Avoid TestContext write string allocations#10105
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Evangelink merged 2 commits intoJul 21, 2026
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Skip null-character replacement when the input contains no null characters. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: abd02d85-66b7-43e1-b3ac-b08419abb848
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Pull request overview
Optimizes null-character escaping in TestContext.Write and WriteLine.
Changes:
- Centralizes escaping in
EscapeNullChars. - Adds a pre-check before replacement.
Show a summary per file
| File | Description |
|---|---|
TestContextImplementation.cs |
Updates four write paths to use the helper. |
Review details
- Files reviewed: 1/1 changed files
- Comments generated: 1
- Review effort level: Medium
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Review Summary
Verdict: Looks good ✅
This is a clean, focused performance optimization. The new EscapeNullChars helper avoids the Replace allocation when no null characters are present (the common case). The [return: NotNullIfNotNull] annotation preserves nullability flow.
All 22 dimensions checked — no issues found. The change is minimal, correct, and well-structured.
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Evangelink
enabled auto-merge (squash)
July 21, 2026 10:56
This reverts commit b8a83fd.
0101
approved these changes
Jul 21, 2026
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Summary
Avoid calling
string.ReplaceinTestContext.WriteandWriteLinewhen the input contains no null characters. The new helper returns the original string in the common case and preserves the existing escaping behavior when null characters are present.Fixes #10095
Testing
MSTestAdapter.PlatformServices.UnitTestsfornet8.0MSTestAdapter.PlatformServices.UnitTeststests