xUnit Migration: Assert.All converted to non-existent AllSatisfy method

[thomhurst]

Description

When using the TUnit xUnit migration code fixer (TUXU0001), the fixer converts xUnit's Assert.All() to .AllSatisfy(), but this method doesn't exist on TUnit's collection assertions, resulting in CS1061 compilation errors.

Steps to Reproduce

1. Create an xUnit test using Assert.All():

using Xunit;

[Fact]
public void Test_All_Items()
{
    var items = new[] { 1, 2, 3 };
    Assert.All(items, item => Assert.True(item > 0));
}

2. Install TUnit package and run dotnet format analyzers --severity info --diagnostics TUXU0001

Expected Behavior

The code should be converted to valid TUnit syntax. If .AllSatisfy() doesn't exist, either:

1. The method should be added to TUnit, or
2. The fixer should convert to an existing TUnit pattern

Actual Behavior

The code is converted to:

[Test]
public async Task Test_All_Items()
{
    var items = new[] { 1, 2, 3 };
    await Assert.That(items).AllSatisfy(item => Assert.True(item > 0));
}

This causes:

error CS1061: 'CollectionAssertion<int>' does not contain a definition for 'AllSatisfy' and no accessible extension method 'AllSatisfy' accepting a first argument of type 'CollectionAssertion<int>' could be found

Affected Assertion Types

The issue affects multiple collection assertion types:

• CollectionAssertion<T>
• ReadOnlyListAssertion<T>

Impact

This affects tests that validate all items in a collection satisfy a condition. In the Moq test suite, this resulted in 28+ compilation errors.

Environment

• TUnit Version: 1.9.91
• .NET SDK: 10.0.101
• OS: Windows

[claude]

Analysis Summary

Issue Type: Bug in xUnit migration code fixer (TUXU0001)
Priority: High - Blocks xUnit migration with compilation errors

This issue is part of a series of xUnit migration problems discovered during the Moq test suite migration. Related issues:

• xUnit Migration: Code fixer does not add 'using System.Threading.Tasks;' directive #4330 - Missing using directives
• xUnit Migration: Assert.Throws converted to undefined 'awaitAssert.ThrowsAsync' #4331 - Assert.Throws conversion issues
• xUnit Migration: Record.Exception() pattern not converted #4332 - Record.Exception() not converted
• xUnit Migration: Assert.Same converted to non-existent IsSameReference method #4333 - Assert.Same → IsSameReference (non-existent)
• xUnit Migration: Exception property access (.Message, .ParamName) not properly converted #4334 - Exception property access conversion
• xUnit Migration: Summary of code fixer issues found during Moq migration #4336 - Summary of all migration issues

Root Cause: The code fixer converts Assert.All() to .AllSatisfy() but this method doesn't exist on TUnit's collection assertions.

Suggested Fix: Either:

1. Add AllSatisfy() method to CollectionAssertion<T> and ReadOnlyListAssertion<T>, OR
2. Update the fixer to use an existing TUnit pattern (e.g., iterate and assert, or use a different assertion method)