Merge pull request #7862 from asottile/comm2ann

py36+: com2ann

Author: asottile

.pre-commit-config.yaml

@@ -44,6 +44,10 @@ repos:
     -   id: setup-cfg-fmt
         # TODO: when upgrading setup-cfg-fmt this can be removed
         args: [--max-py-version=3.9]
+-   repo: https://github.com/pre-commit/pygrep-hooks
+    rev: v1.6.0
+    hooks:
+    -   id: python-use-type-annotations
 -   repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.782  # NOTE: keep this in sync with setup.cfg.
     hooks:

src/_pytest/_argcomplete.py

@@ -103,7 +103,7 @@ def __call__(self, prefix: str, **kwargs: Any) -> List[str]:
         import argcomplete.completers
     except ImportError:
         sys.exit(-1)
-    filescompleter = FastFilesCompleter()  # type: Optional[FastFilesCompleter]
+    filescompleter: Optional[FastFilesCompleter] = FastFilesCompleter()
 
     def try_argcomplete(parser: argparse.ArgumentParser) -> None:
         argcomplete.autocomplete(parser, always_complete_options=False)

src/_pytest/_code/code.py

@@ -164,7 +164,7 @@ def getargs(self, var: bool = False):
 class TracebackEntry:
     """A single entry in a Traceback."""
 
-    _repr_style = None  # type: Optional[Literal["short", "long"]]
+    _repr_style: Optional['Literal["short", "long"]'] = None
     exprinfo = None
 
     def __init__(
@@ -246,9 +246,9 @@ def ishidden(self) -> bool:
 
         Mostly for internal use.
         """
-        tbh = (
+        tbh: Union[bool, Callable[[Optional[ExceptionInfo[BaseException]]], bool]] = (
             False
-        )  # type: Union[bool, Callable[[Optional[ExceptionInfo[BaseException]]], bool]]
+        )
         for maybe_ns_dct in (self.frame.f_locals, self.frame.f_globals):
             # in normal cases, f_locals and f_globals are dictionaries
             # however via `exec(...)` / `eval(...)` they can be other types
@@ -301,7 +301,7 @@ def __init__(
         if isinstance(tb, TracebackType):
 
             def f(cur: TracebackType) -> Iterable[TracebackEntry]:
-                cur_ = cur  # type: Optional[TracebackType]
+                cur_: Optional[TracebackType] = cur
                 while cur_ is not None:
                     yield TracebackEntry(cur_, excinfo=excinfo)
                     cur_ = cur_.tb_next
@@ -381,7 +381,7 @@ def getcrashentry(self) -> TracebackEntry:
     def recursionindex(self) -> Optional[int]:
         """Return the index of the frame/TracebackEntry where recursion originates if
         appropriate, None if no recursion occurred."""
-        cache = {}  # type: Dict[Tuple[Any, int, int], List[Dict[str, Any]]]
+        cache: Dict[Tuple[Any, int, int], List[Dict[str, Any]]] = {}
         for i, entry in enumerate(self):
             # id for the code.raw is needed to work around
             # the strange metaprogramming in the decorator lib from pypi
@@ -760,7 +760,7 @@ def repr_traceback_entry(
         entry: TracebackEntry,
         excinfo: Optional[ExceptionInfo[BaseException]] = None,
     ) -> "ReprEntry":
-        lines = []  # type: List[str]
+        lines: List[str] = []
         style = entry._repr_style if entry._repr_style is not None else self.style
         if style in ("short", "long"):
             source = self._getentrysource(entry)
@@ -842,7 +842,7 @@ def _truncate_recursive_traceback(
             recursionindex = traceback.recursionindex()
         except Exception as e:
             max_frames = 10
-            extraline = (
+            extraline: Optional[str] = (
                 "!!! Recursion error detected, but an error occurred locating the origin of recursion.\n"
                 "  The following exception happened when comparing locals in the stack frame:\n"
                 "    {exc_type}: {exc_msg}\n"
@@ -852,7 +852,7 @@ def _truncate_recursive_traceback(
                 exc_msg=str(e),
                 max_frames=max_frames,
                 total=len(traceback),
-            )  # type: Optional[str]
+            )
             # Type ignored because adding two instaces of a List subtype
             # currently incorrectly has type List instead of the subtype.
             traceback = traceback[:max_frames] + traceback[-max_frames:]  # type: ignore
@@ -868,20 +868,20 @@ def _truncate_recursive_traceback(
     def repr_excinfo(
         self, excinfo: ExceptionInfo[BaseException]
     ) -> "ExceptionChainRepr":
-        repr_chain = (
-            []
-        )  # type: List[Tuple[ReprTraceback, Optional[ReprFileLocation], Optional[str]]]
-        e = excinfo.value  # type: Optional[BaseException]
-        excinfo_ = excinfo  # type: Optional[ExceptionInfo[BaseException]]
+        repr_chain: List[
+            Tuple[ReprTraceback, Optional[ReprFileLocation], Optional[str]]
+        ] = []
+        e: Optional[BaseException] = excinfo.value
+        excinfo_: Optional[ExceptionInfo[BaseException]] = excinfo
         descr = None
-        seen = set()  # type: Set[int]
+        seen: Set[int] = set()
         while e is not None and id(e) not in seen:
             seen.add(id(e))
             if excinfo_:
                 reprtraceback = self.repr_traceback(excinfo_)
-                reprcrash = (
+                reprcrash: Optional[ReprFileLocation] = (
                     excinfo_._getreprcrash() if self.style != "value" else None
-                )  # type: Optional[ReprFileLocation]
+                )
             else:
                 # Fallback to native repr if the exception doesn't have a traceback:
                 # ExceptionInfo objects require a full traceback to work.
@@ -936,11 +936,11 @@ def toterminal(self, tw: TerminalWriter) -> None:
 @attr.s(eq=False)
 class ExceptionRepr(TerminalRepr):
     # Provided by subclasses.
-    reprcrash = None  # type: Optional[ReprFileLocation]
-    reprtraceback = None  # type: ReprTraceback
+    reprcrash: Optional["ReprFileLocation"]
+    reprtraceback: "ReprTraceback"
 
     def __attrs_post_init__(self) -> None:
-        self.sections = []  # type: List[Tuple[str, str, str]]
+        self.sections: List[Tuple[str, str, str]] = []
 
     def addsection(self, name: str, content: str, sep: str = "-") -> None:
         self.sections.append((name, content, sep))
@@ -1022,7 +1022,7 @@ def __init__(self, tblines: Sequence[str]) -> None:
 @attr.s(eq=False)
 class ReprEntryNative(TerminalRepr):
     lines = attr.ib(type=Sequence[str])
-    style = "native"  # type: _TracebackStyle
+    style: "_TracebackStyle" = "native"
 
     def toterminal(self, tw: TerminalWriter) -> None:
         tw.write("".join(self.lines))
@@ -1058,9 +1058,9 @@ def _write_entry_lines(self, tw: TerminalWriter) -> None:
         # such as ">   assert 0"
         fail_marker = f"{FormattedExcinfo.fail_marker}   "
         indent_size = len(fail_marker)
-        indents = []  # type: List[str]
-        source_lines = []  # type: List[str]
-        failure_lines = []  # type: List[str]
+        indents: List[str] = []
+        source_lines: List[str] = []
+        failure_lines: List[str] = []
         for index, line in enumerate(self.lines):
             is_failure_line = line.startswith(fail_marker)
             if is_failure_line:

src/_pytest/_code/source.py

@@ -21,7 +21,7 @@ class Source:
 
     def __init__(self, obj: object = None) -> None:
         if not obj:
-            self.lines = []  # type: List[str]
+            self.lines: List[str] = []
         elif isinstance(obj, Source):
             self.lines = obj.lines
         elif isinstance(obj, (tuple, list)):
@@ -144,12 +144,12 @@ def deindent(lines: Iterable[str]) -> List[str]:
 def get_statement_startend2(lineno: int, node: ast.AST) -> Tuple[int, Optional[int]]:
     # Flatten all statements and except handlers into one lineno-list.
     # AST's line numbers start indexing at 1.
-    values = []  # type: List[int]
+    values: List[int] = []
     for x in ast.walk(node):
         if isinstance(x, (ast.stmt, ast.ExceptHandler)):
             values.append(x.lineno - 1)
             for name in ("finalbody", "orelse"):
-                val = getattr(x, name, None)  # type: Optional[List[ast.stmt]]
+                val: Optional[List[ast.stmt]] = getattr(x, name, None)
                 if val:
                     # Treat the finally/orelse part as its own statement.
                     values.append(val[0].lineno - 1 - 1)

src/_pytest/_io/terminalwriter.py

@@ -76,7 +76,7 @@ def __init__(self, file: Optional[TextIO] = None) -> None:
         self._file = file
         self.hasmarkup = should_do_markup(file)
         self._current_line = ""
-        self._terminal_width = None  # type: Optional[int]
+        self._terminal_width: Optional[int] = None
         self.code_highlight = True
 
     @property
@@ -204,7 +204,7 @@ def _highlight(self, source: str) -> str:
         except ImportError:
             return source
         else:
-            highlighted = highlight(
+            highlighted: str = highlight(
                 source, PythonLexer(), TerminalFormatter(bg="dark")
-            )  # type: str
+            )
             return highlighted

src/_pytest/assertion/__init__.py

@@ -83,7 +83,7 @@ class AssertionState:
     def __init__(self, config: Config, mode) -> None:
         self.mode = mode
         self.trace = config.trace.root.get("assertion")
-        self.hook = None  # type: Optional[rewrite.AssertionRewritingHook]
+        self.hook: Optional[rewrite.AssertionRewritingHook] = None
 
 
 def install_importhook(config: Config) -> rewrite.AssertionRewritingHook:

src/_pytest/assertion/rewrite.py

@@ -62,14 +62,14 @@ def __init__(self, config: Config) -> None:
             self.fnpats = config.getini("python_files")
         except ValueError:
             self.fnpats = ["test_*.py", "*_test.py"]
-        self.session = None  # type: Optional[Session]
-        self._rewritten_names = set()  # type: Set[str]
-        self._must_rewrite = set()  # type: Set[str]
+        self.session: Optional[Session] = None
+        self._rewritten_names: Set[str] = set()
+        self._must_rewrite: Set[str] = set()
         # flag to guard against trying to rewrite a pyc file while we are already writing another pyc file,
         # which might result in infinite recursion (#3506)
         self._writing_pyc = False
         self._basenames_to_check_rewrite = {"conftest"}
-        self._marked_for_rewrite_cache = {}  # type: Dict[str, bool]
+        self._marked_for_rewrite_cache: Dict[str, bool] = {}
         self._session_paths_checked = False
 
     def set_session(self, session: Optional[Session]) -> None:
@@ -529,12 +529,12 @@ def _fix(node, lineno, col_offset):
 
 def _get_assertion_exprs(src: bytes) -> Dict[int, str]:
     """Return a mapping from {lineno: "assertion test expression"}."""
-    ret = {}  # type: Dict[int, str]
+    ret: Dict[int, str] = {}
 
     depth = 0
-    lines = []  # type: List[str]
-    assert_lineno = None  # type: Optional[int]
-    seen_lines = set()  # type: Set[int]
+    lines: List[str] = []
+    assert_lineno: Optional[int] = None
+    seen_lines: Set[int] = set()
 
     def _write_and_reset() -> None:
         nonlocal depth, lines, assert_lineno, seen_lines
@@ -699,12 +699,12 @@ def run(self, mod: ast.Module) -> None:
         ]
         mod.body[pos:pos] = imports
         # Collect asserts.
-        nodes = [mod]  # type: List[ast.AST]
+        nodes: List[ast.AST] = [mod]
         while nodes:
             node = nodes.pop()
             for name, field in ast.iter_fields(node):
                 if isinstance(field, list):
-                    new = []  # type: List[ast.AST]
+                    new: List[ast.AST] = []
                     for i, child in enumerate(field):
                         if isinstance(child, ast.Assert):
                             # Transform assert.
@@ -776,7 +776,7 @@ def push_format_context(self) -> None:
         to format a string of %-formatted values as added by
         .explanation_param().
         """
-        self.explanation_specifiers = {}  # type: Dict[str, ast.expr]
+        self.explanation_specifiers: Dict[str, ast.expr] = {}
         self.stack.append(self.explanation_specifiers)
 
     def pop_format_context(self, expl_expr: ast.expr) -> ast.Name:
@@ -828,15 +828,15 @@ def visit_Assert(self, assert_: ast.Assert) -> List[ast.stmt]:
                 lineno=assert_.lineno,
             )
 
-        self.statements = []  # type: List[ast.stmt]
-        self.variables = []  # type: List[str]
+        self.statements: List[ast.stmt] = []
+        self.variables: List[str] = []
         self.variable_counter = itertools.count()
 
         if self.enable_assertion_pass_hook:
-            self.format_variables = []  # type: List[str]
+            self.format_variables: List[str] = []
 
-        self.stack = []  # type: List[Dict[str, ast.expr]]
-        self.expl_stmts = []  # type: List[ast.stmt]
+        self.stack: List[Dict[str, ast.expr]] = []
+        self.expl_stmts: List[ast.stmt] = []
         self.push_format_context()
         # Rewrite assert into a bunch of statements.
         top_condition, explanation = self.visit(assert_.test)
@@ -943,7 +943,7 @@ def visit_BoolOp(self, boolop: ast.BoolOp) -> Tuple[ast.Name, str]:
         # Process each operand, short-circuiting if needed.
         for i, v in enumerate(boolop.values):
             if i:
-                fail_inner = []  # type: List[ast.stmt]
+                fail_inner: List[ast.stmt] = []
                 # cond is set in a prior loop iteration below
                 self.expl_stmts.append(ast.If(cond, fail_inner, []))  # noqa
                 self.expl_stmts = fail_inner
@@ -954,10 +954,10 @@ def visit_BoolOp(self, boolop: ast.BoolOp) -> Tuple[ast.Name, str]:
             call = ast.Call(app, [expl_format], [])
             self.expl_stmts.append(ast.Expr(call))
             if i < levels:
-                cond = res  # type: ast.expr
+                cond: ast.expr = res
                 if is_or:
                     cond = ast.UnaryOp(ast.Not(), cond)
-                inner = []  # type: List[ast.stmt]
+                inner: List[ast.stmt] = []
                 self.statements.append(ast.If(cond, inner, []))
                 self.statements = body = inner
         self.statements = save
@@ -1053,7 +1053,7 @@ def visit_Compare(self, comp: ast.Compare) -> Tuple[ast.expr, str]:
             ast.Tuple(results, ast.Load()),
         )
         if len(comp.ops) > 1:
-            res = ast.BoolOp(ast.And(), load_names)  # type: ast.expr
+            res: ast.expr = ast.BoolOp(ast.And(), load_names)
         else:
             res = load_names[0]
         return res, self.explanation_param(self.pop_format_context(expl_call))

src/_pytest/assertion/util.py

@@ -21,11 +21,11 @@
 # interpretation code and assertion rewriter to detect this plugin was
 # loaded and in turn call the hooks defined here as part of the
 # DebugInterpreter.
-_reprcompare = None  # type: Optional[Callable[[str, object, object], Optional[str]]]
+_reprcompare: Optional[Callable[[str, object, object], Optional[str]]] = None
 
 # Works similarly as _reprcompare attribute. Is populated with the hook call
 # when pytest_runtest_setup is called.
-_assertion_pass = None  # type: Optional[Callable[[int, str, str], None]]
+_assertion_pass: Optional[Callable[[int, str, str], None]] = None
 
 
 def format_explanation(explanation: str) -> str:
@@ -197,7 +197,7 @@ def _diff_text(left: str, right: str, verbose: int = 0) -> List[str]:
     """
     from difflib import ndiff
 
-    explanation = []  # type: List[str]
+    explanation: List[str] = []
 
     if verbose < 1:
         i = 0  # just in case left or right has zero length
@@ -242,7 +242,7 @@ def _compare_eq_verbose(left: Any, right: Any) -> List[str]:
     left_lines = repr(left).splitlines(keepends)
     right_lines = repr(right).splitlines(keepends)
 
-    explanation = []  # type: List[str]
+    explanation: List[str] = []
     explanation += ["+" + line for line in left_lines]
     explanation += ["-" + line for line in right_lines]
 
@@ -296,7 +296,7 @@ def _compare_eq_sequence(
     left: Sequence[Any], right: Sequence[Any], verbose: int = 0
 ) -> List[str]:
     comparing_bytes = isinstance(left, bytes) and isinstance(right, bytes)
-    explanation = []  # type: List[str]
+    explanation: List[str] = []
     len_left = len(left)
     len_right = len(right)
     for i in range(min(len_left, len_right)):
@@ -365,7 +365,7 @@ def _compare_eq_set(
 def _compare_eq_dict(
     left: Mapping[Any, Any], right: Mapping[Any, Any], verbose: int = 0
 ) -> List[str]:
-    explanation = []  # type: List[str]
+    explanation: List[str] = []
     set_left = set(left)
     set_right = set(right)
     common = set_left.intersection(set_right)