implemented pytest for makepyfile

tests/test_makepyfile.py

@@ -0,0 +1,262 @@
+from encodings.aliases import aliases
+from pathlib import Path
+from textwrap import dedent
+from typing import Tuple
+
+import pytest
+
+pytest_plugins = ["pytester"]
+
+
+def enc(enc):
+    try:
+        _ = "abc".encode(enc)
+    except Exception:
+        return False
+
+    return True
+
+
+all_encodings = set(filter(enc, aliases.values()))
+
+
+@pytest.fixture(params=all_encodings)
+def encoding(request):
+    return request.param
+
+
+# UTF-8 Fixture (contains various Unicode characters)
+@pytest.fixture(
+    params=[
+        ("3", "4"),
+        ("☆", "★"),
+        ("1", "☀"),
+        ("✅", "💥"),
+    ],
+    ids=[
+        "numbers",
+        "stars",
+        "number-sun",
+        "check-explosion",
+    ],
+)
+def utf8_charset(request):
+    return request.param
+
+
+# CP-1252 Fixture (contains characters from Windows-1252 encoding)
+@pytest.fixture(
+    params=[
+        ("é", "ü"),
+        ("„", "“"),
+        ("¥", "ƒ"),
+        ("©", "®"),
+    ],
+    ids=[
+        "accented_letters_CP1252",
+        "quotes_CP1252",
+        "currency_symbols_CP1252",
+        "copyright_registered_CP1252",
+    ],
+)
+def cp1252_charset(request):
+    return request.param
+
+
+# ANSI (Strictly ASCII characters only)
+@pytest.fixture(
+    params=[
+        ("A", "B"),
+        ("1", "2"),
+        ("!", "?"),
+        ("@", "#"),
+    ],
+    ids=[
+        "letters_ANSI",
+        "numbers_ANSI",
+        "punctuation_ANSI",
+        "symbols_ANSI",
+    ],
+)
+def ansi_charset(request):
+    return request.param
+
+
+@pytest.fixture(
+    params=[
+        ("3", "4"),
+        ("A", "B"),
+        ("!", "?"),
+        ("☆", "☁"),
+        ("✅", "💥"),
+        ("é", "ü"),
+        ("Я", "ж"),  # Cyrillic characters
+        ("Ф", "Щ"),  # More Cyrillic
+        ("中", "国"),  # Chinese characters (zhong guo - China)
+        ("道", "德"),  # Chinese characters (dao de - way virtue)
+    ],
+    ids=[
+        "numbers",
+        "letters",
+        "punctuation",
+        "stars",
+        "check-explosion",
+        "accented_letters",
+        "cyrillic_basic",
+        "cyrillic_complex",
+        "chinese_country",
+        "chinese_concept",
+    ],
+)
+def any_charset(request):
+    return request.param
+
+
+@pytest.fixture
+def makepyfile_encoded(testdir, encoding, any_charset):
+    a, b = any_charset
+
+    original_file = testdir.makepyfile(
+        f"""
+        def f():
+            '''
+            >>> print({a})
+            {b}
+            '''
+            pass
+        """,
+        encoding=encoding,
+    )
+
+    expected_diff = dedent(
+        f"""
+            >>> print({a})
+        -   {b}
+        +   {a}
+        """
+    )
+
+    yield original_file, expected_diff, encoding
+
+
+def makebasicfile(tmp_path: Path, a, b, encoding: str) -> Tuple[Path, str]:
+    """alternative implementation without the use of `testdir.makepyfile`."""
+
+    original_file = Path(tmp_path).joinpath("test_basic.py")
+    code = dedent(
+        f"""
+        def f():
+            '''
+            >>> print({a})
+            {b}
+            '''
+            pass
+        """
+    )
+
+    original_file.write_text(code, encoding=encoding)
+
+    expected_diff = dedent(
+        f"""
+            >>> print({a})
+        -   {b}
+        +   {a}
+        """
+    )
+
+    return original_file, expected_diff
+
+
+@pytest.fixture
+def basic_encoded(tmp_path, encoding, any_charset):
+
+    a, b = any_charset
+
+    file, diff = makebasicfile(tmp_path, a, b, encoding)
+
+    yield file, diff, encoding
+
+
+@pytest.mark.xfail(reason="UnicodeDecodeError")
+def test_makepyfile(makepyfile_encoded):
+    """
+    Test is expected to fail because of UnicodeDecodeError.
+
+    Just to compare visually with `test_basicfile` to see the difference
+    """
+
+    file, diff, enc = makepyfile_encoded
+
+    text = Path(file).read_text(enc)
+
+    print(text, diff)
+
+
+@pytest.mark.xfail(reason="UnicodeDecodeError")
+def test_basicfile(basic_encoded):
+    """
+    Test is expected to fail because of UnicodeDecodeError.
+
+    Just to compare visually with `test_makepyfile` to see the difference
+    """
+    file, diff, enc = basic_encoded
+
+    text = Path(file).read_text(enc)
+
+    print(text, diff)
+
+
+def test_compare_make_basic_file(testdir, encoding, any_charset):
+    """
+    Compare testdir.makepyfile with pathlib.Path.writetext to create python files.
+
+    Expected behavior is when `testdir.makepyfile` created a file with given encoding,
+    `makebasicfile` also should be able to encode the charset.
+
+    If a UnicodeEncodeError is raised, it means `testdir.makepyfile` screwed up the
+    encoding.
+    """
+
+    a, b = any_charset
+
+    # create a python file with testdir.makepyfile in the old fashioned way
+
+    make_file = testdir.makepyfile(
+        f"""
+        def f():
+            '''
+            >>> print({a})
+            {b}
+            '''
+            pass
+        """,
+        encoding=encoding,
+    )
+
+    assert Path(
+        make_file
+    ).is_file(), f"`testdir.makepyfile` failed encode {repr((a,b))} with {encoding=}"
+
+    make_diff = dedent(
+        f"""
+            >>> print({a})
+        -   {b}
+        +   {a}
+        """
+    )
+
+    # try to check if makepyfile screwed up and create python file in a different way
+
+    try:
+        basic_file, basic_diff = makebasicfile(str(testdir), a, b, encoding)
+    except UnicodeEncodeError:
+        pytest.fail(
+            f"testdir.makepyfile encoding {repr((a,b))} with {encoding=}, but it sould have failed."
+        )
+
+    assert Path(
+        basic_file
+    ).is_file(), f"`makebasicfile` failed encode {repr((a,b))} with {encoding=}"
+    assert (
+        make_diff == basic_diff
+    ), "sanity check - diffs always should be the same, if not my test implementation is wrong."