refactor(@angular/cli): use custom scoped require instead of global

To support the eventual conversion of the `@angular/cli` package to ESM, the usage of the global require function must be removed as it is not supported in ESM code. Node.js does have the facility to create custom require functions that can be used when the need to synchronously load a file at runtime is required. Such cases have now been converted to use custom require functions where appropriate.

Author: clydin

packages/angular/cli/commands/version-impl.ts

@@ -7,7 +7,7 @@
  */
 
 import { execSync } from 'child_process';
-import * as path from 'path';
+import nodeModule from 'module';
 import { Command } from '../models/command';
 import { colors } from '../utilities/color';
 import { getPackageManager } from '../utilities/package-manager';
@@ -28,11 +28,15 @@ interface PartialPackageInfo {
 export class VersionCommand extends Command<VersionCommandSchema> {
   public static aliases = ['v'];
 
+  private readonly localRequire = nodeModule.createRequire(__filename);
+  // Trailing slash is used to allow the path to be treated as a directory
+  private readonly workspaceRequire = nodeModule.createRequire(this.context.root + '/');
+
   async run() {
-    const cliPackage: PartialPackageInfo = require('../package.json');
+    const cliPackage: PartialPackageInfo = this.localRequire('../package.json');
     let workspacePackage: PartialPackageInfo | undefined;
     try {
-      workspacePackage = require(path.resolve(this.context.root, 'package.json'));
+      workspacePackage = this.workspaceRequire('./package.json');
     } catch {}
 
     const [nodeMajor] = process.versions.node.split('.').map((part) => Number(part));
@@ -151,28 +155,28 @@ export class VersionCommand extends Command<VersionCommandSchema> {
   }
 
   private getVersion(moduleName: string): string {
-    let packagePath;
+    let packageInfo: PartialPackageInfo | undefined;
     let cliOnly = false;
 
     // Try to find the package in the workspace
     try {
-      packagePath = require.resolve(`${moduleName}/package.json`, { paths: [this.context.root] });
+      packageInfo = this.workspaceRequire(`${moduleName}/package.json`);
     } catch {}
 
     // If not found, try to find within the CLI
-    if (!packagePath) {
+    if (!packageInfo) {
       try {
-        packagePath = require.resolve(`${moduleName}/package.json`);
+        packageInfo = this.localRequire(`${moduleName}/package.json`);
         cliOnly = true;
       } catch {}
     }
 
     let version: string | undefined;
 
     // If found, attempt to get the version
-    if (packagePath) {
+    if (packageInfo) {
       try {
-        version = require(packagePath).version + (cliOnly ? ' (cli-only)' : '');
+        version = packageInfo.version + (cliOnly ? ' (cli-only)' : '');
       } catch {}
     }
 

packages/angular/cli/models/schematic-engine-host.ts

@@ -121,7 +121,8 @@ function wrap(
   moduleCache: Map<string, unknown>,
   exportName?: string,
 ): () => unknown {
-  const scopedRequire = nodeModule.createRequire(schematicFile);
+  const hostRequire = nodeModule.createRequire(__filename);
+  const schematicRequire = nodeModule.createRequire(schematicFile);
 
   const customRequire = function (id: string) {
     if (legacyModules[id]) {
@@ -131,13 +132,13 @@ function wrap(
       // Resolve from inside the `@angular/cli` project
       const packagePath = require.resolve(id);
 
-      return require(packagePath);
+      return hostRequire(packagePath);
     } else if (id.startsWith('.') || id.startsWith('@angular/cdk')) {
       // Wrap relative files inside the schematic collection
       // Also wrap `@angular/cdk`, it contains helper utilities that import core schematic packages
 
       // Resolve from the original file
-      const modulePath = scopedRequire.resolve(id);
+      const modulePath = schematicRequire.resolve(id);
 
       // Use cached module if available
       const cachedModule = moduleCache.get(modulePath);
@@ -159,7 +160,7 @@ function wrap(
     }
 
     // All others are required directly from the original file
-    return scopedRequire(id);
+    return schematicRequire(id);
   };
 
   // Setup a wrapper function to capture the module's exports