Fixes SelectMany,

n9 · May 1, 2019 · 9f3d69d · 9f3d69d
1 parent 2f55786
commit 9f3d69d
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Showing 2 changed files with 21 additions and 4 deletions.
diff --git a/src/CouchDB.Driver/CouchQueryProvider.cs b/src/CouchDB.Driver/CouchQueryProvider.cs
@@ -157,6 +157,16 @@ bool IsCorrectMethod(MethodInfo m)
                 {
                     return false;
                 }
+
+                if (methodInfo.ReturnType != m.ReturnType)
+                {
+                    if (!methodInfo.ReturnType.IsGenericParameter && !typeof(IQueryable<>).IsAssignableFrom(methodInfo.ReturnType) &&
+                        !m.ReturnType.IsGenericParameter && !typeof(IEnumerable<>).IsAssignableFrom(m.ReturnType))
+                    {
+                        return false;
+                    }
+                }
+
                 for (var i = 1; i < parameters.Length; i++)
                 {
                     Expression currentExpression = methodArguments[i];
@@ -176,9 +186,14 @@ bool IsCorrectMethod(MethodInfo m)
                         ReadOnlyCollection<ParameterExpression> lambdaParameters = l.Parameters;
                         Type lambdaReturnType = l.ReturnType;
 
+                        if (currentParamType.Length - 1 > lambdaParameters.Count)
+                        {
+                            return false;
+                        }
+
                         // The return type must be the same
                         var enumerableReturnType = currentParamType[currentParamType.Length - 1];
-                        if (!enumerableReturnType.IsGenericParameter && enumerableReturnType != lambdaReturnType)
+                        if (!enumerableReturnType.IsGenericType && !enumerableReturnType.IsGenericParameter && enumerableReturnType != lambdaReturnType)
                         {
                             return false;
                         }
@@ -202,7 +217,8 @@ bool IsCorrectMethod(MethodInfo m)
                 return true;
             }
 
-            MethodInfo enumarableMethod = typeof(Enumerable).GetMethods().SingleOrDefault(IsCorrectMethod);
+            var enumarableMethods = typeof(Enumerable).GetMethods().Where(IsCorrectMethod).ToList();
+            MethodInfo enumarableMethod = enumarableMethods.First();
             if (enumarableMethod == null)
             {
                 throw new NotSupportedException($"The method '{methodInfo.Name}' is not supported");

diff --git a/tests/CouchDB.Driver.E2ETests/Client_Tests.cs b/tests/CouchDB.Driver.E2ETests/Client_Tests.cs
@@ -87,9 +87,10 @@ public async Task InMemoryLINQ()
                 Rebel luke = await rebels.CreateAsync(new Rebel { Name = "Luke", Age = 19 }).ConfigureAwait(false);
                 Assert.Equal("Luke", luke.Name);
 
-                luke = rebels
+                var x = rebels
                     .Where(c => c.Name == "Luke").Take(1) // Couch query
-                    .GroupBy(e => e.Name).OrderBy(g => g.Key).First().First(); // In-memory
+                    .GroupBy(e => e.Name).OrderBy(g => g.Key).SelectMany(g => g)
+                    .Average(g => g.Age); // In-memory
                 Assert.Equal(19, luke.Age);
 
                 await client.DeleteDatabaseAsync<Rebel>().ConfigureAwait(false);