unify DataDrivenTestCase classes (#5013)

Author: elazarg

mypy/test/data.py

@@ -28,20 +28,16 @@
 FileOperation = Union[UpdateFile, DeleteFile]
 
 
-def parse_test_cases(
-        path: str,
-        base_path: str = '.',
-        optional_out: bool = False,
-        native_sep: bool = False) -> List['DataDrivenTestCase']:
-    """Parse a file with test case descriptions.
-
-    Return an array of test cases.
+def parse_test_cases(parent: 'DataSuiteCollector', suite: 'DataSuite',
+                     path: str) -> Iterator['DataDrivenTestCase']:
+    """Parse a single file from suite with test case descriptions.
 
     NB: this function and DataDrivenTestCase were shared between the
     myunit and pytest codepaths -- if something looks redundant,
     that's likely the reason.
     """
-    if native_sep:
+    base_path = suite.base_path
+    if suite.native_sep:
         join = os.path.join
     else:
         join = posixpath.join  # type: ignore
@@ -51,7 +47,6 @@ def parse_test_cases(
     for i in range(len(lst)):
         lst[i] = lst[i].rstrip('\n')
     p = parse_test_data(lst, path)
-    out = []  # type: List[DataDrivenTestCase]
 
     # Process the parsed items. Each item has a header of form [id args],
     # optionally followed by lines of text.
@@ -143,7 +138,7 @@ def parse_test_cases(
                     assert passnum > 1
                     output = p[i].data
                     output = [expand_variables(line) for line in output]
-                    if native_sep and os.path.sep == '\\':
+                    if suite.native_sep and os.path.sep == '\\':
                         output = [fix_win_path(line) for line in output]
                     tcout2[passnum] = output
                     ok = True
@@ -167,7 +162,7 @@ def parse_test_cases(
                         ('Stale modules after pass {} must be a subset of rechecked '
                          'modules ({}:{})').format(passnum, path, p[i0].line))
 
-            if optional_out:
+            if suite.optional_out:
                 ok = True
 
             if ok:
@@ -178,24 +173,24 @@ def parse_test_cases(
                 lastline = p[i].line if i < len(p) else p[i - 1].line + 9999
                 arg0 = p[i0].arg
                 assert arg0 is not None
-                tc = DataDrivenTestCase(arg0, input, tcout, tcout2, path,
-                                        p[i0].line, lastline,
-                                        files, output_files, stale_modules,
-                                        rechecked_modules, deleted_paths, native_sep,
-                                        triggered)
-                out.append(tc)
+                case_name = add_test_name_suffix(arg0, suite.test_name_suffix)
+                skip = arg0.endswith('-skip')
+                if skip:
+                    case_name = case_name[:-len('-skip')]
+                yield DataDrivenTestCase(case_name, parent, skip, input, tcout, tcout2, path,
+                                         p[i0].line, lastline,
+                                         files, output_files, stale_modules,
+                                         rechecked_modules, deleted_paths, suite.native_sep,
+                                         triggered)
         if not ok:
             raise ValueError(
                 '{}, line {}: Error in test case description'.format(
                     path, p[i0].line))
 
-    return out
-
 
-class DataDrivenTestCase:
-    """Holds parsed data and handles directory setup and teardown for MypyDataCase."""
+class DataDrivenTestCase(pytest.Item):  # type: ignore  # inheriting from Any
+    """Holds parsed data-driven test cases, and handles directory setup and teardown."""
 
-    # TODO: rename to ParsedTestCase or merge with MypyDataCase (yet avoid multiple inheritance)
     # TODO: only create files on setup, not during parsing
 
     input = None  # type: List[str]
@@ -215,6 +210,8 @@ class DataDrivenTestCase:
 
     def __init__(self,
                  name: str,
+                 parent: 'DataSuiteCollector',
+                 skip: bool,
                  input: List[str],
                  output: List[str],
                  output2: Dict[int, List[str]],
@@ -229,7 +226,9 @@ def __init__(self,
                  native_sep: bool = False,
                  triggered: Optional[List[str]] = None,
                  ) -> None:
-        self.name = name
+
+        super().__init__(name, parent)
+        self.skip = skip
         self.old_cwd = None  # type: Optional[str]
         self.tmpdir = None  # type: Optional[tempfile.TemporaryDirectory[str]]
         self.input = input
@@ -246,6 +245,14 @@ def __init__(self,
         self.native_sep = native_sep
         self.triggered = triggered or []
 
+    def runtest(self) -> None:
+        if self.skip:
+            pytest.skip()
+        suite = self.parent.obj()
+        suite.update_data = self.config.getoption('--update-data', False)
+        suite.setup()
+        suite.run_case(self)
+
     def setup(self) -> None:
         self.old_cwd = os.getcwd()
         self.tmpdir = tempfile.TemporaryDirectory(prefix='mypy-test-')
@@ -343,6 +350,22 @@ def teardown(self) -> None:
         self.old_cwd = None
         self.tmpdir = None
 
+    def reportinfo(self) -> Tuple[str, int, str]:
+        return self.file, self.line, self.name
+
+    def repr_failure(self, excinfo: Any) -> str:
+        if excinfo.errisinstance(SystemExit):
+            # We assume that before doing exit() (which raises SystemExit) we've printed
+            # enough context about what happened so that a stack trace is not useful.
+            # In particular, uncaught exceptions during semantic analysis or type checking
+            # call exit() and they already print out a stack trace.
+            excrepr = excinfo.exconly()
+        else:
+            self.parent._prunetraceback(excinfo)
+            excrepr = excinfo.getrepr(style='short')
+
+        return "data: {}:{}:\n{}".format(self.file, self.line, excrepr)
+
     def find_steps(self) -> List[List[FileOperation]]:
         """Return a list of descriptions of file operations for each incremental step.
 
@@ -569,7 +592,7 @@ def fix_cobertura_filename(line: str) -> str:
 
 
 # This function name is special to pytest.  See
-# http://doc.pytest.org/en/latest/writing_plugins.html#initialization-command-line-and-configuration-hooks
+# https://docs.pytest.org/en/latest/reference.html#initialization-hooks
 def pytest_addoption(parser: Any) -> None:
     group = parser.getgroup('mypy')
     group.addoption('--update-data', action='store_true', default=False,
@@ -589,26 +612,20 @@ def pytest_pycollect_makeitem(collector: Any, name: str,
         # Only classes derived from DataSuite contain test cases, not the DataSuite class itself
         if issubclass(obj, DataSuite) and obj is not DataSuite:
             # Non-None result means this obj is a test case.
-            # The collect method of the returned MypyDataSuite instance will be called later,
+            # The collect method of the returned DataSuiteCollector instance will be called later,
             # with self.obj being obj.
-            return MypyDataSuite(name, parent=collector)
+            return DataSuiteCollector(name, parent=collector)
     return None
 
 
-class MypyDataSuite(pytest.Class):  # type: ignore  # inheriting from Any
+class DataSuiteCollector(pytest.Class):  # type: ignore  # inheriting from Any
     def collect(self) -> Iterator[pytest.Item]:  # type: ignore
         """Called by pytest on each of the object returned from pytest_pycollect_makeitem"""
 
         # obj is the object for which pytest_pycollect_makeitem returned self.
         suite = self.obj  # type: DataSuite
         for f in suite.files:
-            for case in parse_test_cases(os.path.join(suite.data_prefix, f),
-                                         base_path=suite.base_path,
-                                         optional_out=suite.optional_out,
-                                         native_sep=suite.native_sep):
-                if suite.filter(case):
-                    case.name = add_test_name_suffix(case.name, suite.test_name_suffix)
-                    yield MypyDataCase(case.name, self, case)
+            yield from parse_test_cases(self, suite, os.path.join(suite.data_prefix, f))
 
 
 def add_test_name_suffix(name: str, suffix: str) -> str:
@@ -637,47 +654,6 @@ def has_stable_flags(testcase: DataDrivenTestCase) -> bool:
     return True
 
 
-class MypyDataCase(pytest.Item):  # type: ignore  # inheriting from Any
-    def __init__(self, name: str, parent: MypyDataSuite, case: DataDrivenTestCase) -> None:
-        self.skip = False
-        if name.endswith('-skip'):
-            self.skip = True
-            name = name[:-len('-skip')]
-
-        super().__init__(name, parent)
-        self.case = case
-
-    def runtest(self) -> None:
-        if self.skip:
-            pytest.skip()
-        suite = self.parent.obj()
-        suite.update_data = self.config.getoption('--update-data', False)
-        suite.setup()
-        suite.run_case(self.case)
-
-    def setup(self) -> None:
-        self.case.setup()
-
-    def teardown(self) -> None:
-        self.case.teardown()
-
-    def reportinfo(self) -> Tuple[str, int, str]:
-        return self.case.file, self.case.line, self.case.name
-
-    def repr_failure(self, excinfo: Any) -> str:
-        if excinfo.errisinstance(SystemExit):
-            # We assume that before doing exit() (which raises SystemExit) we've printed
-            # enough context about what happened so that a stack trace is not useful.
-            # In particular, uncaught exceptions during semantic analysis or type checking
-            # call exit() and they already print out a stack trace.
-            excrepr = excinfo.exconly()
-        else:
-            self.parent._prunetraceback(excinfo)
-            excrepr = excinfo.getrepr(style='short')
-
-        return "data: {}:{}:\n{}".format(self.case.file, self.case.line, excrepr)
-
-
 class DataSuite:
     # option fields - class variables
     files = None  # type: List[str]
@@ -699,7 +675,3 @@ def setup(self) -> None:
     @abstractmethod
     def run_case(self, testcase: DataDrivenTestCase) -> None:
         raise NotImplementedError
-
-    @classmethod
-    def filter(cls, testcase: DataDrivenTestCase) -> bool:
-        return True