Style path error in test configuration logs an obscure error message

[cexbrayat]

Command

test

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

In a new project, replace styles.css by a file that does not exists:

- "styles": ["src/styles.css"],
+ "styles": ["src/error.css"],

then run ng test

Minimal Reproduction

https://stackblitz.com/edit/node-8w6owh?file=repro-style-error/angular.json

Run ng test

Exception or Error

❯ ng test
⠙ Generating browser application bundles (phase: setup)...AssertionError [ERR_ASSERTION] [ERR_ASSERTION]: Compilation cannot be undefined.
    at get (https://node8w6owh-vb42.w-corp.staticblitz.com/blitz.8cf5a3c77f45c942df800a39619ec49fff7e5814.js:6:292488)
    at AssertionError (https://node8w6owh-vb42.w-corp.staticblitz.com/blitz.8cf5a3c77f45c942df800a39619ec49fff7e5814.js:6:944835)
    at innerOk (https://node8w6owh-vb42.w-corp.staticblitz.com/blitz.8cf5a3c77f45c942df800a39619ec49fff7e5814.js:6:827492)
    at ok (https://node8w6owh-vb42.w-corp.staticblitz.com/blitz.8cf5a3c77f45c942df800a39619ec49fff7e5814.js:6:827616)
    at apply/webpackOptions.entry@file:///home/projects/node-8w6owh/repro-style-error/node_modules/ (angular-devkit/build-angular/src/webpack/plugins/styles-webpack-plugin.js:58:46)
    at <anonymous> (<anonymous>) {
  generatedMessage: false,
  code: 'ERR_ASSERTION',
  actual: undefined,
  expected: true,
  operator: '=='
}

Your Environment

Angular CLI: 15.0.3
Node: 16.14.2
Package Manager: npm 7.17.0
OS: linux x64

Angular: 15.0.3
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1500.3
@angular-devkit/build-angular   15.0.3
@angular-devkit/core            15.0.3
@angular-devkit/schematics      15.0.3
@schematics/angular             15.0.3
rxjs                            7.5.7
typescript                      4.8.4

Anything else relevant?

No response