Query: Apply optimizations to composite predicates in all parts of the query

[maumar]

Currently CompositePredicateExpressionVisitor is only applied to predicates. Perhaps some of the work we do there could be applied in other places (e.g projections)

[smitpatel]

See Tests
Optional_navigation_type_compensation_works_with_contains
Any_with_optional_navigation_as_subquery_predicate_is_translated_to_sql
All_with_optional_navigation_is_translated_to_sql
Optional_navigation_type_compensation_works_with_all

Assert.Equal(
                @"SELECT CASE
    WHEN NOT EXISTS (
        SELECT 1
        FROM [CogTag] AS [t]
        LEFT JOIN (
            SELECT [t.Gear].[Nickname], [t.Gear].[SquadId], [t.Gear].[AssignedCityName], [t.Gear].[CityOrBirthName], [t.Gear].[Discriminator], [t.Gear].[FullName], [t.Gear].[HasSoulPatch], [t.Gear].[LeaderNickname], [t.Gear].[LeaderSquadId], [t.Gear].[Rank]
            FROM [Gear] AS [t.Gear]
            WHERE ([t.Gear].[Discriminator] = N'Officer') OR ([t.Gear].[Discriminator] = N'Gear') //<--- BAD LINE
        ) AS [t0] ON ([t].[GearNickName] = [t0].[Nickname]) AND ([t].[GearSquadId] = [t0].[SquadId])
        WHERE (([t].[Note] <> N'K.I.A.') OR [t].[Note] IS NULL) AND ([t0].[HasSoulPatch] = 0))
    THEN CAST(1 AS BIT) ELSE CAST(0 AS BIT)
END",
                Sql);

[smitpatel]

Can I poach this?

[smitpatel]

This is already fixed in latest dev. The issue in above query was, we had to go inside of ExistExpression. It was missing proper VisitChildren method. Which was done in #7646 Thanks @tuespetre