Reproduction

This applies for the example that use test harness for all material components (except for ripples).

Steps to reproduce:

1. Open the StackBlitz link for examples that have tests using a test harness in the 'Examples' page.

Expected Behavior

A working StackBlitz link for these examples. The examples in the documentation site for v11 work as expected (working example for tree component).

Actual Behavior

The StackBlitz link for v12 documentation for test harnesses show an error (failing example for tree component).

The error is the same for all:

Could not find a declaration file for module 'jasmine-core/lib/jasmine-core/jasmine.js'. '/turbo_modules/jasmine-core@3.7.1/lib/jasmine-core/jasmine.js' implicitly has an 'any' type.
Try `npm i --save-dev @types/jasmine-core` if it exists or add a new declaration (.d.ts) file containing `declare module 'jasmine-core/lib/jasmine-core/jasmine.js';`

Environment

• Angular: ^12.0.0
• CDK/Material: ^12.0.0
• Browser(s): Chrome 90
• Operating System (e.g. Windows, macOS, Ubuntu): macOS