tests for empty query

Author: zachmu

testing/go/framework.go

@@ -129,6 +129,9 @@ type ScriptTestAssertion struct {
 	CopyFromStdInFile string
 }
 
+// EmptyCommandTag is special command tag placeholder to check for the empty string
+const EmptyCommandTag = "EMPTY_COMMAND_TAG"
+
 // Connection contains the default and current connections.
 type Connection struct {
 	Default  *pgx.Conn
@@ -249,10 +252,14 @@ func runScript(t *testing.T, ctx context.Context, script ScriptTest, conn *Conne
 					require.NoError(t, err)
 				}
 			} else if assertion.ExpectedTag != "" {
-				// check for command tag
 				commandTag, err := conn.Exec(ctx, assertion.Query)
 				require.NoError(t, err)
-				assert.Equal(t, assertion.ExpectedTag, commandTag.String())
+				tag := assertion.ExpectedTag
+				if tag == EmptyCommandTag {
+					tag = ""
+				}
+
+				assert.Equal(t, tag, commandTag.String())
 			} else {
 				rows, err := conn.Query(ctx, assertion.Query, assertion.BindVars...)
 				require.NoError(t, err)

testing/go/smoke_test.go

@@ -743,26 +743,26 @@ func TestSmokeTests(t *testing.T) {
 			SetUpScript: []string{
 				"CREATE TABLE test (pk INT8 PRIMARY KEY);",
 				"INSERT INTO test VALUES " +
-					"(1),   (2),   (3),   (4),   (5),   (6),   (7),   (8),   (9),   (10)," +
-					"(11),  (12),  (13),  (14),  (15),  (16),  (17),  (18),  (19),  (20)," +
-					"(21),  (22),  (23),  (24),  (25),  (26),  (27),  (28),  (29),  (30)," +
-					"(31),  (32),  (33),  (34),  (35),  (36),  (37),  (38),  (39),  (40)," +
-					"(41),  (42),  (43),  (44),  (45),  (46),  (47),  (48),  (49),  (50)," +
-					"(51),  (52),  (53),  (54),  (55),  (56),  (57),  (58),  (59),  (60)," +
-					"(61),  (62),  (63),  (64),  (65),  (66),  (67),  (68),  (69),  (70)," +
-					"(71),  (72),  (73),  (74),  (75),  (76),  (77),  (78),  (79),  (80)," +
-					"(81),  (82),  (83),  (84),  (85),  (86),  (87),  (88),  (89),  (90)," +
-					"(91),  (92),  (93),  (94),  (95),  (96),  (97),  (98),  (99),  (100)," +
-					"(101), (102), (103), (104), (105), (106), (107), (108), (109), (110)," +
-					"(111), (112), (113), (114), (115), (116), (117), (118), (119), (120)," +
-					"(121), (122), (123), (124), (125), (126), (127), (128), (129), (130)," +
-					"(131), (132), (133), (134), (135), (136), (137), (138), (139), (140)," +
-					"(141), (142), (143), (144), (145), (146), (147), (148), (149), (150)," +
-					"(151), (152), (153), (154), (155), (156), (157), (158), (159), (160)," +
-					"(161), (162), (163), (164), (165), (166), (167), (168), (169), (170)," +
-					"(171), (172), (173), (174), (175), (176), (177), (178), (179), (180)," +
-					"(181), (182), (183), (184), (185), (186), (187), (188), (189), (190)," +
-					"(191), (192), (193), (194), (195), (196), (197), (198), (199), (200);",
+						"(1),   (2),   (3),   (4),   (5),   (6),   (7),   (8),   (9),   (10)," +
+						"(11),  (12),  (13),  (14),  (15),  (16),  (17),  (18),  (19),  (20)," +
+						"(21),  (22),  (23),  (24),  (25),  (26),  (27),  (28),  (29),  (30)," +
+						"(31),  (32),  (33),  (34),  (35),  (36),  (37),  (38),  (39),  (40)," +
+						"(41),  (42),  (43),  (44),  (45),  (46),  (47),  (48),  (49),  (50)," +
+						"(51),  (52),  (53),  (54),  (55),  (56),  (57),  (58),  (59),  (60)," +
+						"(61),  (62),  (63),  (64),  (65),  (66),  (67),  (68),  (69),  (70)," +
+						"(71),  (72),  (73),  (74),  (75),  (76),  (77),  (78),  (79),  (80)," +
+						"(81),  (82),  (83),  (84),  (85),  (86),  (87),  (88),  (89),  (90)," +
+						"(91),  (92),  (93),  (94),  (95),  (96),  (97),  (98),  (99),  (100)," +
+						"(101), (102), (103), (104), (105), (106), (107), (108), (109), (110)," +
+						"(111), (112), (113), (114), (115), (116), (117), (118), (119), (120)," +
+						"(121), (122), (123), (124), (125), (126), (127), (128), (129), (130)," +
+						"(131), (132), (133), (134), (135), (136), (137), (138), (139), (140)," +
+						"(141), (142), (143), (144), (145), (146), (147), (148), (149), (150)," +
+						"(151), (152), (153), (154), (155), (156), (157), (158), (159), (160)," +
+						"(161), (162), (163), (164), (165), (166), (167), (168), (169), (170)," +
+						"(171), (172), (173), (174), (175), (176), (177), (178), (179), (180)," +
+						"(181), (182), (183), (184), (185), (186), (187), (188), (189), (190)," +
+						"(191), (192), (193), (194), (195), (196), (197), (198), (199), (200);",
 			},
 			Assertions: []ScriptTestAssertion{
 				{
@@ -823,3 +823,25 @@ func TestSmokeTests(t *testing.T) {
 		},
 	})
 }
+
+func TestEmptyQuery(t *testing.T) {
+	RunScripts(t, []ScriptTest{
+		{
+			// TODO: we want to be able to assert that the empty query returns a specific postgres backend message,
+			//  EmptyQueryResponse. The pg library automatically converts this response to an empty-string CommandTag,
+			//  which we can't tell apart from other empty CommandTag responses. We do assert that the command tag is empty,
+			//  but it would nice to be able to assert a particular message type.
+			Name: "Empty query test",
+			Assertions: []ScriptTestAssertion{
+				{
+					Query:       ";",
+					ExpectedTag: EmptyCommandTag,
+				},
+				{
+					Query:       " ",
+					ExpectedTag: EmptyCommandTag,
+				},
+			},
+		},
+	})
+}