Improve redirects documentation with advanced regex patterns

[devin-ai-integration]

Improve redirects documentation with advanced regex patterns

Summary

Enhanced the redirects documentation based on user feedback about difficulty configuring complex regex-based redirects. The user specifically mentioned:

• Needing Claude's help to configure regex redirects
• Lacking detail about named capture groups
• Path-to-RegExp docs being insufficient for their use case

Changes made to fern/snippets/redirects.mdx:

• Added "Advanced patterns" section with named capture group examples
• Documented the {0} literal delimiter syntax for separating parameters
• Included real-world examples (release notes migration, versioned APIs)
• Added pattern syntax reference table
• Updated link text from "regex" to "Path-to-RegExp" for clarity

Review & Testing Checklist for Human

• Verify redirect syntax is correct - Test the advanced pattern examples in an actual docs.yml to ensure they work (especially the {0} delimiter and double backslashes)
• Check regex escaping - Confirm that \\d{4} and similar patterns are properly escaped for YAML
• Test named capture group reuse - Verify that captured parameters (:year, :month, etc.) can actually be referenced in destination URLs as shown
• Review against Path-to-RegExp docs - Cross-check that our examples align with Path-to-RegExp actual behavior

Recommended test plan:

1. Create a test docs.yml with the new advanced redirect examples
2. Deploy to a preview environment
3. Test that URLs like /release-notes/2024-12 redirect correctly to /docs/release-notes/2024/12/1

Notes

• These improvements address direct user feedback from a customer who struggled with complex redirect configuration
• The examples are based on their actual use case (migrating old release notes URLs)
• I could not test these locally, so manual verification is important

Session: https://app.devin.ai/sessions/3ac1263b00304808bdeffdb336395807
Requested by: danny@buildwithfern.com (@dannysheridan)

[devin-ai-integration]

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