Fix type mappings for JSON containment functions

Fixes #1139

src/EFCore.PG/Query/ExpressionTranslators/Internal/NpgsqlJsonDbFunctionsTranslator.cs

@@ -65,13 +65,13 @@ public SqlExpression Translate(SqlExpression instance, MethodInfo method, IReadO
             {
                 nameof(NpgsqlJsonDbFunctionsExtensions.JsonContains) => new SqlCustomBinaryExpression(
                     _sqlExpressionFactory.ApplyTypeMapping(args[0], _jsonbTypeMapping),
-                    _sqlExpressionFactory.ApplyDefaultTypeMapping(args[1]),
+                    _sqlExpressionFactory.ApplyTypeMapping(args[1], _jsonbTypeMapping),
                     "@>",
                     typeof(bool),
                     _boolTypeMapping),
 
                 nameof(NpgsqlJsonDbFunctionsExtensions.JsonContained) => new SqlCustomBinaryExpression(
-                    _sqlExpressionFactory.ApplyDefaultTypeMapping(args[0]),
+                    _sqlExpressionFactory.ApplyTypeMapping(args[0], _jsonbTypeMapping),
                     _sqlExpressionFactory.ApplyTypeMapping(args[1], _jsonbTypeMapping),
                     "<@",
                     typeof(bool),

test/EFCore.PG.FunctionalTests/Query/JsonPocoQueryTest.cs

@@ -347,7 +347,7 @@ public void JsonContains_with_json_element()
         }
 
         [Fact]
-        public void JsonContains_with_string()
+        public void JsonContains_with_string_literal()
         {
             using var ctx = CreateContext();
             var count = ctx.JsonbEntities.Count(e =>
@@ -360,6 +360,24 @@ public void JsonContains_with_string()
 WHERE (j.""Customer"" @> '{""Name"": ""Joe"", ""Age"": 25}')");
         }
 
+        [Fact]
+        public void JsonContains_with_string_parameter()
+        {
+            using var ctx = CreateContext();
+            var someJson = @"{""Name"": ""Joe"", ""Age"": 25}";
+            var count = ctx.JsonbEntities.Count(e =>
+                EF.Functions.JsonContains(e.Customer, someJson));
+
+            Assert.Equal(1, count);
+            AssertSql(
+                @"@__someJson_1='{""Name"": ""Joe""
+""Age"": 25}' (DbType = Object)
+
+SELECT COUNT(*)::INT
+FROM ""JsonbEntities"" AS j
+WHERE (j.""Customer"" @> @__someJson_1)");
+        }
+
         [Fact]
         public void JsonContained_with_json_element()
         {
@@ -379,7 +397,7 @@ public void JsonContained_with_json_element()
         }
 
         [Fact]
-        public void JsonContained_with_string()
+        public void JsonContained_with_string_literal()
         {
             using var ctx = CreateContext();
             var count = ctx.JsonbEntities.Count(e =>
@@ -392,6 +410,24 @@ public void JsonContained_with_string()
 WHERE ('{""Name"": ""Joe"", ""Age"": 25}' <@ j.""Customer"")");
         }
 
+        [Fact]
+        public void JsonContained_with_string_parameter()
+        {
+            using var ctx = CreateContext();
+            var someJson = @"{""Name"": ""Joe"", ""Age"": 25}";
+            var count = ctx.JsonbEntities.Count(e =>
+                EF.Functions.JsonContained(someJson, e.Customer));
+
+            Assert.Equal(1, count);
+            AssertSql(
+                @"@__someJson_1='{""Name"": ""Joe""
+""Age"": 25}' (DbType = Object)
+
+SELECT COUNT(*)::INT
+FROM ""JsonbEntities"" AS j
+WHERE (@__someJson_1 <@ j.""Customer"")");
+        }
+
         [Fact]
         public void JsonExists()
         {