CSHARP-5473: Change Translate method to have an Expression parameter instead of an IQueryable.

Author: rstam

src/MongoDB.Driver/Linq/IMongoQueryProvider.cs

@@ -42,13 +42,13 @@ public interface IMongoQueryProvider : IQueryProvider
         Task<TResult> ExecuteAsync<TResult>(Expression expression, CancellationToken cancellationToken = default(CancellationToken));
 
         /// <summary>
-        /// Translates an IQueryable to MQL.
+        /// Translates an Expression to MQL.
         /// </summary>
-        /// <param name="queryable">The IQueryable.</param>
+        /// <param name="expression">The expression.</param>
         /// <param name="outputSerializer">The output serializer.</param>
         /// <typeparam name="TResult">The type of the result.</typeparam>
         /// <returns>An array of MQL pipeline stages represented as BsonDocuments.</returns>
-        BsonDocument[] Translate<TResult>(IQueryable<TResult> queryable, out IBsonSerializer<TResult> outputSerializer);
+        BsonDocument[] Translate<TResult>(Expression expression, out IBsonSerializer<TResult> outputSerializer);
     }
 
     /// <summary>

src/MongoDB.Driver/Linq/Linq3Implementation/MongoQueryProvider.cs

@@ -55,7 +55,7 @@ protected MongoQueryProvider(
         public abstract TResult Execute<TResult>(Expression expression);
         public abstract Task<TResult> ExecuteAsync<TResult>(Expression expression, CancellationToken cancellationToken);
         public abstract ExpressionTranslationOptions GetTranslationOptions();
-        public abstract BsonDocument[] Translate<TResult>(IQueryable<TResult> queryable, out IBsonSerializer<TResult> outputSerializer);
+        public abstract BsonDocument[] Translate<TResult>(Expression expression, out IBsonSerializer<TResult> outputSerializer);
     }
 
     internal sealed class MongoQueryProvider<TDocument> : MongoQueryProvider
@@ -154,10 +154,10 @@ public override ExpressionTranslationOptions GetTranslationOptions()
             return translationOptions.AddMissingOptionsFrom(database?.Client.Settings.TranslationOptions);
         }
 
-        public override BsonDocument[] Translate<TResult>(IQueryable<TResult> queryable, out IBsonSerializer<TResult> outputSerializer)
+        public override BsonDocument[] Translate<TResult>(Expression expression, out IBsonSerializer<TResult> outputSerializer)
         {
             var translationOptions = GetTranslationOptions();
-            var executableQuery = ExpressionToExecutableQueryTranslator.Translate<TDocument, TResult>(provider: this, queryable.Expression, translationOptions);
+            var executableQuery = ExpressionToExecutableQueryTranslator.Translate<TDocument, TResult>(provider: this, expression, translationOptions);
             var stages = executableQuery.Pipeline.Ast.Stages;
             outputSerializer = (IBsonSerializer<TResult>)executableQuery.Pipeline.OutputSerializer;
             return stages.Select(s => s.Render().AsBsonDocument).ToArray();

tests/MongoDB.Driver.Tests/Linq/Linq3Implementation/Jira/CSharp5473Tests.cs

@@ -22,36 +22,16 @@ namespace MongoDB.Driver.Tests.Linq.Linq3Implementation.Jira
 {
     public class CSharp5473Tests : Linq3IntegrationTest
     {
-        [Fact]
-        public void Translate_queryable_should_work()
-        {
-            var collection = GetCollection();
-            var queryable = collection.AsQueryable()
-                .Select(x => x.X + 1);
-            var provider = (IMongoQueryProvider)queryable.Provider;
-
-            var stages = provider.Translate(queryable, out var outputSerializer);
-            AssertStages(stages, "{ $project : { _v : { $add : ['$X', 1] }, _id : 0 } }");
-
-            var pipeline = new BsonDocumentStagePipelineDefinition<C, int>(stages, outputSerializer);
-            var result = collection.Aggregate(pipeline).Single();
-            result.Should().Be(2);
-        }
-
         [Fact]
         public void Translate_expression_should_work()
         {
             var collection = GetCollection();
             var queryable = collection.AsQueryable()
                 .Select(x => x.X + 1);
-            var expression = queryable.Expression; // collection was just used as an easy way to create the Expression
+            var expression = queryable.Expression; // queryable was just used as an easy way to create the expression and the provider
+            var provider = (IMongoQueryProvider)queryable.Provider;
 
-            // this is an example of how to translate an Expression using a dummyQueryable
-            var client = DriverTestConfiguration.Client;
-            var dummyDatabase = client.GetDatabase("dummy");
-            var dummyQueryable = dummyDatabase.AsQueryable().Provider.CreateQuery<C>(expression);
-            var provider = (IMongoQueryProvider)dummyQueryable.Provider;
-            var stages = provider.Translate(queryable, out var outputSerializer);
+            var stages = provider.Translate<int>(expression, out var outputSerializer);
             AssertStages(stages, "{ $project : { _v : { $add : ['$X', 1] }, _id : 0 } }");
 
             var pipeline = new BsonDocumentStagePipelineDefinition<C, int>(stages, outputSerializer);