Merge pull request #2 from Yunirang/dev1

Merging improved error logged messages for parameterized testing

src/_pytest/mark/structures.py

@@ -165,22 +165,20 @@ class ParameterSet(NamedTuple):
             # Check all parameter sets have the correct number of values.
             for param in parameters:
                 if len(param.values) != len(argnames):
+                    # Construct a string representation of the expected parameter names
+                    expected_argnames = ", ".join(argnames)
+                    # Construct a string representation of the provided parameter values
+                    provided_values = ", ".join(map(repr, param.values))
                     msg = (
-                        '{nodeid}: in "parametrize" the number of names ({names_len}):\n'
-                        "  {names}\n"
-                        "must be equal to the number of values ({values_len}):\n"
-                        "  {values}"
-                    )
-                    fail(
-                        msg.format(
-                            nodeid=nodeid,
-                            values=param.values,
-                            names=argnames,
-                            names_len=len(argnames),
-                            values_len=len(param.values),
-                        ),
-                        pytrace=False,
+                        f'{nodeid}: \n\n Error in parameterization for test "{func.__name__}".\n '
+                        f"The number of specified parameters ({len(argnames)}) "
+                        f"does not match the number of provided values ({len(param.values)}): {provided_values}. \n"
+                        f" Please ensure that the correct number of parameter names "
+                        f"({len(param.values)}) are separated by commas within quotes.\n\n"
+                        f'Require more than parameter names: "{expected_argnames}"'
                     )
+
+                    fail(msg, pytrace=False)
         else:
             # Empty parameter set (likely computed at runtime): create a single
             # parameter set with NOTSET values, with the "empty parameter set" mark applied to it.

src/_pytest/python.py

@@ -1371,8 +1371,15 @@ class Metafunc:
 
         # num_ids == 0 is a special case: https://github.com/pytest-dev/pytest/issues/1849
         if num_ids != len(parametersets) and num_ids != 0:
-            msg = "In {}: {} parameter sets specified, with different number of ids: {}"
-            fail(msg.format(func_name, len(parametersets), num_ids), pytrace=False)
+            # Construct a string representation of the expected parameter sets
+            expected_paramsets = len(parametersets)
+
+            msg = (
+                f"In {func_name}: \n\n"
+                f" Specified {expected_paramsets} parameter sets with {num_ids} different ids. \n"
+                f" Ensure all subparameters are correctly grouped within a single set of quotation marks."
+            )
+            fail(msg, pytrace=False)
 
         return list(itertools.islice(ids, num_ids))
 
@@ -1402,8 +1409,24 @@ class Metafunc:
             arg_directness = dict.fromkeys(argnames, "direct")
             for arg in indirect:
                 if arg not in argnames:
+                    # Construct a list of valid parameter names
+                    valid_params = ", ".join([f'"{name}"' for name in argnames])
+
+                    # Construct a string representing the expected number of parameters
+                    expected_param_count = len(indirect[0])
+
+                    # Construct a string representing the actual number of parameters provided
+                    actual_param_count = len(argnames)
+
                     fail(
-                        f"In {self.function.__name__}: indirect fixture '{arg}' doesn't exist",
+                        f"In function {self.function.__name__}: {argnames} is not a valid parameter. \n"
+                        f"Expected {expected_param_count} sub parameters, "
+                        f"but only {actual_param_count} were provided. \n\n"
+                        f"Make sure to pass parameter names as strings without quotes, separated by commas, \n "
+                        f"e.g., '@pytest.mark.parametrize({valid_params}, <Input Values>)'"
+                        f"\n\n"
+                        f"Or if multiple parameters are used, separate them by commas. \n "
+                        f"e.g., '@pytest.mark.parametrize(\"arg1, arg2\", <Input Tuples>)'",
                         pytrace=False,
                     )
                 arg_directness[arg] = "indirect"

testing/test_mark.py

@@ -404,6 +404,35 @@ def test_parametrized_collected_from_command_line(pytester: Pytester) -> None:
     rec.assertoutcome(passed=3)
 
 
+def test_parametrized_collect_with_wrong_format(pytester: Pytester) -> None:
+    """Parametrized test argument format not intuitive
+    line issue#8593"""
+    py_file = pytester.makepyfile(
+        """
+        import pytest
+
+        @pytest.mark.parametrize("arg1", "arg2", [(1, 1)])
+        def test_parametrization(arg1: int, arg2: int) -> None:
+            assert arg1 == arg2
+            assert arg1 + 1 == arg2 + 1
+    """
+    )
+
+    result = pytester.runpytest(py_file)
+    result.stdout.fnmatch_lines(
+        [
+            "In function test_parametrization: ['arg1'] is not a valid parameter. ",
+            "Expected 2 sub parameters, but only 1 were provided. ",
+            "",
+            "Make sure to pass parameter names as strings without quotes, separated by commas, ",
+            " e.g., '@pytest.mark.parametrize(\"arg1\", <Input Values>)'",
+            "",
+            "Or if multiple parameters are used, separate them by commas. ",
+            " e.g., '@pytest.mark.parametrize(\"arg1, arg2\", <Input Tuples>)'",
+        ]
+    )
+
+
 def test_parametrized_collect_with_wrong_args(pytester: Pytester) -> None:
     """Test collect parametrized func with wrong number of args."""
     py_file = pytester.makepyfile(
@@ -419,10 +448,13 @@ def test_parametrized_collect_with_wrong_args(pytester: Pytester) -> None:
     result = pytester.runpytest(py_file)
     result.stdout.fnmatch_lines(
         [
-            'test_parametrized_collect_with_wrong_args.py::test_func: in "parametrize" the number of names (2):',
-            "  ['foo', 'bar']",
-            "must be equal to the number of values (3):",
-            "  (1, 2, 3)",
+            "test_parametrized_collect_with_wrong_args.py::test_func: ",
+            "",
+            ' Error in parameterization for test "test_func".',
+            " The number of specified parameters (2) does not match the number of provided values (3): 1, 2, 3. ",
+            " Please ensure that the correct number of parameter names (3) are separated by commas within quotes.",
+            "",
+            'Require more than parameter names: "foo, bar"',
         ]
     )