Fix ValidatePatternBaseDir for wildcard-in-directory-name patterns

[MichaelSimons]

Summary

ValidatePatternBaseDir in scripts/EvaluateConditionalTestScopes.cs derived the base directory of a glob pattern by taking everything before the first wildcard and trimming a trailing /. When a wildcard appears within a path segment (e.g. test/dotnet-format.*/**), this produced a bogus base directory like test/dotnet-format., which never exists on disk — causing a spurious validation error.

This change trims the prefix back to the last complete / boundary, so the base directory is the nearest real parent segment (test in the example above).

Changes

• scripts/EvaluateConditionalTestScopes.cs: derive the base directory from the last / before the first wildcard instead of the raw prefix.
• test/Microsoft.NET.Infrastructure.Tests/EvaluateConditionalTestScopesTests.cs: add Validation_WildcardInDirectoryName_ValidatesParentSegment covering a test/dotnet-format.*/** pattern where only the parent test directory exists.

Related

This issue was discovered while working on #55399 — this PR is a follow-up fix that came out of that work.

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[azure-pipelines]

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[Copilot]

Pull request overview

Fixes base-directory validation for glob patterns in EvaluateConditionalTestScopes.cs so patterns with wildcards inside a directory name (e.g. test/dotnet-format.*/**) validate against the nearest real parent directory instead of a partial, non-existent path segment.

Changes:

• Update ValidatePatternBaseDir to truncate the prefix at the last / before the first wildcard.
• Add a unit test covering wildcard-in-directory-name patterns to prevent regressions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
scripts/EvaluateConditionalTestScopes.cs	Adjusts glob base-directory derivation to avoid validating partial directory segments when wildcards occur mid-segment.
test/Microsoft.NET.Infrastructure.Tests/EvaluateConditionalTestScopesTests.cs	Adds a regression test ensuring validation succeeds for test/dotnet-format.*/** when only test/ exists.

[MichaelSimons]

/ba-g unrelated intermittent test failure in Microsoft.DotNet.Cli.New.IntegrationTests.DotnetNewSearchTests.CanFilterType