refactor: reduce allocations for context

[vbreuss]

Refactor to speed up string comparison by avoiding allocations for contexts and default comparer and leveraging fast, built-in string APIs.

Key changes:

• Remove list from ResultContexts and replace with custom implementation
• Make comparer parameter nullable across string match types and interface
• Add fast-paths using StringComparison-based APIs when no custom comparer is provided

[Copilot]

Pull Request Overview

Refactor to speed up string comparison by avoiding default comparer allocations and leveraging fast, built-in string APIs. Also enables MSTest v4 test parallelization.

• Make comparer parameter nullable across string match types and interface
• Add fast-paths using StringComparison-based APIs when no custom comparer is provided
• Enable assembly-level test parallelization for MSTest4

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
Tests/Frameworks/aweXpect.Frameworks.MsTest4.Tests/MsTest4FrameworkTests.cs	Adds assembly-level Parallelize attribute to run tests in parallel.
Source/aweXpect.Core/Options/StringEqualityOptions.cs	Stops defaulting comparer and passes through nullable comparer; relies on match types to handle null.
Source/aweXpect.Core/Options/StringEqualityOptions.WildcardMatchType.cs	Allows nullable comparer in signature.
Source/aweXpect.Core/Options/StringEqualityOptions.SuffixMatchType.cs	Adds null-comparer handling with StartsWith/EndsWith fallback using StringComparison.
Source/aweXpect.Core/Options/StringEqualityOptions.RegexMatchType.cs	Allows nullable comparer in signature.
Source/aweXpect.Core/Options/StringEqualityOptions.PrefixMatchType.cs	Adds null-comparer handling with StartsWith fallback using StringComparison.
Source/aweXpect.Core/Options/StringEqualityOptions.ExactMatchType.cs	Adds null-comparer handling with string.Equals fallback using StringComparison.
Source/aweXpect.Core/Options/StringEqualityOptions.ContainingMatchType.cs	Adds null-comparer handling with string.Contains fallback; imports System for StringComparison.
Source/aweXpect.Core/Core/IStringMatchType.cs	Changes interface contract to accept a nullable comparer.

[github-actions]

Test Results

    4 files   -     37      4 suites   - 37   24s ⏱️ - 3m 29s
1 197 tests  - 16 787  1 196 ✅  - 16 786  1 💤  - 1  0 ❌ ±0 
3 483 runs   - 47 109  3 482 ✅  - 47 108  1 💤  - 1  0 ❌ ±0 

Results for commit 19c41fd. ± Comparison against base commit bafccdb.

This pull request removes 16838 and adds 51 tests. Note that renamed tests count towards both.

aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenAwaited_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenAwaited_WithoutReturnValue_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenNotAwaited_ShouldBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenNotAwaited_WithoutReturnValue_ShouldBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenNotAwaited_WithoutReturnValue_WithVerifyInMethod_ShouldStillBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenVerifiedStatically_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenVerifiedStatically_WithoutReturnValue_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenVerifiedWithStaticUsing_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenVerifiedWithStaticUsing_WithoutReturnValue_ShouldNotBeFlagged
aweXpect.Analyzers.Tests.AwaitExpectationAnalyzerTests ‑ WhenVerified_ShouldNotBeFlagged
…

aweXpect.Core.Tests.Core.Exceptions.FailExceptionTests ‑ Message_ShouldBeSet(message: "message0e1de4a0-2065-4a55-b8e4-b7070595a16e")
aweXpect.Core.Tests.Core.Exceptions.FailExceptionTests ‑ Message_ShouldBeSet(message: "message65314c4a-a142-4e3c-aea3-6b50528e2278")
aweXpect.Core.Tests.Core.Exceptions.FailExceptionTests ‑ Message_ShouldBeSet(message: "message6bb08037-901c-4b4f-a094-b281fd2e026c")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "message3135195d-fb30-427a-a020-8e9169c3a6db")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "message48e32c72-4e0e-4ae5-bd71-88c9899d491b")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "messagedacc5425-2833-4d79-818e-8f36e8e3f4fc")
aweXpect.Core.Tests.FailTests ‑ Test_ShouldThrowException(reason: "reason186ad58d-9136-4c26-8765-b1d130554c70")
aweXpect.Core.Tests.FailTests ‑ Test_ShouldThrowException(reason: "reason33619ec5-9ace-415d-904f-4fda1d5d9183")
aweXpect.Core.Tests.FailTests ‑ Test_ShouldThrowException(reason: "reason87bcd92a-f99c-4115-a524-e5d221bcb975")
aweXpect.Core.Tests.FailTests ‑ Unless_ShouldThrowException(condition: False, reason: "reason3642aab1-e546-4921-8df2-d5ed122a1d59")
…

♻️ This comment has been updated with latest results.

[github-actions]

🚀 Benchmark Results

Details

BenchmarkDotNet v0.14.0, Ubuntu 24.04.3 LTS (Noble Numbat)

AMD EPYC 7763, 1 CPU, 4 logical and 2 physical cores

.NET SDK 8.0.415

[Host] : .NET 8.0.21 (8.0.2125.47513), X64 RyuJIT AVX2
Job=InProcess  Toolchain=InProcessEmitToolchain  IterationCount=15

LaunchCount=1  WarmupCount=10

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Bool_aweXpect	265.0 ns	2.08 ns	1.95 ns	0.0424	-	712 B
Bool_FluentAssertions	235.1 ns	1.25 ns	1.11 ns	0.0567	-	952 B
Bool_TUnit	200.3 ns	0.98 ns	0.87 ns	0.0396	-	664 B
Equivalency_aweXpect	294,951.5 ns	868.80 ns	770.17 ns	20.0195	0.9766	335556 B
Equivalency_FluentAssertions	2,179,796.7 ns	14,173.01 ns	11,835.10 ns	273.4375	46.8750	4584416 B
Equivalency_TUnit	294,305.2 ns	1,268.31 ns	1,186.38 ns	13.1836	0.4883	224760 B
Int_GreaterThan_aweXpect	239.1 ns	0.72 ns	0.56 ns	0.0486	-	816 B
Int_GreaterThan_FluentAssertions	241.7 ns	2.06 ns	1.82 ns	0.0730	-	1224 B
Int_GreaterThan_TUnit	218.7 ns	1.36 ns	1.27 ns	0.0486	-	816 B
ItemsCount_AtLeast_aweXpect	499.8 ns	2.77 ns	2.32 ns	0.0868	-	1464 B
ItemsCount_AtLeast_FluentAssertions	469.7 ns	2.48 ns	2.20 ns	0.1197	-	2008 B
ItemsCount_AtLeast_TUnit	14,421.5 ns	81.90 ns	76.61 ns	1.5106	-	25432 B
String_aweXpect	478.2 ns	4.46 ns	4.17 ns	0.0734	-	1232 B
String_FluentAssertions	537.4 ns	9.05 ns	8.03 ns	0.1287	-	2168 B
String_TUnit	254.5 ns	2.97 ns	2.78 ns	0.0496	-	832 B
StringArray_aweXpect	2,008.6 ns	5.98 ns	5.59 ns	0.1717	-	2888 B
StringArray_FluentAssertions	1,232.8 ns	8.32 ns	7.38 ns	0.2480	-	4152 B
StringArray_TUnit	702.4 ns	4.33 ns	4.05 ns	0.0820	-	1376 B
StringArrayInAnyOrder_aweXpect	2,589.4 ns	9.08 ns	8.49 ns	0.1831	-	3080 B
StringArrayInAnyOrder_FluentAssertions	126,330.4 ns	566.47 ns	442.27 ns	3.6621	-	61262 B
StringArrayInAnyOrder_TUnit	789.6 ns	3.72 ns	3.48 ns	0.0858	-	1440 B

[github-actions]

👽 Mutation Results

aweXpect

Details

File	Score	Killed	Survived	Timeout	No Coverage	Ignored	Compile Errors	Total Detected	Total Undetected	Total Mutants

The final mutation score is NaN%

Coverage Thresholds: high:80 low:60 break:0

aweXpect.Core

Details

File	Score	Killed	Survived	Timeout	No Coverage	Ignored	Compile Errors	Total Detected	Total Undetected	Total Mutants
Options/StringEqualityOptions.ContainingMatchType.cs	29.17%	14	3	0	31	13	8	14	34	69
Options/StringEqualityOptions.cs	100.00%	62	0	2	0	13	22	64	0	99
Options/StringEqualityOptions.ExactMatchType.cs	97.44%	73	2	3	0	17	8	76	2	103
Options/StringEqualityOptions.PrefixMatchType.cs	91.94%	57	4	0	1	16	8	57	5	86
Options/StringEqualityOptions.RegexMatchType.cs	89.47%	17	1	0	1	5	8	17	2	32
Options/StringEqualityOptions.SuffixMatchType.cs	63.77%	44	4	0	21	17	8	44	25	94
Options/StringEqualityOptions.WildcardMatchType.cs	100.00%	24	0	0	0	5	8	24	0	37

The final mutation score is 81.32%

Coverage Thresholds: high:80 low:60 break:0

[Copilot]

Pull Request Overview

Copilot reviewed 30 out of 30 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

Source/aweXpect.Core/Core/ResultContexts.cs:66

• The new Add implementation inserts each new node after the head (index 1), changing semantics from append (List.Add) to a modified insertion order. This will reorder contexts compared to previous behavior and may impact message composition. To preserve original append semantics, append to the end of the list: traverse to the tail and set tail._next = context (or maintain a tail pointer for O(1) appends).

	public ResultContexts Add(ResultContext context)
	{
		if (_isOpen)
		{
			if (_first is null)
			{
				_first = context;
			}
			else
			{
				context._next = _first._next;
				_first._next = context;
			}
		}

		return this;
	}

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
42.7% Coverage on New Code
23.2% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

This is addressed in release v2.27.1.