Add altMessage to AssertEqualError (#550)

integration/helpers.go

@@ -124,6 +124,28 @@ func AssertEqualError(t testing.TB, expected mongo.CommandError, actual error) b
 	return assert.Equal(t, expected, a)
 }
 
+// AssertEqualAltError asserts that expected error is the same as actual
+// using altMessage for CommandError.Message if set and ignoring the Raw part.
+func AssertEqualAltError(t testing.TB, expected mongo.CommandError, altMessage string, actual error) bool {
+	t.Helper()
+
+	a, ok := actual.(mongo.CommandError)
+	if !ok {
+		return assert.Equal(t, expected, actual)
+	}
+
+	// raw part might be useful if assertion fails
+	require.Nil(t, expected.Raw)
+	expected.Raw = a.Raw
+
+	if assert.ObjectsAreEqual(expected, a) {
+		return true
+	}
+
+	expected.Message = altMessage
+	return assert.Equal(t, expected, a)
+}
+
 // CollectIDs returns all _id values from given documents.
 //
 // The order is preserved.

integration/query_test.go

@@ -252,9 +252,23 @@ func TestQueryBadSortType(t *testing.T) {
 	ctx, collection := setup(t, shareddata.Scalars, shareddata.Composites)
 
 	for name, tc := range map[string]struct {
-		command bson.D
-		err     *mongo.CommandError
+		command    bson.D
+		err        *mongo.CommandError
+		altMessage string
 	}{
+		"BadSortTypeDouble": {
+			command: bson.D{
+				{"find", collection.Name()},
+				{"projection", bson.D{{"value", "some"}}},
+				{"sort", 42.13},
+			},
+			err: &mongo.CommandError{
+				Code:    14,
+				Name:    "TypeMismatch",
+				Message: "Expected field sortto be of type object",
+			},
+			altMessage: "Expected field sort to be of type object",
+		},
 		"BadSortType": {
 			command: bson.D{
 				{"find", collection.Name()},
@@ -266,6 +280,7 @@ func TestQueryBadSortType(t *testing.T) {
 				Name:    "TypeMismatch",
 				Message: "Expected field sortto be of type object",
 			},
+			altMessage: "Expected field sort to be of type object",
 		},
 	} {
 		name, tc := name, tc
@@ -275,7 +290,7 @@ func TestQueryBadSortType(t *testing.T) {
 			var actual bson.D
 			err := collection.Database().RunCommand(ctx, tc.command).Decode(&actual)
 			require.Error(t, err)
-			AssertEqualError(t, *tc.err, err)
+			AssertEqualAltError(t, *tc.err, tc.altMessage, err)
 		})
 	}
 }

internal/handlers/pg/msg_find.go

@@ -82,7 +82,7 @@ func (h *Handler) MsgFind(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, er
 		return nil, err
 	}
 	if sort, err = common.GetOptionalParam(document, "sort", sort); err != nil {
-		return nil, common.NewErrorMsg(common.ErrTypeMismatch, "Expected field sortto be of type object")
+		return nil, common.NewErrorMsg(common.ErrTypeMismatch, "Expected field sort to be of type object")
 	}
 	if projection, err = common.GetOptionalParam(document, "projection", projection); err != nil {
 		return nil, err