feat(js): infer tslib as a dependency when using importHelpers

e2e/js/src/js.test.ts

@@ -5,7 +5,6 @@ import {
   readJson,
   runCLI,
   runCLIAsync,
-  runCommand,
   runCommandUntil,
   uniq,
   updateFile,
@@ -14,8 +13,13 @@ import {
 } from '../../utils';
 
 describe('js e2e', () => {
+  let scope: string;
+
+  beforeEach(() => {
+    scope = newProject();
+  });
+
   it('should create libs with npm scripts', () => {
-    const scope = newProject();
     const npmScriptsLib = uniq('npmscriptslib');
     runCLI(`generate @nrwl/js:lib ${npmScriptsLib} --config=npm-scripts`);
     const libPackageJson = readJson(`libs/${npmScriptsLib}/package.json`);
@@ -31,7 +35,6 @@ describe('js e2e', () => {
   }, 120000);
 
   it('should create libs with js executors (--compiler=tsc)', async () => {
-    const scope = newProject();
     const lib = uniq('lib');
     runCLI(`generate @nrwl/js:lib ${lib} --buildable --compiler=tsc`);
     const libPackageJson = readJson(`libs/${lib}/package.json`);
@@ -123,10 +126,35 @@ describe('js e2e', () => {
     const output = runCLI(`build ${parentLib}`);
     expect(output).toContain('1 task(s) it depends on');
     expect(output).toContain('Done compiling TypeScript files');
+
+    updateJson(`libs/${lib}/tsconfig.json`, (json) => {
+      json.compilerOptions = { ...json.compilerOptions, importHelpers: true };
+      return json;
+    });
+
+    runCLI(`build ${lib}`);
+
+    const rootPackageJson = readJson(`package.json`);
+
+    expect(readJson(`dist/libs/${lib}/package.json`)).toHaveProperty(
+      'peerDependencies.tslib',
+      rootPackageJson.dependencies.tslib ??
+        rootPackageJson.devDependencies.tslib
+    );
+
+    updateJson(`libs/${lib}/tsconfig.json`, (json) => {
+      json.compilerOptions = { ...json.compilerOptions, importHelpers: false };
+      return json;
+    });
+
+    runCLI(`build ${lib}`);
+
+    expect(readJson(`dist/libs/${lib}/package.json`)).not.toHaveProperty(
+      'peerDependencies.tslib'
+    );
   }, 120000);
 
   it('should create libs with js executors (--compiler=swc)', async () => {
-    const scope = newProject();
     const lib = uniq('lib');
     runCLI(`generate @nrwl/js:lib ${lib} --buildable --compiler=swc`);
     const libPackageJson = readJson(`libs/${lib}/package.json`);

packages/js/src/executors/tsc/tsc.impl.ts

@@ -7,6 +7,7 @@ import { join, resolve } from 'path';
 import { checkDependencies } from '../../utils/check-dependencies';
 import { CopyAssetsHandler } from '../../utils/copy-assets-handler';
 import { ExecutorOptions, NormalizedExecutorOptions } from '../../utils/schema';
+import { addTslibDependencyIfNeeded } from '../../utils/tslib-dependency';
 import { compileTypeScriptFiles } from '../../utils/typescript/compile-typescript-files';
 import { updatePackageJson } from '../../utils/update-package-json';
 import { watchForSingleFileChanges } from '../../utils/watch-for-single-file-changes';
@@ -60,6 +61,8 @@ export async function* tscExecutor(
     options.tsConfig = tmpTsConfig;
   }
 
+  addTslibDependencyIfNeeded(options, context, dependencies);
+
   const assetHandler = new CopyAssetsHandler({
     projectDir: projectRoot,
     rootDir: context.root,

packages/js/src/utils/tslib-dependency.ts

@@ -0,0 +1,47 @@
+import { ExecutorContext, getPackageManagerCommand } from '@nrwl/devkit';
+import { readCachedProjectGraph } from '@nrwl/workspace/src/core/project-graph';
+import { DependentBuildableProjectNode } from '@nrwl/workspace/src/utilities/buildable-libs-utils';
+import { readTsConfig } from '@nrwl/workspace/src/utilities/typescript';
+import { NormalizedExecutorOptions } from './schema';
+
+const tslibNodeName = 'npm:tslib';
+
+function shouldAddTslibDependency(
+  tsConfig: string,
+  dependencies: DependentBuildableProjectNode[]
+): boolean {
+  if (dependencies.some((dep) => dep.name === tslibNodeName)) {
+    return false;
+  }
+
+  const config = readTsConfig(tsConfig);
+  return !!config.options.importHelpers;
+}
+
+export function addTslibDependencyIfNeeded(
+  options: NormalizedExecutorOptions,
+  context: ExecutorContext,
+  dependencies: DependentBuildableProjectNode[]
+): void {
+  if (!shouldAddTslibDependency(options.tsConfig, dependencies)) {
+    return;
+  }
+
+  const depGraph = readCachedProjectGraph();
+  const tslibNode = depGraph.externalNodes[tslibNodeName];
+
+  if (!tslibNode) {
+    const pmc = getPackageManagerCommand();
+    throw new Error(
+      `"importHelpers" is enabled for ${context.targetName} but tslib is not installed. Use "${pmc.add} tslib" to install it.`
+    );
+  }
+
+  const tslibDependency: DependentBuildableProjectNode = {
+    name: tslibNodeName,
+    outputs: [],
+    node: tslibNode,
+  };
+
+  dependencies.push(tslibDependency);
+}

packages/workspace/src/utilities/typescript.ts

@@ -10,7 +10,7 @@ export { getSourceNodes } from './typescript/get-source-nodes';
 
 const normalizedAppRoot = appRootPath.replace(/\\/g, '/');
 
-let tsModule: any;
+let tsModule: typeof import('typescript');
 
 export function readTsConfig(tsConfigPath: string) {
   if (!tsModule) {
@@ -31,18 +31,21 @@ function readTsConfigOptions(tsConfigPath: string) {
   if (!tsModule) {
     tsModule = require('typescript');
   }
+
   const readResult = tsModule.readConfigFile(
     tsConfigPath,
     tsModule.sys.readFile
   );
+
   // we don't need to scan the files, we only care about options
-  const host = {
+  const host: Partial<ts.ParseConfigHost> = {
     readDirectory: () => [],
     fileExists: tsModule.sys.fileExists,
   };
+
   return tsModule.parseJsonConfigFileContent(
     readResult.config,
-    host,
+    host as ts.ParseConfigHost,
     dirname(tsConfigPath)
   ).options;
 }