ch11-24: clean up by @eumiro & sync with Atlas

13-protocol-abc/double/double_object.py

@@ -0,0 +1,2 @@
+def double(x: object) -> object:
+    return x * 2

13-protocol-abc/double/double_protocol.py

@@ -0,0 +1,11 @@
+from typing import TypeVar, Protocol
+
+T = TypeVar('T')  # <1>
+
+class Repeatable(Protocol):
+    def __mul__(self: T, repeat_count: int) -> T: ...  # <2>
+
+RT = TypeVar('RT', bound=Repeatable)  # <3>
+
+def double(x: RT) -> RT:  # <4>
+    return x * 2

13-protocol-abc/double/double_sequence.py

@@ -0,0 +1,6 @@
+from collections import abc
+from typing import Any
+
+def double(x: abc.Sequence) -> Any:
+    return x * 2
+

13-protocol-abc/double/double_test.py

@@ -0,0 +1,56 @@
+from typing import TYPE_CHECKING
+import pytest
+from double_protocol import double
+
+def test_double_int() -> None:
+    given = 2
+    result = double(given)
+    assert result == given * 2
+    if TYPE_CHECKING:
+        reveal_type(given)
+        reveal_type(result)
+
+
+def test_double_str() -> None:
+    given = 'A'
+    result = double(given)
+    assert result == given * 2
+    if TYPE_CHECKING:
+        reveal_type(given)
+        reveal_type(result)
+
+
+def test_double_fraction() -> None:
+    from fractions import Fraction
+    given = Fraction(2, 5)
+    result = double(given)
+    assert result == given * 2
+    if TYPE_CHECKING:
+        reveal_type(given)
+        reveal_type(result)
+
+
+def test_double_array() -> None:
+    from array import array
+    given = array('d', [1.0, 2.0, 3.14])
+    result = double(given)
+    if TYPE_CHECKING:
+        reveal_type(given)
+        reveal_type(result)
+
+
+def test_double_nparray() -> None:
+    import numpy as np  # type: ignore
+    given = np.array([[1, 2], [3, 4]])
+    result = double(given)
+    comparison = result == given * 2
+    assert comparison.all()
+    if TYPE_CHECKING:
+        reveal_type(given)
+        reveal_type(result)
+
+
+def test_double_none() -> None:
+    given = None
+    with pytest.raises(TypeError):
+        result = double(given)