Analyzer

AvoidQuerySyntaxForSimpleExpressionAnalyzer

This is mostly a question of whether the observed behavior is by design or a bug.
In any case I'll workaround it, so don't drop everything to answer or fix/change this.

Repro steps

When doing a Cartesian product at least I find the query syntax less convoluted than the corresponding method syntax, but this triggers AV2220.

IEnumerable<int[]> QuerySyntax(int[] values)
{
    return
        from l in values
        from r in values
        select new[] { l, r };
}

IEnumerable<int[]> MethodSyntax(int[] values)
{
    return values.SelectMany(_ => values, (l, r) => new[] { l, r });
}

I found a unit test with multiple sources.
From the test name I would assume it was the use of multiple sources that made it "complex", but running the test it crosses the complexity threshold of 1 due to the where.

Removing the where brings the complexity score down to 1 which triggers the diagnostic.

Expected behavior

Whenever multiple sources are used, AV2220 is not triggered.

Actual behavior

AV2220 is triggered.