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

When using "importHelpers" and building with "tsc", the built bundle expects to be supplied the
"tslib" package.

Currently, it's up to developers to add "tslib" as a dependency to those
libraries' package.json files.

This PR makes the "tsc" execute infer that "importHelpers" is used,
and subsequently add "tslib" as a dependency to the generated package.json

ISSUES CLOSED: #9343

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;
 }