vitest/ui": "^3.2.4",
+    "eslint": "^9.39.1",
+    "vitest": "^3.2.4"
+  },
+  "dependencies": {
+    "@babel/preset-env": "7.23.7",
+    "@babel/preset-react": "7.28.5",
+    "@babel/standalone": "7.23.7",
+    "@freecodecamp/browser-scripts": "workspace:*",
+    "@freecodecamp/loop-protect": "3.0.0",
+    "@freecodecamp/shared": "workspace:*",
+    "lodash-es": "4.17.23"
+  }
+}

packages/challenge-builder/src/build.ts

@@ -0,0 +1,269 @@
+import { challengeTypes } from '@freecodecamp/shared/config/challenge-types';
+import type { ChallengeFile } from '@freecodecamp/shared/utils/polyvinyl';
+
+import { concatHtml } from './builders.js';
+import {
+  getTransformers,
+  embedFilesInHtml,
+  getPythonTransformers,
+  getMultifileJSXTransformers
+} from './transformers.js';
+
+interface Source {
+  index: string;
+  contents?: string;
+  editableContents: string;
+}
+
+interface BuildChallengeData {
+  challengeType: number;
+  challengeFiles?: ChallengeFile[];
+  required: { src?: string }[];
+  template: string;
+  url: string;
+}
+
+interface BuildOptions {
+  preview: boolean;
+  disableLoopProtectTests: boolean;
+  disableLoopProtectPreview: boolean;
+  usesTestRunner?: boolean;
+}
+
+type ApplyFunctionProps = (
+  file: ChallengeFile
+) => Promise<ChallengeFile> | ChallengeFile;
+
+const applyFunction =
+  (fn: ApplyFunctionProps) => async (file: ChallengeFile) => {
+    try {
+      if (file.error) {
+        return file;
+      }
+      const newFile = await fn.call(this, file);
+      if (typeof newFile !== 'undefined') {
+        return newFile;
+      }
+      return file;
+    } catch (error) {
+      return { ...file, error };
+    }
+  };
+
+const composeFunctions = (...fns: ApplyFunctionProps[]) =>
+  fns.map(applyFunction).reduce((f, g) => x => f(x).then(g));
+
+function buildSourceMap(challengeFiles: ChallengeFile[]): Source | undefined {
+  // TODO: rename sources.index to sources.contents.
+  const source: Source | undefined = challengeFiles?.reduce(
+    (sources, challengeFile) => {
+      sources.index += challengeFile.source || '';
+      sources.contents = sources.index;
+      sources.editableContents += challengeFile.editableContents || '';
+      return sources;
+    },
+    {
+      index: '',
+      editableContents: ''
+    } as Source
+  );
+  return source;
+}
+
+export const buildFunctions = {
+  [challengeTypes.js]: buildJSChallenge,
+  [challengeTypes.jsProject]: buildJSChallenge,
+  [challengeTypes.html]: buildDOMChallenge,
+  [challengeTypes.modern]: buildDOMChallenge,
+  [challengeTypes.backend]: buildBackendChallenge,
+  [challengeTypes.backEndProject]: buildBackendChallenge,
+  [challengeTypes.pythonProject]: buildBackendChallenge,
+  [challengeTypes.multifileCertProject]: buildDOMChallenge,
+  [challengeTypes.colab]: buildBackendChallenge,
+  [challengeTypes.python]: buildPythonChallenge,
+  [challengeTypes.multifilePythonCertProject]: buildPythonChallenge,
+  [challengeTypes.lab]: buildDOMChallenge,
+  [challengeTypes.jsLab]: buildJSChallenge,
+  [challengeTypes.pyLab]: buildPythonChallenge,
+  [challengeTypes.dailyChallengeJs]: buildJSChallenge,
+  [challengeTypes.dailyChallengePy]: buildPythonChallenge
+};
+
+export function canBuildChallenge(challengeData: BuildChallengeData): boolean {
+  const { challengeType } = challengeData;
+  return Object.prototype.hasOwnProperty.call(buildFunctions, challengeType);
+}
+
+export async function buildChallenge(
+  challengeData: BuildChallengeData,
+  options: BuildOptions
+) {
+  const { challengeType } = challengeData;
+  const build = buildFunctions[challengeType];
+  if (build) {
+    return build(challengeData, options);
+  }
+  throw new Error(`Cannot build challenge of type ${challengeType}`);
+}
+
+export const runnerTypes: Record<
+  (typeof challengeTypes)[keyof typeof challengeTypes],
+  'javascript' | 'dom' | 'python'
+> = {
+  [challengeTypes.html]: 'dom',
+  [challengeTypes.js]: 'javascript',
+  [challengeTypes.backend]: 'dom',
+  [challengeTypes.zipline]: 'dom',
+  [challengeTypes.frontEndProject]: 'dom',
+  [challengeTypes.backEndProject]: 'dom',
+  [challengeTypes.pythonProject]: 'python',
+  [challengeTypes.jsProject]: 'javascript',
+  [challengeTypes.modern]: 'dom',
+  [challengeTypes.step]: 'dom',
+  [challengeTypes.quiz]: 'dom',
+  [challengeTypes.invalid]: 'dom',
+  [challengeTypes.video]: 'dom',
+  [challengeTypes.codeAllyPractice]: 'dom',
+  [challengeTypes.codeAllyCert]: 'dom',
+  [challengeTypes.multifileCertProject]: 'dom',
+  [challengeTypes.theOdinProject]: 'dom',
+  [challengeTypes.colab]: 'dom',
+  [challengeTypes.exam]: 'dom',
+  [challengeTypes.msTrophy]: 'dom',
+  [challengeTypes.multipleChoice]: 'dom',
+  [challengeTypes.python]: 'python',
+  [challengeTypes.dialogue]: 'dom',
+  [challengeTypes.fillInTheBlank]: 'dom',
+  [challengeTypes.multifilePythonCertProject]: 'python',
+  [challengeTypes.generic]: 'dom',
+  [challengeTypes.lab]: 'dom',
+  [challengeTypes.jsLab]: 'javascript',
+  [challengeTypes.pyLab]: 'python',
+  [challengeTypes.dailyChallengeJs]: 'javascript',
+  [challengeTypes.dailyChallengePy]: 'python',
+  [challengeTypes.review]: 'dom'
+};
+
+type BuildResult = {
+  challengeType: number;
+  build?: string;
+  sources: Source | undefined;
+  loadEnzyme?: boolean;
+  error?: unknown;
+};
+
+// TODO: All the buildXChallenge files have a similar structure, so make that
+// abstraction (function, class, whatever) and then create the various functions
+// out of it.
+export async function buildDOMChallenge(
+  {
+    challengeFiles,
+    required = [],
+    template = '',
+    challengeType
+  }: BuildChallengeData,
+  options?: BuildOptions
+): Promise<BuildResult> {
+  // TODO: make this required in the schema.
+  if (!challengeFiles) throw Error('No challenge files provided');
+  const hasJsx = challengeFiles.some(
+    challengeFile => challengeFile.ext === 'jsx' || challengeFile.ext === 'tsx'
+  );
+  const isMultifile = challengeFiles.length > 1;
+
+  const requiresReact16 = required.some(({ src }) =>
+    src?.includes('https://cdnjs.cloudflare.com/ajax/libs/react/16.')
+  );
+
+  // I'm reasonably sure this is fine, but we need to migrate transformers to
+  // TypeScript to be sure.
+  const transformers: ApplyFunctionProps[] = (isMultifile && hasJsx
+    ? getMultifileJSXTransformers(options)
+    : getTransformers(options)) as unknown as ApplyFunctionProps[];
+
+  const pipeLine = composeFunctions(...transformers);
+  const finalFiles = await Promise.all(challengeFiles.map(pipeLine));
+  const error = finalFiles.find(({ error }) => error)?.error;
+  const contents = (await embedFilesInHtml(finalFiles)) as string;
+
+  // if there is an error, we just build the test runner so that it can be
+  // used to run tests against the code without actually running the code.
+  const toBuild = error
+    ? {}
+    : {
+        required,
+        template,
+        contents
+      };
+
+  return {
+    challengeType,
+    build: concatHtml(toBuild),
+    sources: buildSourceMap(finalFiles),
+    loadEnzyme: requiresReact16,
+    error
+  };
+}
+
+export async function buildJSChallenge(
+  {
+    challengeFiles,
+    challengeType
+  }: { challengeFiles?: ChallengeFile[]; challengeType: number },
+  options: BuildOptions
+): Promise<BuildResult> {
+  if (!challengeFiles) throw Error('No challenge files provided');
+  const pipeLine = composeFunctions(
+    ...(getTransformers(options) as unknown as ApplyFunctionProps[])
+  );
+
+  const finalFiles = await Promise.all(challengeFiles?.map(pipeLine));
+  const error = finalFiles.find(({ error }) => error)?.error;
+
+  const toBuild = error ? [] : finalFiles;
+
+  return {
+    challengeType,
+    build: toBuild
+      .reduce(
+        (body, challengeFile) => [
+          ...body,
+          challengeFile.head,
+          challengeFile.contents,
+          challengeFile.tail
+        ],
+        [] as string[]
+      )
+      .join('\n'),
+    sources: buildSourceMap(finalFiles),
+    error
+  };
+}
+
+function buildBackendChallenge({ url, challengeType }: BuildChallengeData) {
+  return {
+    challengeType,
+    build: '',
+    sources: { contents: url }
+  };
+}
+
+export async function buildPythonChallenge({
+  challengeFiles,
+  challengeType
+}: BuildChallengeData): Promise<BuildResult> {
+  if (!challengeFiles) throw new Error('No challenge files provided');
+  const pipeLine = composeFunctions(
+    ...(getPythonTransformers() as unknown as ApplyFunctionProps[])
+  );
+  const finalFiles = await Promise.all(challengeFiles.map(pipeLine));
+  const error = finalFiles.find(({ error }) => error)?.error;
+  const sources = buildSourceMap(finalFiles);
+
+  return {
+    challengeType,
+    sources,
+    build: sources?.contents,
+    error
+  };
+}

packages/challenge-builder/src/transformers.js

@@ -17,11 +17,11 @@ import {
 } from '@freecodecamp/shared/utils/polyvinyl';
 import { version } from '@freecodecamp/browser-scripts/package.json';
 
-import { WorkerExecutor } from '../utils/worker-executor';
+import { WorkerExecutor } from './worker-executor';
 import {
   compileTypeScriptCode,
   checkTSServiceIsReady
-} from '../utils/typescript-worker-handler';
+} from './typescript-worker-handler';
 
 const protectTimeout = 100;
 const testProtectTimeout = 1500;

packages/challenge-builder/src/typescript-worker-handler.ts

@@ -1,8 +1,8 @@
-import { version } from '@freecodecamp/browser-scripts/package.json';
+import browserScripts from '@freecodecamp/browser-scripts/package.json';
 
-import { awaitResponse } from './awaitable-messenger';
+import { awaitResponse } from './awaitable-messenger.js';
 
-const typeScriptWorkerSrc = `/js/workers/${version}/typescript-worker.js`;
+const typeScriptWorkerSrc = `/js/workers/${browserScripts.version}/typescript-worker.js`;
 
 let worker: Worker | null = null;
 

packages/challenge-builder/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "include": ["src"],
+  "extends": "../../tsconfig-base.json",
+  "compilerOptions": {
+    "declaration": true,
+    "declarationMap": true,
+    "module": "es2020",
+    "moduleResolution": "bundler",
+    "outDir": "dist",
+    "noEmit": false
+  }
+}

tools/client-plugins/browser-scripts/package.json

@@ -12,6 +12,8 @@
     "dist"
   ],
   "exports": {
+    ".": "./index.d.ts",
+    "./ts-compiler": "./modules/typescript-compiler.ts",
     "./test-runner": "./test-runner.ts",
     "./package.json": "./package.json"
   },