Fix S6605 and S6617 FP: Should not be applied to expressions used by EntityFramework

[KuraiAndras]

Description

The S6605 analyzer flags code inside expressions which will cause EF queries to be uncompilable.

I understand that checking for usage specifically related to EF might be problematic from the analyzer's side, but it is a very common use case and manually suppressing the issue is problematic. The analyzer itself is very useful in all other settings so turning it off by default is not the best solution.

Repro steps

public class MyEntity
{
    public Guid Id { get; set; }
}

public class MyDbContext : DbContext
{
    public DbSet<MyEntity> MyEntities { get; init; } = default!;
}

public class MyService
{
    private readonly MyDbContext _dbContext;

    public MyService(MyDbContext dbContext) => _dbContext = dbContext;

    // This can be compiled by EF but is flagged by S6605
    public async Task DeleteEntities(List<Guid> ids)
    {
        var entitiesToDelete = await _dbContext
            .MyEntities
            .Where(e => ids.Any(i => e.Id == i))
            .ToListAsync();

        _dbContext.RemoveRange(entitiesToDelete);

        await _dbContext.SaveChangesAsync();
    }

    // This cannot be compiled by EF but is not flagged by S6605
    public async Task DeleteEntities2(List<Guid> ids)
    {
        var entitiesToDelete = await _dbContext
            .MyEntities
            .Where(e => ids.Exists(i => e.Id == i))
            .ToListAsync();

        _dbContext.RemoveRange(entitiesToDelete);

        await _dbContext.SaveChangesAsync();
    }
}

Expected behavior

Not all collection-specific methods should be used inside expressions used by EntityFramework

Actual behavior

Warning is displayed

Known workarounds

1. Suppress the warning
2. Change types passed into EF expressions to not be concrete collections, use IEnumerable<T> or ICollection<T> instead

Related information

Sonar analyzer version 9.1.0.70676

This case might also apply to other collection-specific warnings

[sebastien-marichal]

Hello @KuraiAndras,

Thank you for your feedback.

This is confirmed as a false positive.

[KuraiAndras]

Nice work guys 🚀