WIP pyrefly

Author: Otto-AA

e2e_projects/type_checking/pyproject.toml

@@ -21,8 +21,8 @@ dev = [
 [tool.mutmut]
 debug = true
 # TODO: pyrefly ignores mutants/ dir if it is in .gitignore
-# type_check_command = ["pyrefly", "check", "--output-format=json", "--use-ignore-files=false"]
-type_check_command = ["pyright", "--outputjson"]
+type_check_command = ["pyrefly", "check", "--output-format=json", "--use-ignore-files=false"]
+# type_check_command = ["pyright", "--outputjson"]
 
 [tool.pyrefly]
 project-includes = [

src/mutmut/__main__.py

@@ -97,7 +97,7 @@
     'timeout': '⏰',
     'suspicious': '🤔',
     'skipped': '🔇',
-    'caught by type check': 'ö',
+    'caught by type check': '🧙',
     'check was interrupted by user': '🛑',
     'not checked': '?',
     'killed': '🎉',
@@ -319,6 +319,7 @@ def __init__(self, *, path):
         self.key_by_pid = {}
         self.exit_code_by_key = {}
         self.durations_by_key = {}
+        self.type_check_error_by_key = {}
         self.hash_by_function_name = {}
         self.start_time_by_pid = {}
 
@@ -333,7 +334,8 @@ def load(self):
         self.hash_by_function_name = meta.pop('hash_by_function_name')
         self.durations_by_key = meta.pop('durations_by_key')
         self.estimated_time_of_tests_by_mutant = meta.pop('estimated_durations_by_key')
-        assert not meta, f'Meta file {self.meta_path} constains unexpected keys: {set(meta.keys())}'
+        self.type_check_error_by_key = meta.pop('type_check_error_by_key')
+        assert not meta, f'Meta file {self.meta_path} contains unexpected keys: {set(meta.keys())}'
 
     def register_pid(self, *, pid, key):
         self.key_by_pid[pid] = key
@@ -361,6 +363,7 @@ def save(self):
                 exit_code_by_key=self.exit_code_by_key,
                 hash_by_function_name=self.hash_by_function_name,
                 durations_by_key=self.durations_by_key,
+                type_check_error_by_key=self.type_check_error_by_key,
                 estimated_durations_by_key=self.estimated_time_of_tests_by_mutant,
             ), f, indent=4)
 
@@ -402,6 +405,7 @@ def filter_mutants_with_type_checker():
                 mutants_to_skip.append(FailedTypeCheckMutant(
                     method_location=mutant,
                     name=mutant_name,
+                    error=error,
                 ))
 
         return mutants_to_skip
@@ -427,6 +431,7 @@ class MutatedMethodLocation:
 class FailedTypeCheckMutant:
     method_location: MutatedMethodLocation
     name: str
+    error: TypeCheckingError
 
 
 class MutatedMethodsCollector(cst.CSTVisitor):
@@ -750,7 +755,7 @@ def calculate_summary_stats(source_file_mutation_data_by_path):
 
 def print_stats(source_file_mutation_data_by_path, force_output=False):
     s = calculate_summary_stats(source_file_mutation_data_by_path)
-    print_status(f'{(s.total - s.not_checked)}/{s.total}  🎉 {s.killed} 🫥 {s.no_tests}  ⏰ {s.timeout}  🤔 {s.suspicious}  🙁 {s.survived}  🔇 {s.skipped}  X {s.caught_by_type_check}', force_output=force_output)
+    print_status(f'{(s.total - s.not_checked)}/{s.total}  🎉 {s.killed} 🫥 {s.no_tests}  ⏰ {s.timeout}  🤔 {s.suspicious}  🙁 {s.survived}  🔇 {s.skipped}  🧙 {s.caught_by_type_check}', force_output=force_output)
 
 
 def run_forced_fail_test(runner):
@@ -1264,6 +1269,7 @@ def read_one_child_exit_status():
             failed_type_check_mutant = next((m for m in failed_type_check_mutants if m.name == mutant_name), None)
             if failed_type_check_mutant:
                 m.exit_code_by_key[mutant_name] = 6
+                m.type_check_error_by_key[mutant_name] = failed_type_check_mutant.error.error_description
                 m.save()
                 continue
 
@@ -1598,6 +1604,7 @@ def on_data_table_row_highlighted(self, event):
                 status = status_by_exit_code[exit_code]
                 estimated_duration = source_file_mutation_data.estimated_time_of_tests_by_mutant.get(mutant_name, '?')
                 duration = source_file_mutation_data.durations_by_key.get(mutant_name, '?')
+                type_check_error = source_file_mutation_data.type_check_error_by_key.get(mutant_name, '?')
 
                 view_tests_description = f'(press t to view tests executed for this mutant)'
 
@@ -1610,6 +1617,8 @@ def on_data_table_row_highlighted(self, event):
                         description = f'Skipped ({exit_code=})'
                     case 'check was interrupted by user':
                         description = f'User interrupted ({exit_code=})'
+                    case 'caught by type check':
+                        description = f'Caught by type checker ({exit_code=}): {type_check_error}'
                     case 'timeout':
                         description = (f'Timeout ({exit_code=}): Timed out because tests did not finish within {duration:.3f} seconds. '
                                             f'Tests without mutation took {estimated_duration:.3f} seconds. {view_tests_description}')

src/mutmut/file_mutation.py

@@ -10,7 +10,7 @@
 from mutmut.trampoline_templates import create_trampoline_lookup, mangle_function_name, trampoline_impl
 from mutmut.node_mutation import mutation_operators, OPERATORS_TYPE
 
-NEVER_MUTATE_FUNCTION_NAMES = { "__getattribute__", "__setattr__", "__new__", "__init__" }
+NEVER_MUTATE_FUNCTION_NAMES = { "__getattribute__", "__setattr__", "__new__"}
 NEVER_MUTATE_FUNCTION_CALLS = { "len", "isinstance" }
 
 @dataclass
@@ -158,10 +158,6 @@ def _skip_node_and_children(self, node: cst.CSTNode):
         if isinstance(node, (cst.FunctionDef, cst.ClassDef)) and len(node.decorators):
             return True
 
-        if isinstance(node, cst.ClassDef):
-            # TODO: do not skip classes for type checking
-            return True
-
         return False
 
 

tests/e2e/test_e2e_my_lib.py

@@ -1,10 +1,8 @@
-import pytest
 from inline_snapshot import snapshot
 
 from tests.e2e.e2e_utils import run_mutmut_on_project
 
 
-@pytest.mark.skip(reason="WIP type checking implementation")
 def test_my_lib_result_snapshot():
     assert run_mutmut_on_project("my_lib") == snapshot(
         {

tests/e2e/test_e2e_type_checking.py

@@ -13,6 +13,7 @@ def test_type_checking_result_snapshot():
                 "type_checking.x_hello__mutmut_4": 1,
                 "type_checking.x_a_hello_wrapper__mutmut_1": 6,
                 "type_checking.x_a_hello_wrapper__mutmut_2": 0,
+                "type_checking.xǁPersonǁset_name__mutmut_1": 6,
                 "type_checking.x_mutate_me__mutmut_1": 6,
                 "type_checking.x_mutate_me__mutmut_2": 6,
                 "type_checking.x_mutate_me__mutmut_3": 1,

tests/test_mutation regression.py

@@ -1,4 +1,3 @@
-import pytest
 from inline_snapshot import snapshot
 import libcst as cst
 
@@ -66,7 +65,6 @@ def foo(self, a, b):
 """)
 
 
-@pytest.mark.skip(reason="WIP type checking implementation")
 def test_module_mutation():
     """Regression test, for a complete module with functions, type annotations and a class"""
 
@@ -101,33 +99,33 @@ def add(self, value):
 from typing import Callable
 from typing import ClassVar
 
-MutantDict = Annotated[dict[str, Callable], "Mutant"]
+MutantDict = Annotated[dict[str, Callable], "Mutant"] # type: ignore
 
 
-def _mutmut_trampoline(orig, mutants, call_args, call_kwargs, self_arg = None):
+def _mutmut_trampoline(orig, mutants, call_args, call_kwargs, self_arg = None): # type: ignore
     """Forward call to original or mutated function, depending on the environment"""
-    import os
-    mutant_under_test = os.environ['MUTANT_UNDER_TEST']
-    if mutant_under_test == 'fail':
-        from mutmut.__main__ import MutmutProgrammaticFailException
-        raise MutmutProgrammaticFailException('Failed programmatically')      \n\
-    elif mutant_under_test == 'stats':
-        from mutmut.__main__ import record_trampoline_hit
-        record_trampoline_hit(orig.__module__ + '.' + orig.__name__)
+    import os # type: ignore
+    mutant_under_test = os.environ['MUTANT_UNDER_TEST'] # type: ignore
+    if mutant_under_test == 'fail': # type: ignore
+        from mutmut.__main__ import MutmutProgrammaticFailException # type: ignore
+        raise MutmutProgrammaticFailException('Failed programmatically')       # type: ignore
+    elif mutant_under_test == 'stats': # type: ignore
+        from mutmut.__main__ import record_trampoline_hit # type: ignore
+        record_trampoline_hit(orig.__module__ + '.' + orig.__name__) # type: ignore
         # (for class methods, orig is bound and thus does not need the explicit self argument)
-        result = orig(*call_args, **call_kwargs)
-        return result
-    prefix = orig.__module__ + '.' + orig.__name__ + '__mutmut_'
-    if not mutant_under_test.startswith(prefix):
-        result = orig(*call_args, **call_kwargs)
-        return result
-    mutant_name = mutant_under_test.rpartition('.')[-1]
-    if self_arg is not None:
+        result = orig(*call_args, **call_kwargs) # type: ignore
+        return result # type: ignore
+    prefix = orig.__module__ + '.' + orig.__name__ + '__mutmut_' # type: ignore
+    if not mutant_under_test.startswith(prefix): # type: ignore
+        result = orig(*call_args, **call_kwargs) # type: ignore
+        return result # type: ignore
+    mutant_name = mutant_under_test.rpartition('.')[-1] # type: ignore
+    if self_arg is not None: # type: ignore
         # call to a class method where self is not bound
-        result = mutants[mutant_name](self_arg, *call_args, **call_kwargs)
+        result = mutants[mutant_name](self_arg, *call_args, **call_kwargs) # type: ignore
     else:
-        result = mutants[mutant_name](*call_args, **call_kwargs)
-    return result
+        result = mutants[mutant_name](*call_args, **call_kwargs) # type: ignore
+    return result # type: ignore
 
 def x_foo__mutmut_orig(a: list[int], b):
     return a[0] > b
@@ -143,7 +141,7 @@ def foo(a: list[int], b):
     kwargs = {}
     return _mutmut_trampoline(x_foo__mutmut_orig, x_foo__mutmut_mutants, args, kwargs, None)
 
-x_foo__mutmut_mutants : ClassVar[MutantDict] = {
+x_foo__mutmut_mutants : ClassVar[MutantDict] = { # type: ignore
 'x_foo__mutmut_1': x_foo__mutmut_1, \n\
     'x_foo__mutmut_2': x_foo__mutmut_2
 }
@@ -160,7 +158,7 @@ def bar():
     kwargs = {}
     return _mutmut_trampoline(x_bar__mutmut_orig, x_bar__mutmut_mutants, args, kwargs, None)
 
-x_bar__mutmut_mutants : ClassVar[MutantDict] = {
+x_bar__mutmut_mutants : ClassVar[MutantDict] = { # type: ignore
 'x_bar__mutmut_1': x_bar__mutmut_1
 }
 x_bar__mutmut_orig.__name__ = 'x_bar'
@@ -175,7 +173,7 @@ def __init__(self, amount):
         kwargs = {}
         return _mutmut_trampoline(object.__getattribute__(self, 'xǁAdderǁ__init____mutmut_orig'), object.__getattribute__(self, 'xǁAdderǁ__init____mutmut_mutants'), args, kwargs, self)
     \n\
-    xǁAdderǁ__init____mutmut_mutants : ClassVar[MutantDict] = {
+    xǁAdderǁ__init____mutmut_mutants : ClassVar[MutantDict] = { # type: ignore
     'xǁAdderǁ__init____mutmut_1': xǁAdderǁ__init____mutmut_1
     }
     xǁAdderǁ__init____mutmut_orig.__name__ = 'xǁAdderǁ__init__'
@@ -191,7 +189,7 @@ def add(self, value):
         kwargs = {}
         return _mutmut_trampoline(object.__getattribute__(self, 'xǁAdderǁadd__mutmut_orig'), object.__getattribute__(self, 'xǁAdderǁadd__mutmut_mutants'), args, kwargs, self)
     \n\
-    xǁAdderǁadd__mutmut_mutants : ClassVar[MutantDict] = {
+    xǁAdderǁadd__mutmut_mutants : ClassVar[MutantDict] = { # type: ignore
     'xǁAdderǁadd__mutmut_1': xǁAdderǁadd__mutmut_1
     }
     xǁAdderǁadd__mutmut_orig.__name__ = 'xǁAdderǁadd'

tests/test_mutation.py

@@ -4,8 +4,6 @@
 from unittest.mock import Mock, patch
 
 import libcst as cst
-import pytest
-from inline_snapshot import snapshot
 
 import mutmut
 from mutmut.__main__ import (
@@ -303,7 +301,6 @@ def concat():
     assert sorted(mutants) == []
 
 
-@pytest.mark.skip(reason="WIP type checking implementation")
 def test_basic_class():
     source = """
 class Foo:
@@ -493,7 +490,6 @@ def test_mangle_function_name():
     assert mangle_function_name(name='bar', class_name='Foo') == f'x{CLASS_NAME_SEPARATOR}Foo{CLASS_NAME_SEPARATOR}bar'
 
 
-@pytest.mark.skip(reason="WIP type checking implementation")
 def test_diff_ops():
     source = """
 def foo():    
@@ -641,8 +637,7 @@ def x(self):
     assert not mutants
 
 
-# TODO: implement removal of inner decorators
-@pytest.mark.skip
+@pytest.mark.skip(reason="Feature not yet implemented")
 def test_decorated_inner_functions_mutation():
     source = """
 def foo():