pyicontract-lint 2.1.4

Description:

pyicontractlint 2.1.4

pyicontract-lint





pyicontract-lint lints contracts in Python code defined with
icontract library.
The following checks are performed:


Description
Identifier



File should be read and decoded correctly.
unreadable

A preconditions expects a subset of function’s arguments.
pre-invalid-arg

A snapshot expects at most an argument element of the function’s arguments.
snapshot-invalid-arg

If a snapshot is defined on a function, a postcondition must be defined as well.
snapshot-wo-post

A capture function must be defined in the contract.
snapshot-wo-capture

A postcondition expects a subset of function’s arguments.
post-invalid-arg

If a function returns None, a postcondition should not expect result as argument.
post-result-none

If a postcondition expects result argument, the function should not expect it.
post-result-conflict

If a postcondition expects OLD argument, the function should not expect it.
post-old-conflict

An invariant should only expect self argument.
inv-invalid-arg

A condition must be defined in the contract.
no-condition

File must be valid Python code.
invalid-syntax





Usage
Pyicontract-lint parses the code and tries to infer the imported modules and functions using
astroid library. Hence you need to make sure that imported modules are on your
PYTHONPATH before you invoke pyicontract-lint.
Once you set up the environment, invoke pyicontract-lint with a list of positional arguments as paths:
pyicontract-lint \
/path/to/some/directory/some-file.py \
/path/to/some/directory/another-file.py
You can also invoke it on directories. Pyicontract-lint will recursively search for *.py files (including the
subdirectories) and verify the files:
pyicontract-lint \
/path/to/some/directory
By default, pyicontract-lint outputs the errors in a verbose, human-readable format. If you prefer JSON, supply it
--format argument:
pyicontract-lint \
--format json \
/path/to/some/directory
If one or more checks fail, the return code will be non-zero. You can specify --dont_panic argument if you want
to have a zero return code even though one or more checks failed:
pyicontract-lint \
--dont_panic \
/path/to/some/directory
To disable any pyicontract-lint checks on a file, add # pyicontract-lint: disabled on a separate line to the file.
This is useful when you recursively lint files in a directory and want to exclude certain files.

Module icontract_lint
The API is provided in the icontract_lint module if you want to use pycontract-lint programmatically.
The main points of entry in icontract_line module are:

check_file(...): lint a single file,
check_recursively(...): lint a directory and
check_paths(...): lint files and directories.

The output is produced by functions output_verbose(...) and output_json(...).
Here is an example code that lints a list of given paths and produces a verbose output:
import pathlib
import sys

import icontract_lint

errors = icontract_lint.check_paths(paths=[
pathlib.Path('/some/directory/file.py'),
pathlib.Path('/yet/yet/another/directory'),
pathlib.Path('/another/directory/another_file.py'),
pathlib.Path('/yet/another/directory'),
])

output_verbose(errors=errors, stream=sys.stdout)
The full documentation of the module is available on
readthedocs.



Installation

Install pyicontract-lint with pip:

pip3 install pyicontract-lint


Development

Check out the repository.
In the repository root, create the virtual environment:

python3 -m venv venv3

Activate the virtual environment:

source venv3/bin/activate

Install the development dependencies:

pip3 install -e .[dev]

We use tox for testing and packaging the distribution. Run:

tox

We also provide a set of pre-commit checks that lint and check code for formatting. Run them locally from an activated
virtual environment with development dependencies:

./precommit.py

The pre-commit script can also automatically format the code:

./precommit.py --overwrite


Versioning
We follow Semantic Versioning. The version X.Y.Z indicates:

X is the major version (backward-incompatible),
Y is the minor version (backward-compatible), and
Z is the patch version (backward-compatible bug fix).