LINQ: Fixes array.Contains() for .NET 10 MemoryExtensions#5585
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kirankumarkolli wants to merge 6 commits intomasterfrom
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LINQ: Fixes array.Contains() for .NET 10 MemoryExtensions#5585kirankumarkolli wants to merge 6 commits intomasterfrom
kirankumarkolli wants to merge 6 commits intomasterfrom
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In .NET 10, array.Contains() may resolve to MemoryExtensions.Contains(ReadOnlySpan<T>, T) instead of Enumerable.Contains. Since ReadOnlySpan doesn't implement IEnumerable, the existing IsEnumerable() check fails. Changes: - Add IsMemoryExtensionsMethod() helper to detect MemoryExtensions methods - Route MemoryExtensions.Contains to ArrayBuiltinFunctions for proper SQL translation - Add unit tests for MemoryExtensions detection Fixes #5518
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kirankumarkolli
changed the title
- TestMemoryExtensionsContainsExpressionDetection: Verifies MemoryExtensions.Contains<T>(ReadOnlySpan<T>, T) is properly detected - TestBuiltinFunctionVisitorMemoryExtensionsCheck: Simulates .NET 10 expression and validates our fix - TestEnumerableContainsNotDetectedAsMemoryExtensions: Ensures Enumerable.Contains is unaffected These tests programmatically create the expression trees that .NET 10 generates for array.Contains(), verifying the fix handles them correctly.
kirankumarkolli
commented
Feb 2, 2026
kirankumarkolli
requested review from
FabianMeiswinkel,
adityasa,
khdang,
kirillg,
neildsh and
sboshra
as code owners
…uction Addresses review comment: replaced superficial type-name checks with a test that constructs an actual MemoryExtensions.Contains MethodCallExpression and verifies the DeclaringType matches. Removed redundant tests, kept array IsEnumerable and Enumerable negative check. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Contributor
|
@kirankumarkolli Minh had a pr open to address this: He ran into some issues, since for testing it needed projects to be upgraded to .NET 9 - partly why it's not merged. |
Contributor
|
Hi @kirankumarkolli — this PR has been idle for ~36 days. What's the current ETA / status? Flagging as part of an open-PR cleanup pass; if it's no longer being pursued we can close it. No auto-close — just looking for a status update. |
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Azure Pipelines: Successfully started running 1 pipeline(s). |
kirankumarkolli
requested review from
jeet1995,
kundadebdatta and
xinlian12
as code owners
|
Azure Pipelines: Successfully started running 1 pipeline(s). |
Contributor
|
Closed in favor of #5819 |
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Description
🤖 This PR was authored by GitHub Copilot as part of an automated issue triage and resolution workflow.
Fixes #5518
In .NET 10,
array.Contains(x)may resolve toMemoryExtensions.Contains(ReadOnlySpan<T>, T)instead ofEnumerable.Contains. SinceReadOnlySpan<T>doesn't implementIEnumerable, the existing check inBuiltinFunctionVisitorfails withNotSupportedException.Issue Summary
Root Cause Analysis
Code Path
Root Cause
In .NET 10, the C# compiler resolves
array.Contains(item)toMemoryExtensions.Contains<T>(ReadOnlySpan<T>, T)instead ofEnumerable.Contains<T>(IEnumerable<T>, T).The LINQ translator checks
declaringType.IsEnumerable()to route extension methods, butReadOnlySpan<T>(the first parameter type ofMemoryExtensions.Contains) doesn't implementIEnumerable<T>, causing the method to be unrecognized.This is a forward compatibility issue - existing code works in .NET 8/9 but fails in .NET 10+ previews.
Changes Made
Files Modified
BuiltinFunctionVisitor.csIsMemoryExtensionsMethod()helper and routing logicLinqMemoryExtensionsTests.csCode Changes
IsMemoryExtensionsMethod()helper - Detects when method is fromSystem.MemoryExtensionsby checkingDeclaringType.FullNameArrayBuiltinFunctionswhich already handles both 1-arg and 2-arg Contains signaturesGenerated Output (Before/After)
Before (incorrect):
After (correct):
Testing
Local Test Results
Breaking Changes
None - This is an additive fix that enables previously unsupported scenarios.
Checklist
Generated by GitHub Copilot CLI Agent