1 # Basics for hacking on Clippy
3 This document explains the basics for hacking on Clippy. Besides others, this
4 includes how to build and test Clippy. For a more in depth description on
5 the codebase take a look at [Adding Lints] or [Common Tools].
7 [Adding Lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
8 [Common Tools]: https://github.com/rust-lang/rust-clippy/blob/master/doc/common_tools_writing_lints.md
10 - [Basics for hacking on Clippy](#basics-for-hacking-on-clippy)
11 - [Get the Code](#get-the-code)
12 - [Building and Testing](#building-and-testing)
13 - [`cargo dev`](#cargo-dev)
18 First, make sure you have checked out the latest version of Clippy. If this is
19 your first time working on Clippy, create a fork of the repository and clone it
20 afterwards with the following command:
23 git clone git@github.com:<your-username>/rust-clippy
26 If you've already cloned Clippy in the past, update it to the latest version:
29 # upstream has to be the remote of the rust-lang/rust-clippy repo
31 # make sure that you are on the master branch
33 # rebase your master branch on the upstream master
34 git rebase upstream/master
35 # push to the master branch of your fork
39 ## Building and Testing
41 You can build and test Clippy like every other Rust project:
44 cargo build # builds Clippy
45 cargo test # tests Clippy
48 Since Clippy's test suite is pretty big, there are some commands that only run a
49 subset of Clippy's tests:
54 # only run UI tests starting with `test_`
55 TESTNAME="test_" cargo uitest
56 # only run dogfood tests
57 cargo test --test dogfood
60 If the output of a [UI test] differs from the expected output, you can update the
67 For example, this is necessary, if you fix a typo in an error message of a lint
68 or if you modify a test file to add a test case.
70 _Note:_ This command may update more files than you intended. In that case only
71 commit the files you wanted to update.
73 [UI test]: https://rustc-dev-guide.rust-lang.org/tests/adding.html#guide-to-the-ui-tests
77 Clippy has some dev tools to make working on Clippy more convenient. These tools
78 can be accessed through the `cargo dev` command. Available tools are listed
79 below. To get more information about these commands, just call them with
83 # formats the whole Clippy codebase and all tests
85 # register or update lint names/groups/...
86 cargo dev update_lints
87 # create a new lint and register it
89 # (experimental) Setup Clippy to work with rust-analyzer
95 We follow a rustc no merge-commit policy.
96 See <https://rustc-dev-guide.rust-lang.org/contributing.html#opening-a-pr>.