fix(@angular-devkit/build-angular): emit error when a script is not found

While we currently invoke the `callback` with the error in https://github.com/angular/angular-cli/blob/d4f1ff82c5d994aca68c39ff31f5d8b22e694b87/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/scripts-webpack-plugin.ts#L163 this is not bubbled up to the main webpack compilation due to the usage of `thisCompilation`.

Closes #16659

Author: alan-agius4

packages/angular_devkit/build_angular/src/angular-cli-files/models/webpack-configs/common.ts

@@ -11,6 +11,7 @@ import {
 } from '@angular-devkit/build-optimizer';
 import { tags } from '@angular-devkit/core';
 import * as CopyWebpackPlugin from 'copy-webpack-plugin';
+import { existsSync } from 'fs';
 import * as path from 'path';
 import { RollupOptions } from 'rollup';
 import { ScriptTarget } from 'typescript';
@@ -214,23 +215,28 @@ export function getCommonConfig(wco: WebpackConfigOptions): Configuration {
     buildOptions.scripts,
     'scripts',
   ).reduce((prev: { bundleName: string; paths: string[]; inject: boolean }[], curr) => {
-    const bundleName = curr.bundleName;
-    const resolvedPath = path.resolve(root, curr.input);
+    const { bundleName, inject, input } = curr;
+    const resolvedPath = path.resolve(root, input);
+
+    if (!existsSync(resolvedPath)) {
+      throw new Error(`Script file ${input} does not exist.`);
+    }
+
     const existingEntry = prev.find(el => el.bundleName === bundleName);
     if (existingEntry) {
-      if (existingEntry.inject && !curr.inject) {
+      if (existingEntry.inject && !inject) {
         // All entries have to be lazy for the bundle to be lazy.
         throw new Error(
-          `The ${curr.bundleName} bundle is mixing injected and non-injected scripts.`,
+          `The ${bundleName} bundle is mixing injected and non-injected scripts.`,
         );
       }
 
       existingEntry.paths.push(resolvedPath);
     } else {
       prev.push({
         bundleName,
+        inject,
         paths: [resolvedPath],
-        inject: curr.inject,
       });
     }
 

packages/angular_devkit/build_angular/test/browser/scripts-array_spec_large.ts

@@ -175,4 +175,16 @@ describe('Browser Builder scripts array', () => {
     expect(logs.join('\n')).toMatch(/\(renamed-script\) 78 bytes.*\[entry].*\[rendered]/);
     expect(logs.join('\n')).toMatch(/\(renamed-lazy-script\) 88 bytes.*\[entry].*\[rendered]/);
   });
+
+  it(`should error when a script doesn't exist`, async () => {
+    await expectAsync(browserBuild(
+      architect,
+      host,
+      target,
+      {
+        scripts: ['./invalid.js'],
+      },
+    ))
+      .toBeRejectedWithError(`Script file ./invalid.js does not exist.`);
+  });
 });