This analyzer is really getting unnecessarily too complicated and handling too much stuff 😕

We can split to have 1 rule per target refactoring but I am not so sure this is helping much (user pov or even for our maintenance). Do you have some other ideas?

Do you have some other ideas?

Nothing immediately in mind. I'll try to look deeper in the current implementation later. Fine for me for now to make the fix here.

@copilot there are some issues:

azure-pipelines
/ microsoft.testfx (Build Linux Debug)
test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2.cs#L78

test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2.cs(78,1): error : [WhenAssertIsTrueWithLinqContainsAndComparer] [net8.0] Test method MSTest.Analyzers.Test.UseProperAssertMethodsAnalyzerTests.WhenAssertIsTrueWithLinqContainsAndComparer threw exception:
System.InvalidOperationException: Context: Diagnostics of test state
Expected diagnostic to start on line "13" was actually on line "12"

Expected diagnostic:
// /0/Test0.cs(13,9,13,53): info MSTEST0037: Use 'Assert.Contains' instead of 'Assert.IsTrue'
VerifyCS.Diagnostic().WithSpan(13, 9, 13, 53).WithArguments("Contains", "IsTrue"),

Actual diagnostic:
// /0/Test0.cs(12,24): error CS0103: The name 'StringComparer' does not exist in the current context
DiagnosticResult.CompilerError("CS0103").WithSpan(12, 24, 12, 38).WithArguments("StringComparer"),

@copilot there are some issues:

azure-pipelines
...

Fixed in 0d0776f — the test code snippets for WhenAssertIsTrueWithLinqContainsAndComparer and WhenAssertIsFalseWithLinqContainsAndComparer were missing using System;, which is needed for StringComparer. Added the missing import to both test code and fixed code strings.

@copilot please ensure everything builds and all tests are passing. THis test is failing:

test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2.cs#L78

test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2.cs(78,1): error : [WhenAssertIsFalseWithLinqContainsAndComparer] [net8.0] Test method MSTest.Analyzers.Test.UseProperAssertMethodsAnalyzerTests.WhenAssertIsFalseWithLinqContainsAndComparer threw exception:
System.InvalidOperationException: Context: Iterative code fix application
content of '/0/Test0.cs' did not match. Diff shown with expected as baseline:
using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Collections.Generic;
using System.Linq;

[TestClass]
public class MyTestClass
{
[TestMethod]
public void MyTestMethod()
{
IEnumerable items = new List { "a", "b", "c" };
var comparer = StringComparer.OrdinalIgnoreCase;

•    Assert.DoesNotContain("X", items, comparer);
  

•    Assert.IsFalse(items.Contains("X", comparer));
  

  }
  }

@copilot please ensure everything builds and all tests are passing. THis test is failing:

test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2.cs#L78
...

Fixed in 49076b6. The root cause was that root.FindNode() returns ArgumentSyntax (outermost for tied spans) when locating the sub-expressions ("X" and comparer) within the inner items.Contains("X", comparer) call. The fixer was only checking for ExpressionSyntax, so it bailed out without applying the fix. Added a TryGetExpressionFromNode helper that extracts the expression from either ArgumentSyntax or ExpressionSyntax, consistent with how the existing FixAssertMethodForAddArgumentModeAsync handles this pattern.