Add proper handling when a property’s backing field cannot be inferred or the unsafe accessor cannot be generated.

[kawasaniac]

My take on adding additional handling for the following issue: #35219

Throws InvalidOperationException with proper message as in DesignStrings (CompiledModelBackingFieldNotFound and CompiledModelUnsafeAccessorNull). Plus added additional exceptions specifically for this case.

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        Fixes #bugnumber

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[kawasaniac]

@dotnet-policy-service agree

[AndriySvyryd]

Add tests for these cases to https://github.com/dotnet/efcore/blob/release/10.0/test/EFCore.Specification.Tests/Scaffolding/CompiledModelTestBase.cs

[AndriySvyryd]

Thanks for your contribution

[Copilot]

Pull request overview

This PR improves design-time compiled model generation (especially for --nativeaot) by replacing a NullReferenceException failure mode with a targeted InvalidOperationException and a new DesignStrings message when EF can’t determine the backing member to use.

Changes:

• Add a new design-time resource string CompiledModelBackingFieldNotFound and expose it via DesignStrings.
• Update CSharpRuntimeModelCodeGenerator to throw a clearer InvalidOperationException instead of flowing a null MemberInfo into unsafe-accessor name generation.
• Add a new compiled-model scaffolding test covering the backing-field-not-found scenario.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

File	Description
test/EFCore.Specification.Tests/Scaffolding/CompiledModelTestBase.cs	Adds a NativeAOT test case expecting the new error message and a new entity type used by that test.
src/EFCore.Design/Scaffolding/Internal/CSharpRuntimeModelCodeGenerator.cs	Adds a guard/exception when GetMemberInfo(...) yields null during unsafe-accessor registration.
src/EFCore.Design/Properties/DesignStrings.resx	Adds CompiledModelBackingFieldNotFound string (and reorders/moves some existing entries).
src/EFCore.Design/Properties/DesignStrings.Designer.cs	Adds the strongly-typed accessor for CompiledModelBackingFieldNotFound (and reflects resource reordering).

Files not reviewed (1)

• src/EFCore.Design/Properties/DesignStrings.Designer.cs: Language not supported

[Copilot]

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

Files not reviewed (1)

• src/EFCore.Design/Properties/DesignStrings.Designer.cs: Language not supported