Unhelpful startup error when nothing is passed to `--reporter` flag

[Bharath314]

Describe the bug

Running Vitest with --reporter but without a reporter name

vitest --reporter

results in an internal-looking error:

Error: Failed to load custom Reporter from true
...
[cause]: Error: Failed to convert JavaScript value `Boolean true` into rust type `String`
...

An error message like this would be more helpful:

Error: The --reporter option requires a reporter name.
Available examples: verbose, dot, json

Reproduction

https://stackblitz.com/edit/vitest-dev-vitest-nvlgtsbv?file=README.md&file=md!README.md&initialPath=__vitest__/

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 22.22.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    @vitest/ui: latest => 4.1.11 
    vite: latest => 8.2.1 
    vitest: latest => 4.1.11

Used Package Manager

npm

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[Bharath314]

Can I work on this issue if it's triaged and simple enough for a first-timer to fix?

[AriPerkkio]

I think this happens with many CLI options. Do we document using --reporter without options somewhere? Sounds like documentation issue rather than a runtime fix one. 🤔

[Bharath314]

Do we document using --reporter without options somewhere?

I haven't come across any documentation that uses --reporter without options.

Sounds like documentation issue rather than a runtime fix one.

I do think that it is a runtime error because, from my understanding, when nothing is passed to --reporter, true is implicitly passed and that causes the error "[cause]: Error: Failed to convert JavaScript value Boolean true into rust type String".

Not really a pressing issue, but it is a nice UX improvement to have a helpful error message that tells the users what they did wrong.

[Bharath314]

The issue is bigger than I thought. Invalid options aren't handled properly. For example, a typo like npx vitest --reporter=verbos results in a wordy error that doesn't tell the user what they did wrong. I can help identify the flags that don't gracefully handle invalid options and add handling for them.