Merge pull request #2444 from xia-chao/fix/monorepo-alias-esm

fix(monorepo): resolve ESM path aliases and project rootDir

Author: kamilmysliwiec

src/lib/library/files/ts/tsconfig.lib.json

@@ -1,9 +1,8 @@
 {
   "extends": "../../tsconfig.json",
   "compilerOptions": {
-    "composite": true,
     "declaration": true,
-    "rootDir": "./src",
+    "rootDir": "../..",
     "outDir": "../../dist/libs/<%= name %>"
   },
   "include": ["src/**/*"],

src/lib/library/library.factory.ts

@@ -19,6 +19,7 @@ import { formatFiles } from '../../utils/format-files.rule.js';
 import {
   createModuleNameMapper,
   inPlaceSortByKeys,
+  NEST_CLI_CONFIG_FILES,
   normalizeToKebabOrSnakeCase,
 } from '../../utils/index.js';
 import {
@@ -59,12 +60,9 @@ export function main(options: LibraryOptions): Rule {
 
 function getDefaultLibraryPrefix(defaultLibraryPrefix = '@app') {
   const fileSystemReader = new FileSystemReader(process.cwd());
-  const content: string | undefined = fileSystemReader.readSyncAnyOf([
-    'nest-cli.json',
-    '.nestcli.json',
-    '.nest-cli.json',
-    'nest.json',
-  ]);
+  const content: string | undefined = fileSystemReader.readSyncAnyOf(
+    NEST_CLI_CONFIG_FILES,
+  );
 
   try {
     const nestJson = JSON.parse(content || '{}');
@@ -235,6 +233,10 @@ function updateTsConfig(
     const packageKey = packagePrefix
       ? packagePrefix + '/' + packageName
       : packageName;
+    // ESM performs no directory-index resolution, so the alias has to name the
+    // entry file; CommonJS keeps resolving `./libs/x/src` through index.*.
+    const aliasTarget =
+      './' + distRoot + (isEsmProject(host) ? '/index.ts' : '');
 
     return updateJsonFile(
       host,
@@ -250,7 +252,7 @@ function updateTsConfig(
         if (!tsconfig.compilerOptions.paths[packageKey]) {
           tsconfig.compilerOptions.paths[packageKey] = [];
         }
-        tsconfig.compilerOptions.paths[packageKey].push('./' + distRoot);
+        tsconfig.compilerOptions.paths[packageKey].push(aliasTarget);
 
         const deepPackagePath = packageKey + '/*';
         if (!tsconfig.compilerOptions.paths[deepPackagePath]) {

src/lib/sub-app/files/ts/tsconfig.app.json

@@ -1,9 +1,8 @@
 {
   "extends": "../../tsconfig.json",
   "compilerOptions": {
-    "composite": true,
-    "declaration": true,
-    "rootDir": "./src",
+    "declaration": false,
+    "rootDir": "../..",
     "outDir": "../../dist/apps/<%= name %>"
   },
   "include": ["src/**/*"],

src/lib/sub-app/sub-app.factory.ts

@@ -19,8 +19,10 @@ import { existsSync, readFileSync } from 'fs';
 import { parse, stringify } from 'comment-json';
 import { formatFiles } from '../../utils/format-files.rule.js';
 import {
+  findNestCliConfigPath,
   inPlaceSortByKeys,
   normalizeToKebabOrSnakeCase,
+  readJsonFile,
 } from '../../utils/index.js';
 import {
   DEFAULT_APPS_PATH,
@@ -35,6 +37,12 @@ import {
 import type { SubAppOptions } from './sub-app.schema.js';
 import { isEsmProject } from '../../utils/source-root.helpers.js';
 
+/** The builder `nest g app` writes when it converts a workspace to a monorepo. */
+const DEFAULT_BUILDER = 'rspack';
+
+/** What the CLI itself assumes when `nest-cli.json` names no builder. */
+const CLI_DEFAULT_BUILDER = 'tsc';
+
 type UpdateJsonFn<T> = (obj: T) => T | void;
 interface TsConfigPartialType {
   compilerOptions?: Record<string, any>;
@@ -59,6 +67,7 @@ export function main(options: SubAppOptions): Rule {
           ])(tree, context),
     addAppsToCliOptions(options.path!, options.name, appName),
     addTsConfigReference(options.path!, options.name),
+    applyStartProdScript(options, appName),
     (tree) => {
       (options as any).isEsm = isEsmProject(tree);
       return tree;
@@ -228,6 +237,34 @@ function updatePackageJson(options: SubAppOptions, defaultAppName: string) {
   };
 }
 
+type BuilderConfig = { compilerOptions?: { builder?: unknown } };
+
+/**
+ * Reads the builder in use. `builder` is either a name or a `{ type }` object,
+ * and the CLI falls back to `tsc` when it is absent - which only happens in a
+ * workspace that was already a monorepo, since the conversion writes one.
+ */
+function readBuilder(host: Tree): string {
+  const path = findNestCliConfigPath(host);
+  const config = path ? readJsonFile<BuilderConfig>(host, path) : null;
+  const builder = config?.compilerOptions?.builder;
+  const name =
+    typeof builder === 'string'
+      ? builder
+      : (builder as { type?: unknown } | undefined)?.type;
+  return typeof name === 'string' && name ? name : CLI_DEFAULT_BUILDER;
+}
+
+/**
+ * Builders that emit one bundle per project rather than mirroring the source
+ * tree into `outDir`. Everything else - `tsc`, and `swc`, whose
+ * `stripLeadingPaths` is off whenever `rootDir` sits above the source root -
+ * writes the nested `dist/<root>/<root>/src/main.js` entry.
+ */
+function isBundler(builder: string): boolean {
+  return builder === 'rspack' || builder === 'webpack';
+}
+
 function updateNpmScripts(
   scripts: Record<string, any>,
   options: SubAppOptions,
@@ -237,13 +274,8 @@ function updateNpmScripts(
     return;
   }
   const defaultFormatScriptName = 'format';
-  const defaultStartScriptName = 'start:prod';
   const defaultTestScriptName = 'test:e2e';
-  if (
-    !scripts[defaultTestScriptName] &&
-    !scripts[defaultFormatScriptName] &&
-    !scripts[defaultStartScriptName]
-  ) {
+  if (!scripts[defaultTestScriptName] && !scripts[defaultFormatScriptName]) {
     return;
   }
   if (
@@ -269,15 +301,49 @@ function updateNpmScripts(
     scripts[defaultFormatScriptName] =
       `prettier --write "${defaultSourceRoot}/**/*.ts" "${DEFAULT_LIB_PATH}/**/*.ts"`;
   }
-  if (
-    scripts[defaultStartScriptName] &&
-    scripts[defaultStartScriptName].indexOf('dist/main') >= 0
-  ) {
-    const defaultSourceRoot =
-      options.rootDir !== undefined ? options.rootDir : DEFAULT_APPS_PATH;
-    scripts[defaultStartScriptName] =
-      `node dist/${defaultSourceRoot}/${defaultAppName}/main`;
-  }
+}
+
+/**
+ * Writes `start:prod` for the builder the workspace ends up using. This has to
+ * run after the CLI options are final: `nest g app` forces `rspack` when it
+ * converts a single app into a monorepo, so reading the builder earlier would
+ * write a script that does not match the final config.
+ */
+function applyStartProdScript(
+  options: SubAppOptions,
+  defaultAppName: string,
+): Rule {
+  return (host: Tree) => {
+    if (!host.exists('package.json')) {
+      return host;
+    }
+    const builder = readBuilder(host);
+    return updateJsonFile(
+      host,
+      'package.json',
+      (packageJson: Record<string, Record<string, any>>) => {
+        const scripts = packageJson.scripts;
+        const startScript = scripts?.['start:prod'];
+        if (
+          typeof startScript !== 'string' ||
+          !/^node dist\/(.+\/)?main$/.test(startScript)
+        ) {
+          return;
+        }
+        const defaultSourceRoot =
+          options.rootDir !== undefined ? options.rootDir : DEFAULT_APPS_PATH;
+        // A bundler ignores `rootDir` and writes `dist/<root>/main.js`, which
+        // is also where `nest start` falls back to looking. A per-file
+        // compiler mirrors the source tree under `rootDir` (the workspace
+        // root) into the project's `outDir`, so the project path appears
+        // twice: dist/apps/<app>/apps/<app>/src/main.
+        const projectRoot = `${defaultSourceRoot}/${defaultAppName}`;
+        scripts['start:prod'] = isBundler(builder)
+          ? `node dist/${projectRoot}/main`
+          : `node dist/${projectRoot}/${projectRoot}/src/main`;
+      },
+    );
+  };
 }
 
 function updateJestOptions(
@@ -411,7 +477,7 @@ function updateMainAppOptions(
   if (!optionsFile.compilerOptions) {
     optionsFile.compilerOptions = {};
   }
-  optionsFile.compilerOptions.builder = 'rspack';
+  optionsFile.compilerOptions.builder = DEFAULT_BUILDER;
   optionsFile.compilerOptions.tsConfigPath = tsConfigPath;
 
   if (!optionsFile.projects) {

src/lib/sub-app/workspace/ts/tsconfig.app.json

@@ -1,9 +1,8 @@
 {
   "extends": "../../tsconfig.json",
   "compilerOptions": {
-    "composite": true,
-    "declaration": true,
-    "rootDir": "./src",
+    "declaration": false,
+    "rootDir": "../..",
     "outDir": "../../dist/apps/<%= name %>"
   },
   "include": ["src/**/*"],

src/lib/upgrade/upgrade.utils.ts

@@ -1,5 +1,4 @@
 import { SchematicContext, Tree } from '@angular-devkit/schematics';
-import { parse } from 'jsonc-parser';
 import type {
   Node,
   ObjectLiteralElementLike,
@@ -16,11 +15,18 @@ import {
   isStringLiteral,
 } from 'typescript';
 import { JSONFile } from '../../utils/json-file.util.js';
+import {
+  findNestCliConfigPath,
+  readJsonFile,
+} from '../../utils/nest-cli-config.util.js';
 import {
   getPackageJsonDependency,
   NodeDependencyType,
 } from '../../utils/dependencies.utils.js';
 
+// Re-exported so existing `upgrade.utils.js` consumers keep working.
+export { findNestCliConfigPath, readJsonFile };
+
 export const MIGRATION_GUIDE_URL = 'https://docs.nestjs.com/migration-guide';
 
 export interface TextEdit {
@@ -114,21 +120,6 @@ export function parseVersion(version: string): number[] {
   return match ? [Number(match[1]), Number(match[2]), Number(match[3])] : [];
 }
 
-export function readJsonFile<T = Record<string, any>>(
-  tree: Tree,
-  path: string,
-): T | null {
-  const buffer = tree.read(path);
-  if (!buffer) {
-    return null;
-  }
-  try {
-    return parse(buffer.toString('utf-8')) as T;
-  } catch {
-    return null;
-  }
-}
-
 export function readPackageJson(tree: Tree): Record<string, any> | null {
   return readJsonFile(tree, 'package.json');
 }
@@ -146,17 +137,6 @@ export interface NestCliConfig {
   projects: Record<string, NestCliProject>;
 }
 
-const NEST_CLI_CONFIG_FILES = [
-  'nest-cli.json',
-  '.nestcli.json',
-  '.nest-cli.json',
-  'nest.json',
-];
-
-export function findNestCliConfigPath(tree: Tree): string | undefined {
-  return NEST_CLI_CONFIG_FILES.find((candidate) => tree.exists(candidate));
-}
-
 export function readNestCliConfig(tree: Tree): NestCliConfig {
   const path = findNestCliConfigPath(tree);
   const config = path ? (readJsonFile(tree, path) ?? {}) : {};

src/utils/index.ts

@@ -10,3 +10,4 @@ export * from './source-root.helpers.js';
 export * from './formatting.js';
 export * from './jest-module-mapper.js';
 export * from './object-sorting.js';
+export * from './nest-cli-config.util.js';

src/utils/nest-cli-config.util.ts

@@ -0,0 +1,36 @@
+import { Tree } from '@angular-devkit/schematics';
+import { parse } from 'jsonc-parser';
+
+/**
+ * The config file names the CLI looks for, in the order it tries them.
+ */
+export const NEST_CLI_CONFIG_FILES = [
+  'nest-cli.json',
+  '.nestcli.json',
+  '.nest-cli.json',
+  'nest.json',
+];
+
+/**
+ * Resolves the Nest CLI config file in use. The CLI loads the first file that
+ * exists and ignores the remaining candidates, so a config without a `builder`
+ * is not overridden by a later file.
+ */
+export function findNestCliConfigPath(tree: Tree): string | undefined {
+  return NEST_CLI_CONFIG_FILES.find((candidate) => tree.exists(candidate));
+}
+
+export function readJsonFile<T = Record<string, any>>(
+  tree: Tree,
+  path: string,
+): T | null {
+  const buffer = tree.read(path);
+  if (!buffer) {
+    return null;
+  }
+  try {
+    return parse(buffer.toString('utf-8')) as T;
+  } catch {
+    return null;
+  }
+}