fix: skip non-string MIME metadata in DocumentTypeRouter

[MohammadHijjawi97]

Related Issues

No existing issue. This PR includes a regression test for the crash.

Proposed Changes:

Proposed Changes:

DocumentTypeRouter passed mime_type metadata to re.fullmatch. A list or integer value raised TypeError. Treat non-string MIME metadata as missing and route those documents to unclassified. Also guard invalid file_path values when guessing MIME type.

How did you test it?

Added a unit test for list, integer, and None mime metadata next to a valid string.

Notes for the reviewer

Checklist

• I have read the contributors guidelines and the code of conduct.
• I have updated the related issue with new insights and changes.
• I have added unit tests and updated the docstrings.
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test: and added ! in case the PR includes breaking changes.
• I have documented my code.
• I have added a release note file, following the contributors guidelines.
• I have run pre-commit hooks and fixed any issue.

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[github-actions]

Hi @MohammadHijjawi97, thanks for your interest in contributing to Haystack! 🙏

⚠️ You currently have 5 open pull requests in this repository (#12794, #12792, #12791, #12790 and this one). Our review capacity is limited, so please hold off opening more PRs until we've had a chance to review your first 2 open PRs. This helps us give each contribution the attention it deserves. Thank you!

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[HaystackBot]

Hi @MohammadHijjawi97, thanks a lot for your contribution! 🙏

We noticed that the Contributor License Agreement (CLA) check (license/cla) hasn't passed yet, so we've temporarily moved this PR to draft and paused the review assignment.

To get your PR reviewed, please sign the CLA via the link in the license/cla check below (or in the CLA bot comment). As soon as the check turns green, this PR will automatically be marked ready for review again and a reviewer will be re-assigned.

[HaystackBot]

Thanks for signing the CLA, @MohammadHijjawi97! 🎉 This PR is now ready for review again and the reviewer has been re-assigned.

[MohammadHijjawi97]

CLA is signed now. This is ready for review whenever you have time.

[github-actions]

Coverage report

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
haystack/components/routers
document_type_router.py					144-145
haystack/core/pipeline
pipeline.py
Project Total

This report was generated by python-coverage-comment-action