Angular CLI incorrectly loads jasmine-core as an ES module

Start with the Angular CLI Karma polyfill at packages/angular/build/src/builders/karma/polyfills/jasmine_global.js and the changes introduced by pull request 29104. Reproduce the issue with the listed ng new and npm t steps, then inspect the generated jasmine.js script tag. Done means jasmine-core is no longer loaded as an ES module and the existing Karma test flow still works.

Command

new, 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

Likely 19.0.x

Description

Note: I maintain Jasmine.

jasmine-core is a plain old script/CommonJS hybrid, not an ES module, but the Angular dev tools load it via <script type="module">. That appears to be the cause of the global this problems that the angular CLI works around by monkey patching the window object to look like it's from an old version of the GJS runtime. It could cause other problems as well.

https://github.com/angular/angular-cli/pull/29104 appears to have introduced both the bug and the GJS workaround.

jasmine-core 6.x will use globalThis to find the global object, which should do away with the need for the GJS workaround. But it will also emit a warning if it's loaded as an ES module in the browser, since that's an unsupported and un-tested configuration that's already known to have caused problems.

Minimal Reproduction

1. Run ng new and accept the defaults. (I used @angular/cli 20.3.5.)
2. In the created project, run npm t.
3. Click the debug button in Karma.
4. View source in the resulting tab.
5. Look for the script tag that loads jasmine.js.

If you want to see the warning:

1. Run ng new and select the zoneless option. This isn't strictly necessary but it will avoid errors related to jasmine/jasmine#2078.
2. Patch package.json as shown below.
3. Remove package-lock.json and node_modules.
4. Run npm install.
5. Run npm t.

diff --git a/package.json b/package.json
index 0474f8f..2fff3a9 100644
--- a/package.json
+++ b/package.json
@@ -37,12 +37,20 @@
     "@angular/cli": "^20.3.5",
     "@angular/compiler-cli": "^20.3.0",
     "@types/jasmine": "~5.1.0",
-    "jasmine-core": "~5.9.0",
+    "jasmine-core": "github:jasmine/jasmine#6.0",
     "karma": "~6.4.0",
     "karma-chrome-launcher": "~3.2.0",
     "karma-coverage": "~2.2.0",
     "karma-jasmine": "~5.1.0",
     "karma-jasmine-html-reporter": "~2.1.0",
     "typescript": "~5.9.2"
+  },
+  "overrides": {
+    "karma-jasmine": {
+      "jasmine-core": "6.0.0-alpha.0"
+    },
+    "karma-jasmine-html-reporter": {
+      "jasmine-core": "6.0.0-alpha.0"
+    }
   }
-}
\ No newline at end of file
+}

Exception or Error

Your Environment

_                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    


Angular CLI: 20.3.5
Node: 20.19.0
Package Manager: npm 10.8.2
OS: darwin arm64
    

Angular: 20.3.4
... common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                      Version
------------------------------------
@angular-devkit/architect    0.2003.5
@angular-devkit/core         20.3.5
@angular-devkit/schematics   20.3.5
@angular/build               20.3.5
@angular/cli                 20.3.5
@schematics/angular          20.3.5
rxjs                         7.8.2
typescript                   5.9.3
zone.js                      0.15.1

Anything else relevant?

No response