[duplicate-code] Duplicate Code: CTRF TestResultCapture duplicates constants and Truncate logic from TestResultCaptureHelper

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🔍 Duplicate Code Detected: CTRF TestResultCapture diverges from TestResultCaptureHelper

Analysis of commit cf37d3b

Assignee: @copilot

Summary

src/Platform/Microsoft.Testing.Extensions.CtrfReport/TestResultCapture.cs contains hardcoded constants and a Truncate method that duplicate — and diverge from — SharedExtensionHelpers/TestResultCaptureHelper.cs. The JUnit and HTML report extensions already reference the shared helper; CTRF is the odd one out and has a subtly different (and potentially buggy) Truncate implementation that does not guard against splitting Unicode surrogate pairs.

Duplication Details

Pattern: Hardcoded size constants duplicated from TestResultCaptureHelper

• Severity: Medium
• Occurrences: 5 constants defined independently in CTRF, already centralised in shared helper
• Locations:
  • src/Platform/Microsoft.Testing.Extensions.CtrfReport/TestResultCapture.cs (lines 16–20) — inline values
  • src/Platform/SharedExtensionHelpers/TestResultCaptureHelper.cs (lines 14–18) — canonical source
  • src/Platform/Microsoft.Testing.Extensions.JUnitReport/TestResultCapture.cs (lines 13–17) — already uses helper
  • src/Platform/Microsoft.Testing.Extensions.HtmlReport/TestResultCapture.cs (lines 13–17) — already uses helper

CTRF (duplicated inline values):

internal const int MaxStandardStreamLength = 32 * 1024;
internal const int MaxStackTraceLength     = 32 * 1024;
internal const int MaxMessageLength        = 16 * 1024;
internal const int MaxIdentityFieldLength  =  4 * 1024;
internal const int MaxTraitFieldLength     =       1024;

JUnit / HTML (correct — delegate to shared helper):

internal const int MaxStandardStreamLength = TestResultCaptureHelper.MaxStandardStreamLength;
internal const int MaxStackTraceLength     = TestResultCaptureHelper.MaxStackTraceLength;
// ...

Pattern: Truncate method implementation duplicated — and divergent

• Severity: High (functional divergence — potential bug)
• Occurrences: Local CTRF copy vs shared helper
• Locations:
  • src/Platform/Microsoft.Testing.Extensions.CtrfReport/TestResultCapture.cs (lines 151–156) — own implementation
  • src/Platform/SharedExtensionHelpers/TestResultCaptureHelper.cs (lines 46–62) — canonical with surrogate-pair guard

CTRF Truncate (missing surrogate-pair guard):

internal static string? Truncate(string? value, int maxLength)
    => value is null || value.Length <= maxLength
        ? value
        : value.Substring(0, maxLength)
            + $"\n...[truncated, original length: {value.Length.ToString(CultureInfo.InvariantCulture)}]";

TestResultCaptureHelper.Truncate (correct — handles surrogate pairs):

int cut = maxLength;
if (cut > 0 && cut < value.Length && char.IsHighSurrogate(value[cut - 1]))
    cut--;   // drop the high surrogate to avoid an invalid UTF-16 string
return value.Substring(0, cut) + $"\n...[truncated, original length: ...]";

Impact Analysis

• Maintainability: If the shared constants or Truncate logic in TestResultCaptureHelper are updated, the CTRF copy will silently drift further. The JUnit/HTML variants already delegate to the helper, making CTRF the outlier.
• Bug Risk: Test-node display names or UIDs that end on a Unicode surrogate pair will produce an invalid string in the CTRF report (FormatException / JsonException when serialising) while working correctly in HTML and JUnit reports.
• Code Bloat: ~12 lines of redundant code in a file that could be removed immediately.

Refactoring Recommendations

1. Replace inline constants with TestResultCaptureHelper.* references

   • In src/Platform/Microsoft.Testing.Extensions.CtrfReport/TestResultCapture.cs, replace lines 16–20 with:

     internal const int MaxStandardStreamLength = TestResultCaptureHelper.MaxStandardStreamLength;
     internal const int MaxStackTraceLength     = TestResultCaptureHelper.MaxStackTraceLength;
     internal const int MaxMessageLength        = TestResultCaptureHelper.MaxMessageLength;
     internal const int MaxIdentityFieldLength  = TestResultCaptureHelper.MaxIdentityFieldLength;
     internal const int MaxTraitFieldLength     = TestResultCaptureHelper.MaxTraitFieldLength;

   • Estimated effort: < 15 minutes
   • Benefits: single source of truth; future constant changes propagate automatically

2. Replace local Truncate with delegation to shared helper

   • Replace the CTRF Truncate implementation body with => TestResultCaptureHelper.Truncate(value, maxLength); — identical to the HTML pattern
   • Estimated effort: < 5 minutes
   • Benefits: fixes the surrogate-pair bug; keeps all reports consistent

Implementation Checklist

• Review duplication findings
• Replace the 5 inline constants in CTRF TestResultCapture with TestResultCaptureHelper.* references
• Replace the CTRF Truncate body with delegation to TestResultCaptureHelper.Truncate
• Remove the extra using directives in CtrfReport/TestResultCapture.cs that are no longer needed after delegation (e.g., Microsoft.Testing.Platform.Helpers, Microsoft.Testing.Platform)
• Verify CTRF report unit tests still pass
• Verify no functionality broken

Analysis Metadata

• Analyzed Files: 4 (CtrfReport/TestResultCapture.cs, JUnitReport/TestResultCapture.cs, HtmlReport/TestResultCapture.cs, SharedExtensionHelpers/TestResultCaptureHelper.cs)
• Detection Method: Semantic code analysis + diff between peer files
• Commit: cf37d3b
• Analysis Date: 2026-06-15

🤖 Automated content by GitHub Copilot. Posted via a maintainer's GitHub token, so it appears under their account — the account owner did not write or approve this content personally. Generated by the Duplicate Code Detector workflow. · 979.9 AIC · ⌖ 14.3 AIC · [◷]( · ◷)

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