feat: generate dynamic modules map

Author: Hyperkid123

packages/module/generate-fed-package-json.js

@@ -1,6 +1,7 @@
 const fse = require('fs-extra');
 const { globSync } = require('glob');
 const path = require('path');
+const { default: getDynamicModuleMap } = require('../../scripts/parse-dynamic-modules.mjs');
 
 const root = process.cwd();
 
@@ -60,12 +61,29 @@ async function generatePackages(files) {
   return Promise.all(cmds);
 }
 
+async function generateDynamicModuleMap() {
+  const moduleMap = getDynamicModuleMap(root);
+  // eslint-disable-next-line no-console
+  console.log('Generating dynamic module map for', Object.keys(moduleMap).length, 'modules');
+
+  if (Object.keys(moduleMap).length === 0) {
+    return Promise.resolve();
+  }
+
+  const moduleMapSorted = Object.keys(moduleMap)
+    .sort()
+    .reduce((acc, key) => ({ ...acc, [key]: moduleMap[key] }), {});
+
+  return fse.writeJSON(path.resolve(root, 'dist/dynamic-modules.json'), moduleMapSorted, { spaces: 2 });
+}
+
 async function run(files) {
   try {
     await generatePackages(files);
     if (indexTypings.length === 1) {
       copyTypings(indexTypings, root);
     }
+    await generateDynamicModuleMap();
   } catch (error) {
     // eslint-disable-next-line no-console
     console.error(error);

scripts/parse-dynamic-modules.mjs

@@ -0,0 +1,162 @@
+/* eslint-disable no-console */
+import fs from 'fs-extra';
+import { createRequire } from 'node:module';
+import path from 'node:path';
+import { glob } from 'glob';
+import ts from 'typescript';
+
+const require = createRequire(import.meta.url);
+
+/** @type {ts.CompilerOptions} */
+const tsConfigBase = require(path.resolve(import.meta.dirname, '../packages/module/tsconfig.cjs.json'));
+
+/** @type {ts.CompilerOptions} */
+const defaultCompilerOptions = {
+  target: tsConfigBase.target,
+  module: tsConfigBase.module,
+  moduleResolution: tsConfigBase.moduleResolution,
+  esModuleInterop: tsConfigBase.esModuleInterop,
+  allowJs: true,
+  strict: false,
+  skipLibCheck: true,
+  noEmit: true
+};
+
+/**
+ * Map all exports of the given index module to their corresponding dynamic modules.
+ *
+ * Example: `@patternfly/react-core` package provides ESModules index at `dist/esm/index.js`
+ * which exports Alert component related code & types via `dist/esm/components/Alert/index.js`
+ * module.
+ *
+ * Given the example above, this function should return a mapping like so:
+ * ```js
+ * {
+ *   Alert: 'dist/dynamic/components/Alert',
+ *   AlertProps: 'dist/dynamic/components/Alert',
+ *   AlertContext: 'dist/dynamic/components/Alert',
+ *   // ...
+ * }
+ * ```
+ *
+ * The above mapping can be used when generating import statements like so:
+ * ```ts
+ * import { Alert } from '@patternfly/react-core/dist/dynamic/components/Alert';
+ * ```
+ *
+ * It may happen that the same export is provided by multiple dynamic modules;
+ * in such case, the resolution favors modules with most specific file paths, for example
+ * `dist/dynamic/components/Wizard/hooks` is favored over `dist/dynamic/components/Wizard`.
+ *
+ * Dynamic modules nested under `deprecated` or `next` directories are ignored.
+ *
+ * If the referenced index module does not exist, an empty object is returned.
+ *
+ * @param {string} basePath
+ * @param {string} indexModule
+ * @param {string} resolutionField
+ * @param {ts.CompilerOptions} tsCompilerOptions
+ * @returns {Record<string, string>}
+ */
+const getDynamicModuleMap = (
+  basePath,
+  indexModule = 'dist/esm/index.js',
+  resolutionField = 'module',
+  tsCompilerOptions = defaultCompilerOptions
+) => {
+  if (!path.isAbsolute(basePath)) {
+    throw new Error('Package base path must be absolute');
+  }
+
+  const indexModulePath = path.resolve(basePath, indexModule);
+
+  if (!fs.existsSync(indexModulePath)) {
+    return {};
+  }
+
+  /** @type {Record<string, string>} */
+  const dynamicModulePathToPkgDir = glob.sync(`${basePath}/dist/dynamic/**/package.json`).reduce((acc, pkgFile) => {
+    const pkg = require(pkgFile);
+    const pkgModule = pkg[resolutionField];
+
+    if (!pkgModule) {
+      throw new Error(`Missing field ${resolutionField} in ${pkgFile}`);
+    }
+
+    const pkgResolvedPath = path.resolve(path.dirname(pkgFile), pkgModule);
+    const pkgRelativePath = path.dirname(path.relative(basePath, pkgFile));
+
+    acc[pkgResolvedPath] = pkgRelativePath;
+
+    return acc;
+  }, {});
+
+  const dynamicModulePaths = Object.keys(dynamicModulePathToPkgDir);
+  const compilerHost = ts.createCompilerHost(tsCompilerOptions);
+  const program = ts.createProgram([indexModulePath, ...dynamicModulePaths], tsCompilerOptions, compilerHost);
+  const errorDiagnostics = ts.getPreEmitDiagnostics(program).filter((d) => d.category === ts.DiagnosticCategory.Error);
+
+  if (errorDiagnostics.length > 0) {
+    const { getCanonicalFileName, getCurrentDirectory, getNewLine } = compilerHost;
+
+    console.error(
+      ts.formatDiagnostics(errorDiagnostics, {
+        getCanonicalFileName,
+        getCurrentDirectory,
+        getNewLine
+      })
+    );
+
+    throw new Error(`Detected TypeScript errors while parsing modules at ${basePath}`);
+  }
+
+  const typeChecker = program.getTypeChecker();
+
+  /** @param {ts.SourceFile} sourceFile */
+  const getExportNames = (sourceFile) =>
+    typeChecker.getExportsOfModule(typeChecker.getSymbolAtLocation(sourceFile)).map((symbol) => symbol.getName());
+
+  const indexModuleExports = getExportNames(program.getSourceFile(indexModulePath));
+
+  /** @type {Record<string, string[]>} */
+  const dynamicModuleExports = dynamicModulePaths.reduce((acc, modulePath) => {
+    acc[modulePath] = getExportNames(program.getSourceFile(modulePath));
+    return acc;
+  }, {});
+
+  /** @param {string[]} modulePaths */
+  const getMostSpecificModulePath = (modulePaths) =>
+    modulePaths.reduce((acc, p) => {
+      const pathSpecificity = p.split(path.sep).length;
+      const currSpecificity = acc.split(path.sep).length;
+
+      if (pathSpecificity > currSpecificity) {
+        return p;
+      }
+
+      if (pathSpecificity === currSpecificity) {
+        return !p.endsWith('index.js') && acc.endsWith('index.js') ? p : acc;
+      }
+
+      return acc;
+    }, '');
+
+  return indexModuleExports.reduce((acc, exportName) => {
+    const foundModulePaths = Object.keys(dynamicModuleExports).filter((modulePath) =>
+      dynamicModuleExports[modulePath].includes(exportName)
+    );
+
+    const filteredModulePaths = foundModulePaths.filter((modulePath) => {
+      const dirNames = path.dirname(modulePath).split(path.sep);
+      return !dirNames.includes('deprecated') && !dirNames.includes('next');
+    });
+
+    if (filteredModulePaths.length > 0) {
+      acc[exportName] = dynamicModulePathToPkgDir[getMostSpecificModulePath(filteredModulePaths)];
+    }
+
+    return acc;
+  }, {});
+};
+
+export default getDynamicModuleMap;