Use range indexer in SubstringAfterLast

[Copilot]

• Replace str.Substring(index + sub.Length, str.Length - index - sub.Length) with str[(index + sub.Length)..] in SubstringAfterLast
• Fix formatting: use single-line ternary consistent with SubstringUntil and SubstringUntilLast

Original prompt

Problem

In GitHubActionsTestLogger/Utils/Extensions/StringExtensions.cs, the SubstringAfterLast method uses the old string.Substring(startIndex, length) overload, which requires manually computing the length:

public string SubstringAfterLast(
    string sub,
    StringComparison comparison = StringComparison.Ordinal
)
{
    var index = str.LastIndexOf(sub, comparison);
    return index >= 0
        ? str.Substring(index + sub.Length, str.Length - index - sub.Length)
        : "";
}

This can be simplified to use the range indexer str[(index + sub.Length)..], consistent with how SubstringUntil and SubstringUntilLast are already written in the same file (str[..index]).

Fix

Replace the Substring(startIndex, length) call with a range slice:

public string SubstringAfterLast(
    string sub,
    StringComparison comparison = StringComparison.Ordinal
)
{
    var index = str.LastIndexOf(sub, comparison);
    return index >= 0
        ? str[(index + sub.Length)..]
        : "";
}

No functional behavior changes.

This pull request was created from Copilot chat.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.46%. Comparing base (1d89cf4) to head (05fec3c).

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #62   +/-   ##
=======================================
  Coverage   84.46%   84.46%           
=======================================
  Files          23       23           
  Lines         721      721           
  Branches       85       85           
=======================================
  Hits          609      609           
  Misses         58       58           
  Partials       54       54           

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[Copilot]

Pull request overview

This pull request refactors the SubstringAfterLast method in StringExtensions.cs to use modern C# range indexer syntax for improved code consistency and readability. The change replaces verbose Substring(startIndex, length) arithmetic with the cleaner range indexer syntax str[(index + sub.Length)..], aligning with the existing implementation patterns of SubstringUntil and SubstringUntilLast in the same file.

Changes:

• Simplified string slicing in SubstringAfterLast by replacing Substring method call with range indexer syntax

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[Tyrrrz]

@copilot fix formatting

[Copilot]

@copilot fix formatting

Fixed in db08693 — collapsed the multi-line ternary to a single line and flipped the condition to index < 0, matching the style of SubstringUntil and SubstringUntilLast.