https://github.com/uber/neal

🔎🐞 A language-agnostic linting platform
https://github.com/uber/neal

ocaml python swift uber

Last synced: about 8 hours ago
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🔎🐞 A language-agnostic linting platform

• Host: GitHub
• URL: https://github.com/uber/neal
• Owner: uber
• License: mit
• Created: 2017-08-14T19:41:49.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2022-04-15T19:02:53.000Z (over 2 years ago)
• Last Synced: 2024-09-24T23:09:47.170Z (about 12 hours ago)
• Topics: ocaml, python, swift, uber
• Language: OCaml
• Homepage: https://uber.github.io/NEAL/
• Size: 1.76 MB
• Stars: 429
• Watchers: 15
• Forks: 28
• Open Issues: 12
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE

Awesome Lists containing this project

README

        
NEAL

====

**NEAL** (**N**\ ot **E**\ xactly **A** **L**\ inter) is a language-independent code analysis tool that aims to enable more people to write quality enforcement rules.

Example

-------

One of the simplest rules we have at Uber is to restrict the use of `Forced-Values in Swift`__. (`This post`__ explains some of the risks of abusing forced-values.)

__ https://docs.swift.org/swift-book/ReferenceManual/Expressions.html#ID404

__ https://www.andrewcbancroft.com/2016/06/13/force-unwrapping-swift-optionals-code-smell/

A forced-value consists of any expression that results in an optional value followed by the forced-unwrapping operator (``!``). Here's a contrived example that would result in a runtime crash.

.. code-block:: swift

  // test.swift

  (nil as Int?)!

NEAL doesn't have any rules built-in, so we have to write a new rule to detect this pattern:

.. code-block:: cpp

  // test.rules

  rule NoForcedValues {

    Swift::ForcedValueExpression {

      fail("No forced unwrapping allowed")

    }

  }

Now if you run NEAL you should see something like the following:

.. code-block:: bash

  $ neal --rules test.rules test.swift

  [1 of 1]: Analysing test.swift

  On file test.swift: (NoForcedValues)

    1 | (nil as Int?)!

    ~ |              ^

  error: No forced unwrapping allowed

Alternatively, you can create a minimal configuration file called ``neal.json``:

.. code-block:: json

  {

    "rules": [ "test.rules" ]

  }

After that you can get the same result by simply running:

.. code-block:: bash

  $ neal .

For a more comprehensive guide to writing your own rules check out `Writing a new rule `_.

Installation

------------

The recommended way of installing NEAL is through `Homebrew `_, using the following command:

.. code-block:: bash

  $ brew install neal

Installing from source

++++++++++++++++++++++

To build and install NEAL from source, make sure you have `OPAM`__ installed and that you're using OCaml 4.13.1 or later.

.. code-block:: bash

  $ brew install opam

  $ opam init

  $ opam switch 4.13.1

  $ eval "$(opam config env)"

__ https://opam.ocaml.org/

After you have setup OPAM and OCaml, you can setup, build and install NEAL using ``make``.

.. code-block:: bash

  $ NATIVE=1 make setup build install

Basic usage

-----------

NEAL has builtin support for Python and Swift, but it's highly extensible, and can be used with any language.

.. code-block:: bash

  $ neal [options] [path to files or directories]

For a list of CLI options, runtime options and configuration attributes see the `Configuration `_ guide.

Acknowledgements

----------------

- OCaml CI Scripts (https://github.com/ocaml/ocaml-ci-scripts)

.. _brew: https://brew.sh

.. toctree::

  :hidden:

  :titlesonly:

  Getting Started 

  rules

  testing_rules

  reference

  configuration

  basics

  components/index.rst

  developing

  changelog