CSHARP-1661: added bytes and cp variants.

Author: craiggwilson

src/MongoDB.Driver/Linq/Translators/AggregateLanguageTranslator.cs

@@ -1084,7 +1084,11 @@ private bool TryTranslateStringMethodCall(MethodCallExpression node, out BsonVal
                         indexOfArgs.Add(endIndex);
                     }
 
-                    result = new BsonDocument("$indexOfBytes", indexOfArgs);
+                    var indexOpName = _stringTranslationMode == AggregateStringTranslationMode.CodePoints ?
+                            "$indexOfCP" :
+                            "$indexOfBytes";
+
+                    result = new BsonDocument(indexOpName, indexOfArgs);
                     return true;
                 case "Split":
                     if (node.Arguments.Count < 1 || node.Arguments.Count > 2)
@@ -1127,10 +1131,10 @@ private bool TryTranslateStringMethodCall(MethodCallExpression node, out BsonVal
                 case "Substring":
                     if (node.Arguments.Count == 2)
                     {
-                        var name = _stringTranslationMode == AggregateStringTranslationMode.CodePoints ?
+                        var substrOpName = _stringTranslationMode == AggregateStringTranslationMode.CodePoints ?
                             "$substrCP" :
                             "$substr";
-                        result = new BsonDocument(name, new BsonArray(new[]
+                        result = new BsonDocument(substrOpName, new BsonArray(new[]
                             {
                                 field,
                                 TranslateValue(node.Arguments[0]),

tests/MongoDB.Driver.Tests/Linq/Translators/AggregateProjectTranslatorTests.cs

@@ -554,7 +554,7 @@ public void Should_translate_hour()
         }
 
         [SkippableFact]
-        public void Should_translate_indexOf()
+        public void Should_translate_indexOfBytes()
         {
             RequireServer.Where(minimumVersion: "3.3.6");
 
@@ -583,6 +583,36 @@ public void Should_translate_indexOf()
             result.Value.Result.Should().Be(-1);
         }
 
+        [SkippableFact]
+        public void Should_translate_indexOfCP()
+        {
+            RequireServer.Where(minimumVersion: "3.3.6");
+
+            var result = Project(x => new { Result = x.A.IndexOf('e') }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\"] }, _id: 0 }");
+            result.Value.Result.Should().Be(2);
+
+            result = Project(x => new { Result = x.A.IndexOf("e") }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\"] }, _id: 0 }");
+            result.Value.Result.Should().Be(2);
+
+            result = Project(x => new { Result = x.A.IndexOf('e', 4) }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\", 4] }, _id: 0 }");
+            result.Value.Result.Should().Be(6);
+
+            result = Project(x => new { Result = x.A.IndexOf("e", 4) }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\", 4] }, _id: 0 }");
+            result.Value.Result.Should().Be(6);
+
+            result = Project(x => new { Result = x.A.IndexOf('e', 4, 2) }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\", 4, { $add: [4, 2] }] }, _id: 0 }");
+            result.Value.Result.Should().Be(-1);
+
+            result = Project(x => new { Result = x.A.IndexOf("e", 4, 2) }, __codePointTranslationOptions);
+            result.Projection.Should().Be("{ Result: { \"$indexOfCP\": [\"$A\", \"e\", 4, { $add: [4, 2] }] }, _id: 0 }");
+            result.Value.Result.Should().Be(-1);
+        }
+
         [Fact]
         public void Should_translate_less_than()
         {