gh-107614: Normalise Argument Clinic error messages (#107615)

- always wrap the offending line, token, or name in quotes
- in most cases, put the entire error message on one line

Added tests for uncovered branches that were touched by this PR.

Co-authored-by: Alex Waygood <[email protected]>

Author: erlend-aasland

Lib/test/test_clinic.py

@@ -161,11 +161,8 @@ def test_checksum_mismatch(self):
             [clinic start generated code]*/
             /*[clinic end generated code: output=0123456789abcdef input=fedcba9876543210]*/
         """
-        err = (
-            'Checksum mismatch!\n'
-            'Expected: 0123456789abcdef\n'
-            'Computed: da39a3ee5e6b4b0d\n'
-        )
+        err = ("Checksum mismatch! "
+               "Expected '0123456789abcdef', computed 'da39a3ee5e6b4b0d'")
         self.expect_failure(raw, err, filename="test.c", lineno=3)
 
     def test_garbage_after_stop_line(self):
@@ -403,7 +400,7 @@ def test_clone_mismatch(self):
         self.expect_failure(block, err, lineno=9)
 
     def test_badly_formed_return_annotation(self):
-        err = "Badly formed annotation for m.f: 'Custom'"
+        err = "Badly formed annotation for 'm.f': 'Custom'"
         block = """
             /*[python input]
             class Custom_return_converter(CReturnConverter):
@@ -509,6 +506,15 @@ def test_dest_buffer_not_empty_at_eof(self):
         self.assertIn(expected_warning, stdout.getvalue())
         self.assertEqual(generated, expected_generated)
 
+    def test_dest_clear(self):
+        err = "Can't clear destination 'file': it's not of type 'buffer'"
+        block = """
+            /*[clinic input]
+            destination file clear
+            [clinic start generated code]*/
+        """
+        self.expect_failure(block, err, lineno=2)
+
     def test_directive_set_misuse(self):
         err = "unknown variable 'ets'"
         block = """
@@ -598,7 +604,7 @@ def test_directive_printout(self):
         self.assertEqual(generated, expected)
 
     def test_directive_preserve_twice(self):
-        err = "Can't have preserve twice in one block!"
+        err = "Can't have 'preserve' twice in one block!"
         block = """
             /*[clinic input]
             preserve
@@ -637,13 +643,24 @@ def test_directive_preserve_output(self):
         self.assertEqual(generated, block)
 
     def test_directive_output_invalid_command(self):
-        err = (
-            "Invalid command / destination name 'cmd', must be one of:\n"
-            "  preset push pop print everything cpp_if docstring_prototype "
-            "docstring_definition methoddef_define impl_prototype "
-            "parser_prototype parser_definition cpp_endif methoddef_ifndef "
-            "impl_definition"
-        )
+        err = dedent("""
+            Invalid command or destination name 'cmd'. Must be one of:
+             - 'preset'
+             - 'push'
+             - 'pop'
+             - 'print'
+             - 'everything'
+             - 'cpp_if'
+             - 'docstring_prototype'
+             - 'docstring_definition'
+             - 'methoddef_define'
+             - 'impl_prototype'
+             - 'parser_prototype'
+             - 'parser_definition'
+             - 'cpp_endif'
+             - 'methoddef_ifndef'
+             - 'impl_definition'
+        """).strip()
         block = """
             /*[clinic input]
             output cmd buffer
@@ -919,7 +936,7 @@ def test_param_default_expr_named_constant(self):
         self.assertEqual("MAXSIZE", p.converter.c_default)
 
         err = (
-            "When you specify a named constant ('sys.maxsize') as your default value,\n"
+            "When you specify a named constant ('sys.maxsize') as your default value, "
             "you MUST specify a valid c_default."
         )
         block = """
@@ -931,7 +948,7 @@ def test_param_default_expr_named_constant(self):
 
     def test_param_default_expr_binop(self):
         err = (
-            "When you specify an expression ('a + b') as your default value,\n"
+            "When you specify an expression ('a + b') as your default value, "
             "you MUST specify a valid c_default."
         )
         block = """
@@ -954,7 +971,7 @@ def test_param_no_docstring(self):
 
     def test_param_default_parameters_out_of_order(self):
         err = (
-            "Can't have a parameter without a default ('something_else')\n"
+            "Can't have a parameter without a default ('something_else') "
             "after a parameter with a default!"
         )
         block = """
@@ -1088,7 +1105,7 @@ def test_return_converter_invalid_syntax(self):
             module os
             os.stat -> invalid syntax
         """
-        err = "Badly formed annotation for os.stat: 'invalid syntax'"
+        err = "Badly formed annotation for 'os.stat': 'invalid syntax'"
         self.expect_failure(block, err)
 
     def test_legacy_converter_disallowed_in_return_annotation(self):
@@ -1252,8 +1269,8 @@ def test_nested_groups(self):
 
     def test_disallowed_grouping__two_top_groups_on_left(self):
         err = (
-            'Function two_top_groups_on_left has an unsupported group '
-            'configuration. (Unexpected state 2.b)'
+            "Function 'two_top_groups_on_left' has an unsupported group "
+            "configuration. (Unexpected state 2.b)"
         )
         block = """
             module foo
@@ -1281,7 +1298,7 @@ def test_disallowed_grouping__two_top_groups_on_right(self):
                 ]
         """
         err = (
-            "Function two_top_groups_on_right has an unsupported group "
+            "Function 'two_top_groups_on_right' has an unsupported group "
             "configuration. (Unexpected state 6.b)"
         )
         self.expect_failure(block, err)
@@ -1317,7 +1334,7 @@ def test_disallowed_grouping__group_after_parameter_on_left(self):
                 param: int
         """
         err = (
-            "Function group_after_parameter_on_left has an unsupported group "
+            "Function 'group_after_parameter_on_left' has an unsupported group "
             "configuration. (Unexpected state 2.b)"
         )
         self.expect_failure(block, err)
@@ -1334,7 +1351,7 @@ def test_disallowed_grouping__empty_group_on_left(self):
                 param: int
         """
         err = (
-            "Function empty_group has an empty group.\n"
+            "Function 'empty_group' has an empty group. "
             "All groups must contain at least one parameter."
         )
         self.expect_failure(block, err)
@@ -1351,7 +1368,7 @@ def test_disallowed_grouping__empty_group_on_right(self):
                 ]
         """
         err = (
-            "Function empty_group has an empty group.\n"
+            "Function 'empty_group' has an empty group. "
             "All groups must contain at least one parameter."
         )
         self.expect_failure(block, err)
@@ -1365,7 +1382,7 @@ def test_disallowed_grouping__no_matching_bracket(self):
                 group2: int
                 ]
         """
-        err = "Function empty_group has a ] without a matching [."
+        err = "Function 'empty_group' has a ']' without a matching '['"
         self.expect_failure(block, err)
 
     def test_no_parameters(self):
@@ -1400,7 +1417,7 @@ def test_illegal_module_line(self):
             foo.bar => int
                 /
         """
-        err = "Illegal function name: foo.bar => int"
+        err = "Illegal function name: 'foo.bar => int'"
         self.expect_failure(block, err)
 
     def test_illegal_c_basename(self):
@@ -1409,7 +1426,7 @@ def test_illegal_c_basename(self):
             foo.bar as 935
                 /
         """
-        err = "Illegal C basename: 935"
+        err = "Illegal C basename: '935'"
         self.expect_failure(block, err)
 
     def test_single_star(self):
@@ -1419,7 +1436,7 @@ def test_single_star(self):
                 *
                 *
         """
-        err = "Function bar uses '*' more than once."
+        err = "Function 'bar' uses '*' more than once."
         self.expect_failure(block, err)
 
     def test_parameters_required_after_star(self):
@@ -1429,7 +1446,7 @@ def test_parameters_required_after_star(self):
             "module foo\nfoo.bar\n  this: int\n  *",
             "module foo\nfoo.bar\n  this: int\n  *\nDocstring.",
         )
-        err = "Function bar specifies '*' without any parameters afterwards."
+        err = "Function 'bar' specifies '*' without any parameters afterwards."
         for block in dataset:
             with self.subTest(block=block):
                 self.expect_failure(block, err)
@@ -1442,7 +1459,7 @@ def test_single_slash(self):
                 /
         """
         err = (
-            "Function bar has an unsupported group configuration. "
+            "Function 'bar' has an unsupported group configuration. "
             "(Unexpected state 0.d)"
         )
         self.expect_failure(block, err)
@@ -1456,7 +1473,7 @@ def test_double_slash(self):
                 b: int
                 /
         """
-        err = "Function bar uses '/' more than once."
+        err = "Function 'bar' uses '/' more than once."
         self.expect_failure(block, err)
 
     def test_mix_star_and_slash(self):
@@ -1470,7 +1487,7 @@ def test_mix_star_and_slash(self):
                /
         """
         err = (
-            "Function bar mixes keyword-only and positional-only parameters, "
+            "Function 'bar' mixes keyword-only and positional-only parameters, "
             "which is unsupported."
         )
         self.expect_failure(block, err)
@@ -1483,7 +1500,7 @@ def test_parameters_not_permitted_after_slash_for_now(self):
                 x: int
         """
         err = (
-            "Function bar has an unsupported group configuration. "
+            "Function 'bar' has an unsupported group configuration. "
             "(Unexpected state 0.d)"
         )
         self.expect_failure(block, err)
@@ -1582,7 +1599,8 @@ def test_indent_stack_no_tabs(self):
                *vararg1: object
             \t*vararg2: object
         """
-        err = "Tab characters are illegal in the Clinic DSL."
+        err = ("Tab characters are illegal in the Clinic DSL: "
+               r"'\t*vararg2: object'")
         self.expect_failure(block, err)
 
     def test_indent_stack_illegal_outdent(self):
@@ -1841,16 +1859,25 @@ def test_vararg_cannot_take_default_value(self):
         """
         self.expect_failure(block, err, lineno=1)
 
+    def test_default_is_not_of_correct_type(self):
+        err = ("int_converter: default value 2.5 for field 'a' "
+               "is not of type 'int'")
+        block = """
+            fn
+                a: int = 2.5
+        """
+        self.expect_failure(block, err, lineno=1)
+
     def test_invalid_legacy_converter(self):
-        err = "fhi is not a valid legacy converter"
+        err = "'fhi' is not a valid legacy converter"
         block = """
             fn
                 a: 'fhi'
         """
         self.expect_failure(block, err, lineno=1)
 
     def test_parent_class_or_module_does_not_exist(self):
-        err = "Parent class or module z does not exist"
+        err = "Parent class or module 'z' does not exist"
         block = """
             module m
             z.func
@@ -1877,7 +1904,7 @@ def test_param_requires_custom_c_name(self):
         self.expect_failure(block, err, lineno=2)
 
     def test_state_func_docstring_assert_no_group(self):
-        err = "Function func has a ] without a matching [."
+        err = "Function 'func' has a ']' without a matching '['"
         block = """
             module m
             m.func
@@ -1887,7 +1914,7 @@ def test_state_func_docstring_assert_no_group(self):
         self.expect_failure(block, err, lineno=2)
 
     def test_state_func_docstring_no_summary(self):
-        err = "Docstring for m.func does not have a summary line!"
+        err = "Docstring for 'm.func' does not have a summary line!"
         block = """
             module m
             m.func
@@ -1983,13 +2010,11 @@ def test_cli_force(self):
             const char *hand_edited = "output block is overwritten";
             /*[clinic end generated code: output=bogus input=bogus]*/
         """)
-        fail_msg = dedent("""
-            Checksum mismatch!
-            Expected: bogus
-            Computed: 2ed19
-            Suggested fix: remove all generated code including the end marker,
-            or use the '-f' option.
-        """)
+        fail_msg = (
+            "Checksum mismatch! Expected 'bogus', computed '2ed19'. "
+            "Suggested fix: remove all generated code including the end marker, "
+            "or use the '-f' option.\n"
+        )
         with os_helper.temp_dir() as tmp_dir:
             fn = os.path.join(tmp_dir, "test.c")
             with open(fn, "w", encoding="utf-8") as f:
@@ -2214,7 +2239,7 @@ def test_file_dest(self):
                 f.write("")  # Write an empty output file!
             # Clinic should complain about the empty output file.
             _, err = self.expect_failure(in_fn)
-            expected_err = (f"Modified destination file {out_fn!r}, "
+            expected_err = (f"Modified destination file {out_fn!r}; "
                             "not overwriting!")
             self.assertIn(expected_err, err)
             # Run clinic again, this time with the -f option.