Proposal: Improve Test Results Output for AI and Manual Debugging

[GermanJablo]

Clear and concise description of the problem

The Problem

The raw output in the "Test Results" panel (and the associated terminals) has room for improvement:

1. AI-Assisted Debugging is Hindered: When sharing test failures with AI tools, the fragmented output format creates friction: Expected vs actual values are in separate boxes. The same applies to Stack traces of errors. Because of this, I need to manually copy from 3-4 different places, then reconstruct the context before pasting into an AI chat. This breaks the flow and introduces errors.

2. Manual Reproducibility takes time: currently, there isn't a straightforward way to get a one-click command to replicate the exact test run in a standalone terminal for deeper debugging.

3. Comparing with CLI Behavior Creates Confusion
   Developers are used to running vitest in the terminal and seeing formatted, comprehensive output. When the same test fails in VS Code, the output looks completely different and provides less context. This creates the need to re-run in terminal just to get better output

Example Workflow

Current

Screen.Recording.2026-01-09.at.22.55.28.mov

I exaggerated a bit by copying and pasting... but it's usually not just a simple number to write out.

Suggested

Screen.Recording.2026-01-09.at.23.00.45.mov

Note: Also, note that the exact command to replicate it in the terminal is provided.

Suggested solution

I've opened a pull request here: #707
On which several issues have been pointed out.

I am willing to contribute and find the most idiomatic way to solve this problem, but I would first like to know if the maintainers find value in my proposal.

Alternative

Alternatively, I would like at least one option to:

1. customize the test results output. Or
2. allow the extension to trigger tests in the CLI instead of test-results (similar to how this Jest extension does)

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[sheremet-va]

I would agree with the sentiment, thank you for providing comprehensive description, with videos too.

As for the solution, I think it makes more sense to format the output differently with a custom appendOutput here:

vscode/packages/extension/src/runner.ts

Line 520 in a6cae6e

private markTestCase(

For example, print the error immediately after the test fails with a more compact output to reduce the number of tokens used (maybe similar to the verbose reporter). There is also a similar issue with the error display in #708

I am also fine with printing the command now, but in the future the extension won't use the name pattern.

There was also a nice "copy output" button idea: #676

[GermanJablo]

I'm glad this resonates with you.

I saw #676, but as I understand it, it refers to vitest UI only. #708 is nice, but I think we can do better.

What would be great is if the output were easily customizable. Reporters already exist and seem like a great fit for this purpose. What do you think?

What you mentioned about "a more compact output to reduce the number" could be a new reporter. My proposal focuses more on making the extension's output customizable and having a good default (and using the reporters from the config file seems like a good default to me).

[sheremet-va]

Alright, let's try to use the user reporter. But to make it work with other features like inline logs, we might have to revert the implementation to a custom one instead of using appendOutput: 9abe38b

There also needs to be some change to hooks logic, because right now Vitest triggers onWatcherRerun which is not true, but it helps the extension with keeping the process running.

The logs should also be standardised to just always use the new Writable instead of process.stdout.on

[GermanJablo]

Great! I'll look into this as soon as I can. Thanks!

[RSS1102]

1. I have the same problem. Is it possible to add a quick copy button, at least for a specific error message?

2. Of course, you can also add copy or jump to details for the current file globally (of course, the details will need to be output again)?