aboutsummaryrefslogtreecommitdiff
path: root/readme.md
blob: cec99ef5e6b1d47d1f39bd232ccd6322c8170698 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
# statix

> Lints and suggestions for the Nix programming language.

`statix check` highlights antipatterns in Nix code. `statix
fix` can fix several such occurrences.

For the time-being, `statix` works only with ASTs
produced by the `rnix-parser` crate and does not evaluate
any nix code (imports, attr sets etc.). 

## Examples

```shell
$ statix check tests/c.nix
[W04] Warning: Assignment instead of inherit from
   ╭─[tests/c.nix:2:3]2mtl = pkgs.haskellPackages.mtl;
   ·   ───────────────┬───────────────
   ·                  ╰───────────────── This assignment is better written with inherit
───╯

$ statix fix --dry-run tests/c.nix
--- tests/c.nix
+++ tests/c.nix [fixed]
@@ -1,6 +1,6 @@
 let
-  mtl = pkgs.haskellPackages.mtl;
+  inherit (pkgs.haskellPackages) mtl;
 in
 null
```

## Installation

`statix` is available via a nix flake:

```shell
# build from source
nix build git+https://git.peppe.rs/languages/statix
./result/bin/statix --help

# statix also provides a flake app
nix run git+https://git.peppe.rs/languages/statix -- --help

# save time on builds using cachix
cachix use statix
```

## Usage

Basic usage is as simple as:

```shell
# recursively finds nix files and raises lints
statix check /path/to/dir

# ignore generated files, such as Cargo.nix
statix check /path/to/dir -i Cargo.nix

# ignore more than one file
statix check /path/to/dir -i a.nix b.nix c.nix

# ignore an entire directory
statix check /path/to/dir -i .direnv

# statix respects your .gitignore if it exists
# run statix in "unrestricted" mode, to disable that
statix check /path/to/dir -u

# see `statix -h` for a full list of options
```

Certain lints have suggestions. Apply suggestions back to
the source with:

```shell
statix fix /path/to/file

# show diff, do not write to file
statix fix --dry-run /path/to/file
```

`statix` supports a variety of output formats; standard,
json and errfmt:

```shell
statix check /path/to/dir -o json   # only when compiled with --all-features
statix check /path/to/dir -o errfmt # singleline, easy to integrate with vim
```

## Architecture

`statix` has the following components:

- `bin`: the CLI/entrypoint
- `lib`: library of lints and utilities to define these
  lints
- `vfs`: virtual filesystem
- `macros`: procedural macros to help define a lint

### `bin`

This is the main point of interaction between `statix`
and the end user. It's output is human-readable and should
also support JSON/errorfmt outputs for external tools to
use.

### `lib`

A library of AST-based lints and utilities to help write
those lints. It should be easy for newcomers to write lints
without being familiar with the rest of the codebase.

### `vfs`

VFS is an in-memory filesystem. It provides cheap-to-copy
handles (`FileId`s) to access paths and file contents.

### `macros`

This crate intends to be a helper layer to declare lints and
their metadata.

## TODO

- Test suite for lints and suggestions
- Resolve imports and scopes for better lints
- Add silent flag that exits with status