Fix download badge link (#3853)

[etc/vim.git] / tests / util.py

diff --git a/tests/util.py b/tests/util.py
index 9c3d3cbc99d031e2a1d6cc556bd0b4ca0af878c0..967d576fafe7e23caf99be31f9af8ec3eab35dc7 100644 (file)
--- a/tests/util.py
+++ b/tests/util.py
@@ -1,34 +1,179 @@
+import os
+import sys

 import unittest
 from contextlib import contextmanager
 import unittest
 from contextlib import contextmanager

+from dataclasses import replace
+from functools import partial

 from pathlib import Path
 from pathlib import Path

-from typing import List, Tuple, Iterator
+from typing import Any, Iterator, List, Optional, Tuple
+
+import black
+from black.debug import DebugVisitor
+from black.mode import TargetVersion
+from black.output import diff, err, out
+
+PYTHON_SUFFIX = ".py"
+ALLOWED_SUFFIXES = (PYTHON_SUFFIX, ".pyi", ".out", ".diff", ".ipynb")

 
 THIS_DIR = Path(__file__).parent
 
 THIS_DIR = Path(__file__).parent

+DATA_DIR = THIS_DIR / "data"

 PROJECT_ROOT = THIS_DIR.parent
 EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
 DETERMINISTIC_HEADER = "[Deterministic header]"
 
 PROJECT_ROOT = THIS_DIR.parent
 EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
 DETERMINISTIC_HEADER = "[Deterministic header]"
 

+PY36_VERSIONS = {
+    TargetVersion.PY36,
+    TargetVersion.PY37,
+    TargetVersion.PY38,
+    TargetVersion.PY39,
+}

 
 

-@contextmanager
-def skip_if_exception(e: str) -> Iterator[None]:
+DEFAULT_MODE = black.Mode()
+ff = partial(black.format_file_in_place, mode=DEFAULT_MODE, fast=True)
+fs = partial(black.format_str, mode=DEFAULT_MODE)
+
+
+def _assert_format_equal(expected: str, actual: str) -> None:
+    if actual != expected and not os.environ.get("SKIP_AST_PRINT"):
+        bdv: DebugVisitor[Any]
+        out("Expected tree:", fg="green")
+        try:
+            exp_node = black.lib2to3_parse(expected)
+            bdv = DebugVisitor()
+            list(bdv.visit(exp_node))
+        except Exception as ve:
+            err(str(ve))
+        out("Actual tree:", fg="red")
+        try:
+            exp_node = black.lib2to3_parse(actual)
+            bdv = DebugVisitor()
+            list(bdv.visit(exp_node))
+        except Exception as ve:
+            err(str(ve))
+
+    if actual != expected:
+        out(diff(expected, actual, "expected", "actual"))
+
+    assert actual == expected
+
+
+class FormatFailure(Exception):
+    """Used to wrap failures when assert_format() runs in an extra mode."""
+
+
+def assert_format(
+    source: str,
+    expected: str,
+    mode: black.Mode = DEFAULT_MODE,
+    *,
+    fast: bool = False,
+    minimum_version: Optional[Tuple[int, int]] = None,
+) -> None:
+    """Convenience function to check that Black formats as expected.
+
+    You can pass @minimum_version if you're passing code with newer syntax to guard
+    safety guards so they don't just crash with a SyntaxError. Please note this is
+    separate from TargetVerson Mode configuration.
+    """
+    _assert_format_inner(
+        source, expected, mode, fast=fast, minimum_version=minimum_version
+    )
+
+    # For both preview and non-preview tests, ensure that Black doesn't crash on
+    # this code, but don't pass "expected" because the precise output may differ.

     try:
     try:

-        yield
-    except Exception as exc:
-        if exc.__class__.__name__ == e:
-            unittest.skip(f"Encountered expected exception {exc}, skipping")
-        else:
-            raise
+        _assert_format_inner(
+            source,
+            None,
+            replace(mode, preview=not mode.preview),
+            fast=fast,
+            minimum_version=minimum_version,
+        )
+    except Exception as e:
+        text = "non-preview" if mode.preview else "preview"
+        raise FormatFailure(
+            f"Black crashed formatting this case in {text} mode."
+        ) from e
+    # Similarly, setting line length to 1 is a good way to catch
+    # stability bugs. But only in non-preview mode because preview mode
+    # currently has a lot of line length 1 bugs.
+    try:
+        _assert_format_inner(
+            source,
+            None,
+            replace(mode, preview=False, line_length=1),
+            fast=fast,
+            minimum_version=minimum_version,
+        )
+    except Exception as e:
+        raise FormatFailure(
+            "Black crashed formatting this case with line-length set to 1."
+        ) from e
+
+
+def _assert_format_inner(
+    source: str,
+    expected: Optional[str] = None,
+    mode: black.Mode = DEFAULT_MODE,
+    *,
+    fast: bool = False,
+    minimum_version: Optional[Tuple[int, int]] = None,
+) -> None:
+    actual = black.format_str(source, mode=mode)
+    if expected is not None:
+        _assert_format_equal(expected, actual)
+    # It's not useful to run safety checks if we're expecting no changes anyway. The
+    # assertion right above will raise if reality does actually make changes. This just
+    # avoids wasted CPU cycles.
+    if not fast and source != actual:
+        # Unfortunately the AST equivalence check relies on the built-in ast module
+        # being able to parse the code being formatted. This doesn't always work out
+        # when checking modern code on older versions.
+        if minimum_version is None or sys.version_info >= minimum_version:
+            black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, mode=mode)
+
+
+def dump_to_stderr(*output: str) -> str:
+    return "\n" + "\n".join(output) + "\n"
+

 
 

+class BlackBaseTestCase(unittest.TestCase):
+    def assertFormatEqual(self, expected: str, actual: str) -> None:
+        _assert_format_equal(expected, actual)

 
 

-def read_data(name: str, data: bool = True) -> Tuple[str, str]:
+
+def get_base_dir(data: bool) -> Path:
+    return DATA_DIR if data else PROJECT_ROOT
+
+
+def all_data_cases(subdir_name: str, data: bool = True) -> List[str]:
+    cases_dir = get_base_dir(data) / subdir_name
+    assert cases_dir.is_dir()
+    return [case_path.stem for case_path in cases_dir.iterdir()]
+
+
+def get_case_path(
+    subdir_name: str, name: str, data: bool = True, suffix: str = PYTHON_SUFFIX
+) -> Path:
+    """Get case path from name"""
+    case_path = get_base_dir(data) / subdir_name / name
+    if not name.endswith(ALLOWED_SUFFIXES):
+        case_path = case_path.with_suffix(suffix)
+    assert case_path.is_file(), f"{case_path} is not a file."
+    return case_path
+
+
+def read_data(subdir_name: str, name: str, data: bool = True) -> Tuple[str, str]:

     """read_data('test_name') -> 'input', 'output'"""
     """read_data('test_name') -> 'input', 'output'"""

-    if not name.endswith((".py", ".pyi", ".out", ".diff")):
-        name += ".py"
+    return read_data_from_file(get_case_path(subdir_name, name, data))
+
+
+def read_data_from_file(file_name: Path) -> Tuple[str, str]:
+    with open(file_name, "r", encoding="utf8") as test:
+        lines = test.readlines()

     _input: List[str] = []
     _output: List[str] = []
     _input: List[str] = []
     _output: List[str] = []

-    base_dir = THIS_DIR / "data" if data else PROJECT_ROOT
-    with open(base_dir / name, "r", encoding="utf8") as test:
-        lines = test.readlines()

     result = _input
     for line in lines:
         line = line.replace(EMPTY_LINE, "")
     result = _input
     for line in lines:
         line = line.replace(EMPTY_LINE, "")


@@ -41,3 +186,26 @@ def read_data(name: str, data: bool = True) -> Tuple[str, str]:
         # If there's no output marker, treat the entire file as already pre-formatted.
         _output = _input[:]
     return "".join(_input).strip() + "\n", "".join(_output).strip() + "\n"
         # If there's no output marker, treat the entire file as already pre-formatted.
         _output = _input[:]
     return "".join(_input).strip() + "\n", "".join(_output).strip() + "\n"

+
+
+def read_jupyter_notebook(subdir_name: str, name: str, data: bool = True) -> str:
+    return read_jupyter_notebook_from_file(
+        get_case_path(subdir_name, name, data, suffix=".ipynb")
+    )
+
+
+def read_jupyter_notebook_from_file(file_name: Path) -> str:
+    with open(file_name, mode="rb") as fd:
+        content_bytes = fd.read()
+    return content_bytes.decode()
+
+
+@contextmanager
+def change_directory(path: Path) -> Iterator[None]:
+    """Context manager to temporarily chdir to a different directory."""
+    previous_dir = os.getcwd()
+    try:
+        os.chdir(path)
+        yield
+    finally:
+        os.chdir(previous_dir)