Fix reserved expansion (e.g. "{+var}") when matching resources #1142
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- Add more test cases
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Pull request overview
This pull request fixes URI template parsing for reserved expansion ({+var}), label expansion ({.var}), and path-style parameters ({;var}). The bug was causing templates like samples://{dependency}/{+path} to fail when matching URIs with nested paths.
Changes:
- Fixed reserved expansion to properly match slashes and other reserved characters per RFC 6570
- Fixed label expansion to handle dot-prefixed values with correct separator logic
- Added support for path-style parameter expansion with semicolon-prefixed name=value pairs
- Added 757 lines of comprehensive tests covering all URI template operators and edge cases
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
src/ModelContextProtocol.Core/UriTemplate.cs |
Fixed operator handling in CreateParser switch statement, added AppendPathParameterExpression method, updated separator logic for multi-value expansions, and made UriTemplate class public |
tests/ModelContextProtocol.Tests/UriTemplateCreateParserTests.cs |
Added comprehensive test suite with 757 lines covering all RFC 6570 operators, edge cases, and regression tests for the fixed bugs |
tests/ModelContextProtocol.Tests/Configuration/McpServerResourceRoutingTests.cs |
Added integration test for the reserved expansion bug fix with nested path matching |
halter73
commented
Jan 13, 2026
halter73
changed the title
stephentoub
reviewed
Jan 15, 2026
Comment on lines
209
to
213
| pattern.AppendFormatted("(?:;"); | ||
| pattern.AppendFormatted(paramName); | ||
| pattern.AppendFormatted("(?:=(?<"); | ||
| pattern.AppendFormatted(paramName); | ||
| pattern.AppendFormatted(">[^;/?&]+))?)?"); |
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These can all be AppendLiteral
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Fixed. Should I make the same change to the AppendParameter inside of AppendQueryExpression?
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@heaths