feat(srv): Add HTTP 301 redirects for common URL mistakes

[Copilot]

Implementation Plan for URL Redirects

• Explore existing route handlers and understand Actix-Web routing patterns
• Create redirect handlers co-located with their targets
  • Add pluralization redirect handlers (styles→style, sprites→sprite, etc.)
  • Add tile format suffix redirect handlers (.pbf, .mvt, .mlt)
  • Preserve query strings in all redirects
  • Use HTTP 301 (Permanent Redirect)
  • Use proper visibility (pub(crate))
• Update route registration in martin/src/srv/server.rs
  • Tile suffix redirects before main tile route (for correct precedence)
  • Pluralization redirects after main routes (as fallbacks)
• Build and test the implementation
  • Run cargo build to verify compilation
  • Test redirect handlers manually with curl (completed earlier)
  • Verify query string preservation (completed earlier)
  • Fix clippy warnings
• Manual testing completed successfully
  • Verified all pluralization redirects work
  • Verified all tile format suffix redirects work
  • Verified /tiles/ prefix redirect works
  • Verified query string preservation
• Code refactoring per new requirement
  • Moved redirects to be co-located with their target handlers
  • Removed separate redirects.rs module
  • Simpler, more maintainable code organization
• Address code review feedback
  • Changed redirect handler visibility to pub(crate)
  • Created DebouncedWarning helper to eliminate code duplication
  • Updated warning message format per feedback
  • Refactored DebouncedWarning to use closure API for proper tracing integration
• Add integration tests
  • Created test_redirect function in test.sh
  • Added tests for all pluralization redirects
  • Added tests for tile format suffix redirects
  • Added tests for query string preservation (tiles only)
  • Fixed test function to not create litter files
• Final validation and completion

Original prompt

Problem

Currently, when users make common pluralization mistakes (like /styles/ instead of /style/) or add explicit file extensions to tile endpoints (like .pbf, .mvt, .mlt), they receive a 404 error. These should instead return a permanent redirect (HTTP 301) to the correct canonical URL.

Examples of URLs that should redirect:

Pluralization redirects:

• /styles/{style_id} → /style/{style_id} (301)
• /sprites/{source_ids}.json → /sprite/{source_ids}.json (301)
• /sprites/{source_ids}.png → /sprite/{source_ids}.png (301)
• /sdf_sprites/{source_ids}.json → /sdf_sprite/{source_ids}.json (301)
• /sdf_sprites/{source_ids}.png → /sdf_sprite/{source_ids}.png (301)
• /fonts/{fontstack}/{start}-{end} → /font/{fontstack}/{start}-{end} (301)
• /tiles/{source_ids}/{z}/{x}/{y} → /{source_ids}/{z}/{x}/{y} (301)

Tile format suffix redirects:

For tile endpoints like /{source_ids}/{z}/{x}/{y}, also support:

• /{source_ids}/{z}/{x}/{y}.pbf → /{source_ids}/{z}/{x}/{y} (301)
• /{source_ids}/{z}/{x}/{y}.mvt → /{source_ids}/{z}/{x}/{y} (301)
• /{source_ids}/{z}/{x}/{y}.mlt → /{source_ids}/{z}/{x}/{y} (301)

Implementation Requirements

1. Create a new module martin/src/srv/redirects.rs that handles:

   • Middleware or route handlers for common pluralization mistakes
   • Handlers for tile format suffix redirects
   • All redirects must use HTTP 301 (Permanent Redirect)
   • Preserve query strings when redirecting

2. Register redirect routes in martin/src/srv/server.rs:

   • Add redirect handlers to the router
   • Ensure they are registered after the main routes so they act as fallbacks
   • Use Actix-Web's route macro system similar to existing handlers

3. Pattern matching approach:

   • For pluralization: Use route patterns that match the plural form and redirect to singular
   • For tile suffixes: Use route patterns like /{source_ids}/{z}/{x}/{y}.{ext:pbf|mvt|mlt} that strip the extension
   • Preserve all path parameters and query strings in the redirect

4. Code quality requirements:

   • Follow the existing code style in martin/src/srv/ modules
   • Use proper error types (ActixResult)
   • Add appropriate comments explaining the redirect logic
   • Ensure proper imports and module structure

5. Testing considerations:

   • The implementation should work with existing integration tests
   • Redirects should preserve the full path including source_ids, coordinates, etc.
   • Query parameters should be preserved across redirects

Key Files to Modify

1. Create: martin/src/srv/redirects.rs - New module for redirect handlers
2. Modify: martin/src/srv/server.rs - Add redirect route registration
3. Modify: martin/src/srv/mod.rs - Add module declaration if needed

Expected Behavior

Before:

$ curl -I http://localhost:3000/styles/my_style
HTTP/1.1 404 Not Found

After:

$ curl -I http://localhost:3000/styles/my_style
HTTP/1.1 301 Moved Permanently
Location: /style/my_style

Before:

$ curl -I http://localhost:3000/points/0/0/0.pbf
HTTP/1.1 404 Not Found

After:

$ curl -I http://localhost:3000/points/0/0/0.pbf
HTTP/1.1 301 Moved Permanently
Location: /points/0/0/0

Notes

• This is a backend-only change (Rust scope)
• Follows Martin's engineering principles of user experience and correctness
• Improves developer experience by being forgiving of common mistakes
• Uses HTTP standards properly (301 for permanent redirects)

This pull request was created from Copilot chat.

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[Copilot]

@copilot the API should be DEBOUNCED_FN.once_per_hour(|| warn!(...
The reason is that this way tracings log filtering works as expected.

Fixed in commit 58513e8 - refactored DebouncedWarning API to accept a closure. The new API is WARNING.once_per_hour(|| warn!(...)) which keeps the warn! call site in the caller's context, ensuring tracing's log filtering works correctly.