feat: improve visualization of string difference for suffix

[vbreuss]

This PR improves string difference visualization for suffix matching by adding proper context for prefix/suffix comparisons and enhancing string difference handling. The change makes error messages more specific about whether differences are being checked as prefixes or suffixes.

Key changes:

• Adds new MatchType.Prefix and MatchType.Suffix enum values to distinguish different comparison modes
• Implements suffix-specific string difference calculation that compares from the end of strings
• Updates test expectations to show clearer error messages with "expected prefix" and "expected suffix" label

---

• Fixes Use string diff visualization also for StartsWith and EndsWith #702

[Copilot]

Pull Request Overview

This PR improves string difference visualization for suffix matching by adding proper context for prefix/suffix comparisons and enhancing string difference handling. The change addresses issue #702 by making error messages more specific about whether differences are being checked as prefixes or suffixes.

• Adds new MatchType.Prefix and MatchType.Suffix enum values to distinguish different comparison modes
• Implements suffix-specific string difference calculation that compares from the end of strings
• Updates test expectations to show clearer error messages with "expected prefix" and "expected suffix" labels

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
StringDifference.cs	Core implementation adding suffix match type, index calculation from end, and improved visualization
StringEqualityOptions.SuffixMatchType.cs	Updated to use new suffix match type for more accurate error reporting
StringEqualityOptions.PrefixMatchType.cs	Updated to use new prefix match type for consistent handling
ThatString.StartsWith.cs	Removed inline constraint class (likely moved to shared location)
ThatString.EndsWith.cs	Removed inline constraint class (likely moved to shared location)
API test files	Updated to include new enum values in public API
Test files	Updated expected error messages to show "expected prefix" and "expected suffix" labels

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
81.6% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Test Results

    4 files   -     34      4 suites   - 34   17s ⏱️ - 4m 13s
1 156 tests  - 16 440  1 155 ✅  - 16 439  1 💤  - 1  0 ❌ ±0 
3 360 runs   - 46 092  3 359 ✅  - 46 091  1 💤  - 1  0 ❌ ±0 

Results for commit 5ba2f4b. ± Comparison against base commit 4dc12c1.

This pull request removes 16533 and adds 93 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: "message8dcb70dd-51a8-482a-b151-f455aa48774b")
aweXpect.Core.Tests.Core.Exceptions.FailExceptionTests ‑ Message_ShouldBeSet(message: "message95c37750-7a9b-48cd-9eee-fdec2de21c52")
aweXpect.Core.Tests.Core.Exceptions.FailExceptionTests ‑ Message_ShouldBeSet(message: "messageef5eb360-4930-4107-8b37-1bb43f23352c")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "message30155fb0-7a80-4cbb-8440-922ee0472d74")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "message71f30f2f-9510-4f30-982b-6176d9bc676a")
aweXpect.Core.Tests.Core.Exceptions.SkipExceptionTests ‑ Message_ShouldBeSet(message: "message7b4627c3-6286-4485-95d0-8775e67bf473")
aweXpect.Core.Tests.Core.StringDifferenceTests ‑ ShouldCacheIndexOfFirstMismatch(matchType: Equality, expectedIndex: -1)
aweXpect.Core.Tests.Core.StringDifferenceTests ‑ ShouldCacheIndexOfFirstMismatch(matchType: Prefix, expectedIndex: -1)
aweXpect.Core.Tests.Core.StringDifferenceTests ‑ ShouldCacheIndexOfFirstMismatch(matchType: Regex, expectedIndex: 0)
aweXpect.Core.Tests.Core.StringDifferenceTests ‑ ShouldCacheIndexOfFirstMismatch(matchType: Suffix, expectedIndex: -1)
…

[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 8.0.413

[Host] : .NET 8.0.19 (8.0.1925.36514), X64 RyuJIT AVX2
Job=InProcess  Toolchain=InProcessEmitToolchain  IterationCount=15

LaunchCount=1  WarmupCount=10

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Bool_aweXpect	222.2 ns	2.80 ns	2.49 ns	0.0300	-	504 B
Bool_FluentAssertions	240.5 ns	1.52 ns	1.35 ns	0.0567	-	952 B
Bool_TUnit	889.0 ns	5.64 ns	5.28 ns	0.1431	-	2408 B
Equivalency_aweXpect	305,791.9 ns	1,999.60 ns	1,870.43 ns	20.0195	0.9766	335556 B
Equivalency_FluentAssertions	2,259,553.8 ns	21,868.50 ns	20,455.81 ns	273.4375	46.8750	4584416 B
Equivalency_TUnit	708,133.1 ns	6,098.54 ns	5,704.58 ns	51.7578	2.9297	880545 B
Int_GreaterThan_aweXpect	243.4 ns	1.59 ns	1.49 ns	0.0486	-	816 B
Int_GreaterThan_FluentAssertions	251.4 ns	1.69 ns	1.58 ns	0.0730	-	1224 B
Int_GreaterThan_TUnit	1,173.8 ns	8.93 ns	7.92 ns	0.1774	-	2984 B
ItemsCount_AtLeast_aweXpect	473.7 ns	1.97 ns	1.84 ns	0.0873	-	1464 B
ItemsCount_AtLeast_FluentAssertions	468.1 ns	3.04 ns	2.54 ns	0.1197	-	2008 B
ItemsCount_AtLeast_TUnit	14,880.3 ns	140.59 ns	131.51 ns	1.6327	-	27480 B
String_aweXpect	421.9 ns	2.17 ns	1.92 ns	0.0734	-	1232 B
String_FluentAssertions	456.9 ns	2.10 ns	1.76 ns	0.1292	-	2168 B
String_TUnit	1,184.2 ns	5.04 ns	4.47 ns	0.1831	-	3072 B
StringArray_aweXpect	1,746.8 ns	4.52 ns	4.23 ns	0.1717	-	2888 B
StringArray_FluentAssertions	1,319.7 ns	24.79 ns	21.98 ns	0.2480	-	4152 B
StringArray_TUnit	3,215.6 ns	8.77 ns	8.20 ns	0.3128	-	5296 B
StringArrayInAnyOrder_aweXpect	2,274.2 ns	7.72 ns	7.22 ns	0.1831	-	3080 B
StringArrayInAnyOrder_FluentAssertions	150,260.1 ns	1,500.36 ns	1,403.44 ns	3.4180	-	63787 B
StringArrayInAnyOrder_TUnit	3,816.6 ns	12.16 ns	10.78 ns	0.3815	-	6488 B

[github-actions]

This is addressed in release v2.23.0.