Convention for test data which uses APIs defined by Python stubs

CONTRIBUTING.md

@@ -14,6 +14,8 @@ are important to the project's success.
     * [Contact us](#discussion) before starting significant work.
     * IMPORTANT: For new libraries, [get permission from the library owner first](#adding-a-new-library).
     * Create your stubs [conforming to the coding style](#stub-file-coding-style).
+    * Add tests for your stubs to `test_data`. These tests are not meant
+      to be executable. Type checkers analyze them statically.
     * Make sure `runtests.sh` passes cleanly on Mypy, pytype, and flake8.
 4. [Submit your changes](#submitting-changes):
     * Open a pull request

stdlib/2/typing.pyi

@@ -355,8 +355,17 @@ def cast(tp: Type[_T], obj: Any) -> _T: ...
 
 # Type constructors
 
-# NamedTuple is special-cased in the type checker; the initializer is ignored.
-def NamedTuple(typename: str, fields: Iterable[Tuple[str, Any]], *,
-               verbose: bool = ..., rename: bool = ...) -> Type[tuple]: ...
+# NamedTuple is special-cased in the type checker
+class NamedTuple(tuple):
+    _fields = ...  # type: Tuple[str, ...]
+
+    def __init__(self, typename: str, fields: Iterable[Tuple[str, Any]], *,
+                 verbose: bool = ..., rename: bool = ...) -> None: ...
+
+    @classmethod
+    def _make(cls, iterable: Iterable[Any]) -> NamedTuple: ...
+
+    def _asdict(self) -> dict: ...
+    def _replace(self, **kwargs: Any) -> NamedTuple: ...
 
 def NewType(name: str, tp: Type[_T]) -> Type[_T]: ...

stdlib/3/typing.pyi

@@ -462,8 +462,17 @@ def cast(tp: Type[_T], obj: Any) -> _T: ...
 
 # Type constructors
 
-# NamedTuple is special-cased in the type checker; the initializer is ignored.
-def NamedTuple(typename: str, fields: Iterable[Tuple[str, Any]], *,
-               verbose: bool = ..., rename: bool = ..., module: str = None) -> Type[tuple]: ...
+# NamedTuple is special-cased in the type checker
+class NamedTuple(tuple):
+    _fields = ...  # type: Tuple[str, ...]
+
+    def __init__(self, typename: str, fields: Iterable[Tuple[str, Any]], *,
+                 verbose: bool = ..., rename: bool = ..., module: Any = ...) -> None: ...
+
+    @classmethod
+    def _make(cls, iterable: Iterable[Any]) -> NamedTuple: ...
+
+    def _asdict(self) -> dict: ...
+    def _replace(self, **kwargs: Any) -> NamedTuple: ...
 
 def NewType(name: str, tp: Type[_T]) -> Type[_T]: ...

test_data/stdlib/2and3/collections_test.py

@@ -0,0 +1,14 @@
+from collections import namedtuple
+
+
+def test_collections_namedtuple():
+    # type: () -> None
+    Point = namedtuple('Point', 'x y')
+    p = Point(1, 2)
+
+    p._replace(y=3.14)
+    p._asdict()
+    p.x, p.y
+    p[0] + p[1]
+    p.index(1)
+    Point._make([('x', 1), ('y', 3.14)])

test_data/stdlib/2and3/typing_test.py

@@ -0,0 +1,14 @@
+from typing import NamedTuple
+
+
+def test_typing_namedtuple():
+    # type: () -> None
+    Point = NamedTuple('Point', [('x', float), ('y', float)])
+    p = Point(1, 2)
+
+    p._replace(y=3.14)
+    p._asdict()
+    p.x, p.y
+    p[0] + p[1]
+    p.index(1)
+    Point._make([('x', 1), ('y', 3.14)])

test_data/stdlib/3.6/typing_test.py

@@ -0,0 +1,16 @@
+from typing import NamedTuple
+
+
+class Point(NamedTuple):
+    x: float
+    y: float
+
+
+def test_typing_namedtuple():
+    # type: () -> None
+    p = Point(1, 2)
+    p._asdict()
+    p.x, p.y
+    p[0] + p[1]
+    p.index(1)
+    Point._make([('x', 1), ('y', 3.14)])

tests/mypy_test.py

@@ -63,7 +63,7 @@ def libpath(major, minor):
     versions.append('2and3')
     paths = []
     for v in versions:
-        for top in ['stdlib', 'third_party']:
+        for top in ['stdlib', 'third_party', 'test_data/stdlib', 'test_data/third_party']:
             p = os.path.join(top, v)
             if os.path.isdir(p):
                 paths.append(p)

tests/pytype_test.py

@@ -70,7 +70,7 @@ def pytype_test(args):
         print("Cannot run pytd. Did you install pytype?")
         return 0, 0
 
-    wanted = re.compile(r"stdlib/(2|2\.7|2and3)/.*\.pyi$")
+    wanted = re.compile(r"stdlib/(2|2\.7|2and3)/.*\.pyi?$")
     skipped = re.compile("(%s)$" % "|".join(load_blacklist()))
     files = []
 
@@ -80,6 +80,15 @@ def pytype_test(args):
             if wanted.search(f) and not skipped.search(f):
                 files.append(f)
 
+    # XXX: Temporarily disabled checking test_data/ due to a bug
+    # in pytype related to handling type hints in function comments
+
+    # for root, _, filenames in os.walk("test_data/stdlib"):
+    #     for f in sorted(filenames):
+    #         f = os.path.join(root, f)
+    #         if wanted.search(f) and not skipped.search(f):
+    #             files.append(f)
+
     running_tests = collections.deque()
     max_code, runs, errors = 0, 0, 0
     print("Running pytype tests...")