Source code for hypothesis.extra.codemods

# This file is part of Hypothesis, which may be found at
# Most of this work is copyright (C) 2013-2021 David R. MacIver
# (, but it contains contributions by others. See
# CONTRIBUTING.rst for a full list of people who may hold copyright, and
# consult the git log if you need to determine who owns an individual
# contribution.
# 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

.. _codemods:


This module provides codemods based on the :pypi:`LibCST` library, which can
both detect *and automatically fix* issues with code that uses Hypothesis,
including upgrading from deprecated features to our recommended style.

You can run the codemods via our CLI::

    $ hypothesis codemod --help
    Usage: hypothesis codemod [OPTIONS] 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.

      -h, --help  Show this message and exit.

Alternatively you can use ``python -m libcst.tool``, which offers more control
at the cost of additional configuration (adding ``'hypothesis.extra'`` to the
``modules`` list in ``.libcst.codemod.yaml``) and `some issues on Windows

.. autofunction:: refactor

import importlib
from inspect import Parameter, signature
from typing import List

import libcst as cst
import libcst.matchers as m
from libcst.codemod import VisitorBasedCodemodCommand

[docs]def refactor(code: str) -> str: """Update a source code string from deprecated to modern Hypothesis APIs. This may not fix *all* the deprecation warnings in your code, but we're confident that it will be easier than doing it all by hand. We recommend using the CLI, but if you want a Python function here it is. """ context = cst.codemod.CodemodContext() mod = cst.parse_module(code) transforms: List[VisitorBasedCodemodCommand] = [ HypothesisFixPositionalKeywonlyArgs(context), HypothesisFixComplexMinMagnitude(context), ] for transform in transforms: mod = transform.transform_module(mod) return mod.code
def match_qualname(name): # We use the metadata to get qualname instead of matching directly on function # name, because this handles some scope and "from x import y as z" issues. return m.MatchMetadataIfTrue( cst.metadata.QualifiedNameProvider, # If there are multiple possible qualnames, e.g. due to conditional imports, # be conservative. Better to leave the user to fix a few things by hand than # to break their code while attempting to refactor it! lambda qualnames: all( == name for n in qualnames), ) class HypothesisFixComplexMinMagnitude(VisitorBasedCodemodCommand): """Fix a deprecated min_magnitude=None argument for complex numbers:: st.complex_numbers(min_magnitude=None) -> st.complex_numbers(min_magnitude=0) Note that this should be run *after* ``HypothesisFixPositionalKeywonlyArgs``, in order to handle ``st.complex_numbers(None)``. """ DESCRIPTION = "Fix a deprecated min_magnitude=None argument for complex numbers." METADATA_DEPENDENCIES = (cst.metadata.QualifiedNameProvider,) @m.call_if_inside( m.Call(metadata=match_qualname("hypothesis.strategies.complex_numbers")) ) def leave_Arg(self, original_node, updated_node): if m.matches( updated_node, m.Arg(keyword=m.Name("min_magnitude"), value=m.Name("None")) ): return updated_node.with_changes(value=cst.Integer("0")) return updated_node class HypothesisFixPositionalKeywonlyArgs(VisitorBasedCodemodCommand): """Fix positional arguments for newly keyword-only parameters, e.g.:: st.fractions(0, 1, 9) -> st.fractions(0, 1, max_denominator=9) Applies to a majority of our public API, since keyword-only parameters are great but we couldn't use them until after we dropped support for Python 2. """ DESCRIPTION = "Fix positional arguments for newly keyword-only parameters." METADATA_DEPENDENCIES = (cst.metadata.QualifiedNameProvider,) kwonly_functions = ( "", "hypothesis.find", "hypothesis.extra.lark.from_lark", "hypothesis.extra.numpy.arrays", "hypothesis.extra.numpy.array_shapes", "hypothesis.extra.numpy.unsigned_integer_dtypes", "hypothesis.extra.numpy.integer_dtypes", "hypothesis.extra.numpy.floating_dtypes", "hypothesis.extra.numpy.complex_number_dtypes", "hypothesis.extra.numpy.datetime64_dtypes", "hypothesis.extra.numpy.timedelta64_dtypes", "hypothesis.extra.numpy.byte_string_dtypes", "hypothesis.extra.numpy.unicode_string_dtypes", "hypothesis.extra.numpy.array_dtypes", "hypothesis.extra.numpy.nested_dtypes", "hypothesis.extra.numpy.valid_tuple_axes", "hypothesis.extra.numpy.broadcastable_shapes", "hypothesis.extra.pandas.indexes", "hypothesis.extra.pandas.series", "hypothesis.extra.pandas.columns", "hypothesis.extra.pandas.data_frames", "", "hypothesis.stateful.run_state_machine_as_test", "hypothesis.stateful.rule", "hypothesis.stateful.initialize", "hypothesis.strategies.floats", "hypothesis.strategies.lists", "hypothesis.strategies.sets", "hypothesis.strategies.frozensets", "hypothesis.strategies.iterables", "hypothesis.strategies.dictionaries", "hypothesis.strategies.characters", "hypothesis.strategies.text", "hypothesis.strategies.from_regex", "hypothesis.strategies.binary", "hypothesis.strategies.fractions", "hypothesis.strategies.decimals", "hypothesis.strategies.recursive", "hypothesis.strategies.complex_numbers", "hypothesis.strategies.shared", "hypothesis.strategies.uuids", "hypothesis.strategies.runner", "hypothesis.strategies.functions", "hypothesis.strategies.datetimes", "hypothesis.strategies.times", ) def leave_Call(self, original_node, updated_node): """Convert positional to keyword arguments.""" metadata = self.get_metadata(cst.metadata.QualifiedNameProvider, original_node) qualnames = { for qn in metadata} # If this isn't one of our known functions, or it has no posargs, stop there. if ( len(qualnames) != 1 or not qualnames.intersection(self.kwonly_functions) or not m.matches( updated_node, m.Call( func=m.DoesNotMatch(m.Call()), args=[m.Arg(keyword=None), m.ZeroOrMore()], ), ) ): return updated_node # Get the actual function object so that we can inspect the signature. # This does e.g. incur a dependency on Numpy to fix Numpy-dependent code, # but having a single source of truth about the signatures is worth it. mod, fn = list(qualnames.intersection(self.kwonly_functions))[0].rsplit(".", 1) try: func = getattr(importlib.import_module(mod), fn) except ImportError: return updated_node # Create new arg nodes with the newly required keywords assign_nospace = cst.AssignEqual( whitespace_before=cst.SimpleWhitespace(""), whitespace_after=cst.SimpleWhitespace(""), ) newargs = [ arg if arg.keyword or or p.kind is not Parameter.KEYWORD_ONLY else arg.with_changes(keyword=cst.Name(, equal=assign_nospace) for p, arg in zip(signature(func).parameters.values(), updated_node.args) ] return updated_node.with_changes(args=newargs)