Since v1.2.2, running ng test with source maps enabled (default) makes some bundles be loaded two times more through XHR under Chrome only

[ymeine]

Bug Report or Feature Request (mark with an x)

• bug report -> please search issues before submitting
• feature request

Versions.

@angular/cli: 1.3.1
node: 8.4.0
os: win32 x64
@angular/animations: 4.3.5
@angular/common: 4.3.5
@angular/compiler: 4.3.5
@angular/core: 4.3.5
@angular/forms: 4.3.5
@angular/http: 4.3.5
@angular/platform-browser: 4.3.5
@angular/platform-browser-dynamic: 4.3.5
@angular/router: 4.3.5
@angular/cli: 1.3.1
@angular/compiler-cli: 4.3.5
@angular/language-service: 4.3.5

Repro steps.

To reproduce the issue, run ng test on a project freshly generated by the CLI and make sure --sourcemap is enabled and that you are testing it with Chrome. Then open the developer tools and check the network panel.

The following files are all loaded three times (once through a script inclusion and then twice through XHR):

• inline.bundle.js
• vendor.bundle.js
• main.bundle.js

These are all bundles. Those additional bundles though don't suffer from this problem:

• polyfills.bundle.js
• scripts.bundle.js

The log given by the failure.

Desired functionality.

The three bundles above should be loaded only once, through script inclusion, and not at all through XHR.

Mention any other details that might be useful.

I investigated a bit more and identified commit 19f04af0777391cc72d096a0e315fe87bab161c6 as the one introducing the bug. The content changed in this commit is fairly simple, and you'll notice it concerns the source maps feature. I quickly tested removing those lines in packages/@angular/cli/plugins/karma.ts:

• 73: resolves path to newly added dependencies karma-source-map-support
• 76-77: uses the previously resolved path to actually add files into the Karma configuration

After removing those lines the bug disappears (even if I guess the source maps feature doesn't work a s expected after that.)

[vilanz]

Might cause #7296?

[clydin]

The CLI has been updated significantly since version 1.3.1. The current stable version is 8.3.5. If this problem is still being encountered with the current version, please consider opening a new issue with updated details.

[jneuhaus20]

This is still present in 8.3.6. Can we just reopen this bug? It's already triaged, has activity on it, and (arguably most importantly) this is where google brought me when I searched the issue.

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