# This file is part of Hypothesis, which may be found at
# https://github.com/HypothesisWorks/hypothesis/
#
# Copyright the Hypothesis Authors.
# Individual contributors are listed in AUTHORS.rst and the git log.
#
# This Source Code Form is subject to the terms of the Mozilla Public License,
# v. 2.0. If a copy of the MPL was not distributed with this file, You can
# obtain one at https://mozilla.org/MPL/2.0/.
"""
.. _hypothesis-cli:
----------------
hypothesis[cli]
----------------
::
$ hypothesis --help
Usage: hypothesis [OPTIONS] COMMAND [ARGS]...
Options:
--version Show the version and exit.
-h, --help Show this message and exit.
Commands:
codemod `hypothesis codemod` refactors deprecated or inefficient code.
fuzz [hypofuzz] runs tests with an adaptive coverage-guided fuzzer.
write `hypothesis write` writes property-based tests for you!
This module requires the :pypi:`click` package, and provides Hypothesis' command-line
interface, for e.g. :doc:`'ghostwriting' tests <ghostwriter>` via the terminal.
It's also where `HypoFuzz <https://hypofuzz.com/>`__ adds the :command:`hypothesis fuzz`
command (`learn more about that here <https://hypofuzz.com/docs/quickstart.html>`__).
"""
import builtins
import importlib
import inspect
import sys
import types
from difflib import get_close_matches
from functools import partial
from multiprocessing import Pool
from pathlib import Path
try:
import pytest
except ImportError:
pytest = None # type: ignore
MESSAGE = """
The Hypothesis command-line interface requires the `{}` package,
which you do not have installed. Run:
python -m pip install --upgrade 'hypothesis[cli]'
and try again.
"""
try:
import click
except ImportError:
def main():
"""If `click` is not installed, tell the user to install it then exit."""
sys.stderr.write(MESSAGE.format("click"))
sys.exit(1)
else:
# Ensure that Python scripts in the current working directory are importable,
# on the principle that Ghostwriter should 'just work' for novice users. Note
# that we append rather than prepend to the module search path, so this will
# never shadow the stdlib or installed packages.
sys.path.append(".")
@click.group(context_settings={"help_option_names": ("-h", "--help")})
@click.version_option()
def main():
pass
def obj_name(s: str) -> object:
"""This "type" imports whatever object is named by a dotted string."""
s = s.strip()
if "/" in s or "\\" in s:
raise click.UsageError(
"Remember that the ghostwriter should be passed the name of a module, not a path."
) from None
try:
return importlib.import_module(s)
except ImportError:
pass
classname = None
if "." not in s:
modulename, module, funcname = "builtins", builtins, s
else:
modulename, funcname = s.rsplit(".", 1)
try:
module = importlib.import_module(modulename)
except ImportError as err:
try:
modulename, classname = modulename.rsplit(".", 1)
module = importlib.import_module(modulename)
except (ImportError, ValueError):
if s.endswith(".py"):
raise click.UsageError(
"Remember that the ghostwriter should be passed the name of a module, not a file."
) from None
raise click.UsageError(
f"Failed to import the {modulename} module for introspection. "
"Check spelling and your Python import path, or use the Python API?"
) from err
def describe_close_matches(
module_or_class: types.ModuleType, objname: str
) -> str:
public_names = [
name for name in vars(module_or_class) if not name.startswith("_")
]
matches = get_close_matches(objname, public_names)
if matches:
return f" Closest matches: {matches!r}"
else:
return ""
if classname is None:
try:
return getattr(module, funcname)
except AttributeError as err:
if funcname == "py":
# Likely attempted to pass a local file (Eg., "myscript.py") instead of a module name
raise click.UsageError(
"Remember that the ghostwriter should be passed the name of a module, not a file."
f"\n\tTry: hypothesis write {s[:-3]}"
) from None
raise click.UsageError(
f"Found the {modulename!r} module, but it doesn't have a "
f"{funcname!r} attribute."
+ describe_close_matches(module, funcname)
) from err
else:
try:
func_class = getattr(module, classname)
except AttributeError as err:
raise click.UsageError(
f"Found the {modulename!r} module, but it doesn't have a "
f"{classname!r} class." + describe_close_matches(module, classname)
) from err
try:
return getattr(func_class, funcname)
except AttributeError as err:
if inspect.isclass(func_class):
func_class_is = "class"
else:
func_class_is = "attribute"
raise click.UsageError(
f"Found the {modulename!r} module and {classname!r} {func_class_is}, "
f"but it doesn't have a {funcname!r} attribute."
+ describe_close_matches(func_class, funcname)
) from err
def _refactor(func, fname):
try:
oldcode = Path(fname).read_text(encoding="utf-8")
except (OSError, UnicodeError) as err:
# Permissions or encoding issue, or file deleted, etc.
return f"skipping {fname!r} due to {err}"
if "hypothesis" not in oldcode:
return # This is a fast way to avoid running slow no-op codemods
try:
newcode = func(oldcode)
except Exception as err:
from libcst import ParserSyntaxError
if isinstance(err, ParserSyntaxError):
from hypothesis.extra._patching import indent
msg = indent(str(err).replace("\n\n", "\n"), " ").strip()
return f"skipping {fname!r} due to {msg}"
raise
if newcode != oldcode:
Path(fname).write_text(newcode, encoding="utf-8")
@main.command() # type: ignore # Click adds the .command attribute
@click.argument("path", type=str, required=True, nargs=-1)
def codemod(path):
"""`hypothesis codemod` refactors deprecated or inefficient code.
It adapts `python -m libcst.tool`, removing many features and config options
which are rarely relevant for this purpose. If you need more control, we
encourage you to use the libcst CLI directly; if not this one is easier.
PATH is the file(s) or directories of files to format in place, or
"-" to read from stdin and write to stdout.
"""
try:
from libcst.codemod import gather_files
from hypothesis.extra import codemods
except ImportError:
sys.stderr.write(
"You are missing required dependencies for this option. Run:\n\n"
" python -m pip install --upgrade hypothesis[codemods]\n\n"
"and try again."
)
sys.exit(1)
# Special case for stdin/stdout usage
if "-" in path:
if len(path) > 1:
raise Exception(
"Cannot specify multiple paths when reading from stdin!"
)
print("Codemodding from stdin", file=sys.stderr)
print(codemods.refactor(sys.stdin.read()))
return 0
# Find all the files to refactor, and then codemod them
files = gather_files(path)
errors = set()
if len(files) <= 1:
errors.add(_refactor(codemods.refactor, *files))
else:
with Pool() as pool:
for msg in pool.imap_unordered(
partial(_refactor, codemods.refactor), files
):
errors.add(msg)
errors.discard(None)
for msg in errors:
print(msg, file=sys.stderr)
return 1 if errors else 0
@main.command() # type: ignore # Click adds the .command attribute
@click.argument("func", type=obj_name, required=True, nargs=-1)
@click.option(
"--roundtrip",
"writer",
flag_value="roundtrip",
help="start by testing write/read or encode/decode!",
)
@click.option(
"--equivalent",
"writer",
flag_value="equivalent",
help="very useful when optimising or refactoring code",
)
@click.option(
"--errors-equivalent",
"writer",
flag_value="errors-equivalent",
help="--equivalent, but also allows consistent errors",
)
@click.option(
"--idempotent",
"writer",
flag_value="idempotent",
help="check that f(x) == f(f(x))",
)
@click.option(
"--binary-op",
"writer",
flag_value="binary_operation",
help="associativity, commutativity, identity element",
)
# Note: we deliberately omit a --ufunc flag, because the magic()
# detection of ufuncs is both precise and complete.
@click.option(
"--style",
type=click.Choice(["pytest", "unittest"]),
default="pytest" if pytest else "unittest",
help="pytest-style function, or unittest-style method?",
)
@click.option(
"-e",
"--except",
"except_",
type=obj_name,
multiple=True,
help="dotted name of exception(s) to ignore",
)
@click.option(
"--annotate/--no-annotate",
default=None,
help="force ghostwritten tests to be type-annotated (or not). "
"By default, match the code to test.",
)
def write(func, writer, except_, style, annotate): # \b disables autowrap
"""`hypothesis write` writes property-based tests for you!
Type annotations are helpful but not required for our advanced introspection
and templating logic. Try running the examples below to see how it works:
\b
hypothesis write gzip
hypothesis write numpy.matmul
hypothesis write pandas.from_dummies
hypothesis write re.compile --except re.error
hypothesis write --equivalent ast.literal_eval eval
hypothesis write --roundtrip json.dumps json.loads
hypothesis write --style=unittest --idempotent sorted
hypothesis write --binary-op operator.add
"""
# NOTE: if you want to call this function from Python, look instead at the
# ``hypothesis.extra.ghostwriter`` module. Click-decorated functions have
# a different calling convention, and raise SystemExit instead of returning.
kwargs = {"except_": except_ or (), "style": style, "annotate": annotate}
if writer is None:
writer = "magic"
elif writer == "idempotent" and len(func) > 1:
raise click.UsageError("Test functions for idempotence one at a time.")
elif writer == "roundtrip" and len(func) == 1:
writer = "idempotent"
elif "equivalent" in writer and len(func) == 1:
writer = "fuzz"
if writer == "errors-equivalent":
writer = "equivalent"
kwargs["allow_same_errors"] = True
try:
from hypothesis.extra import ghostwriter
except ImportError:
sys.stderr.write(MESSAGE.format("black"))
sys.exit(1)
code = getattr(ghostwriter, writer)(*func, **kwargs)
try:
from rich.console import Console
from rich.syntax import Syntax
from hypothesis.utils.terminal import guess_background_color
except ImportError:
print(code)
else:
try:
theme = "default" if guess_background_color() == "light" else "monokai"
code = Syntax(code, "python", background_color="default", theme=theme)
Console().print(code, soft_wrap=True)
except Exception:
print("# Error while syntax-highlighting code", file=sys.stderr)
print(code)