add rustfmt fixer

7 files changed, 76 insertions, 2 deletions

diff --git a/README.md b/README.md
index 120177ed..df5ba225 100644
--- a/README.md
+++ b/README.md
@@ -127,7 +127,7 @@ formatting.
 | reStructuredText | [proselint](http://proselint.com/) |
 | RPM spec | [rpmlint](https://github.com/rpm-software-management/rpmlint) (disabled by default; see `:help ale-integration-spec`) |
 | Ruby | [brakeman](http://brakemanscanner.org/) !!, [rails_best_practices](https://github.com/flyerhzm/rails_best_practices) !!, [reek](https://github.com/troessner/reek), [rubocop](https://github.com/bbatsov/rubocop), [ruby](https://www.ruby-lang.org) |
-| Rust |  cargo !! (see `:help ale-integration-rust` for configuration instructions), [rls](https://github.com/rust-lang-nursery/rls), [rustc](https://www.rust-lang.org/) |
+| Rust |  cargo !! (see `:help ale-integration-rust` for configuration instructions), [rls](https://github.com/rust-lang-nursery/rls), [rustc](https://www.rust-lang.org/), [rustfmt](https://github.com/rust-lang-nursery/rustfmt) |
 | SASS | [sass-lint](https://www.npmjs.com/package/sass-lint), [stylelint](https://github.com/stylelint/stylelint) |
 | SCSS | [sass-lint](https://www.npmjs.com/package/sass-lint), [scss-lint](https://github.com/brigade/scss-lint), [stylelint](https://github.com/stylelint/stylelint), [prettier](https://github.com/prettier/prettier) |
 | Scala | [scalac](http://scala-lang.org), [scalastyle](http://www.scalastyle.org) |
diff --git a/autoload/ale/fix/registry.vim b/autoload/ale/fix/registry.vim
index d26c71ab..07daa402 100644
--- a/autoload/ale/fix/registry.vim
+++ b/autoload/ale/fix/registry.vim
@@ -107,6 +107,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['typescript'],
 \       'description': 'Fix typescript files with tslint --fix.',
 \   },
+\   'rustfmt': {
+\       'function': 'ale#fixers#rustfmt#Fix',
+\       'suggested_filetypes': ['rust'],
+\       'description': 'Fix Rust files with Rustfmt.',
+\   },
 \}
 
 " Reset the function registry to the default entries.
diff --git a/autoload/ale/fixers/rustfmt.vim b/autoload/ale/fixers/rustfmt.vim
new file mode 100644
index 00000000..fb5ac61c
--- /dev/null
+++ b/autoload/ale/fixers/rustfmt.vim
@@ -0,0 +1,17 @@
+" Author: Kelly Fox <kelly@bumfuddled.com>
+" Description: Integration of rustfmt with ALE.
+
+call ale#Set('rust_rustfmt_executable', 'rustfmt')
+call ale#Set('rust_rustfmt_options', '')
+
+function! ale#fixers#rustfmt#Fix(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'rust_rustfmt_executable')
+    let l:options = ale#Var(a:buffer, 'rust_rustfmt_options')
+
+    return {
+    \   'command': ale#Escape(l:executable)
+    \       . (empty(l:options) ? '' : ' ' . l:options)
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction
diff --git a/doc/ale-rust.txt b/doc/ale-rust.txt
index 52dc3d61..e20aea2c 100644
--- a/doc/ale-rust.txt
+++ b/doc/ale-rust.txt
@@ -22,6 +22,8 @@ Integration Information
      over cargo. rls implements the Language Server Protocol for incremental
      compilation of Rust code, and can check Rust files while you type. `rls`
      requires Rust files to contained in Cargo projects.
+  4. rustfmt -- If you have `rustfmt` installed, you can use it as a fixer to
+     consistently reformat your Rust code.
 
   Only cargo is enabled by default. To switch to using rustc instead of cargo,
   configure |g:ale_linters| appropriately: >
@@ -71,4 +73,15 @@ g:ale_rust_ignore_error_codes                   *g:ale_rust_ignore_error_codes*
 
 
 ===============================================================================
+rustfmt                                                      *ale-rust-rustfmt*
+
+g:ale_rust_rustfmt_options                         *g:ale_rust_rustfmt_options*
+                                                   *b:ale_rust_rustfmt_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be set to pass additional options to the rustfmt fixer.
+
+
+===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
diff --git a/doc/ale.txt b/doc/ale.txt
index fb0b5a76..acf64289 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -142,6 +142,7 @@ CONTENTS                                                         *ale-contents*
       cargo...............................|ale-rust-cargo|
       rls.................................|ale-rust-rls|
       rustc...............................|ale-rust-rustc|
+      rustfmt.............................|ale-rust-rustfmt|
     sass..................................|ale-sass-options|
       stylelint...........................|ale-sass-stylelint|
     scala.................................|ale-scala-options|
@@ -280,7 +281,7 @@ Notes:
 * reStructuredText: `proselint`
 * RPM spec: `rpmlint`
 * Ruby: `brakeman`, `rails_best_practices`!!, `reek`, `rubocop`, `ruby`
-* Rust: `cargo`!!, `rls`, `rustc` (see |ale-integration-rust|)
+* Rust: `cargo`!!, `rls`, `rustc` (see |ale-integration-rust|), `rustfmt`
 * SASS: `sass-lint`, `stylelint`
 * SCSS: `sass-lint`, `scss-lint`, `stylelint`, `prettier`
 * Scala: `scalac`, `scalastyle`
diff --git a/test/fixers/test_rustfmt_fixer_callback.vader b/test/fixers/test_rustfmt_fixer_callback.vader
new file mode 100644
index 00000000..36dd58a1
--- /dev/null
+++ b/test/fixers/test_rustfmt_fixer_callback.vader
@@ -0,0 +1,38 @@
+Before:
+  Save g:ale_rust_rustfmt_executable
+  Save g:ale_rust_rustfmt_options
+
+  " Use an invalid global executable, so we don't match it.
+  let g:ale_rust_rustfmt_executable = 'xxxinvalid'
+  let g:ale_rust_rustfmt_options = ''
+
+  call ale#test#SetDirectory('/testplugin/test/fixers')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+
+Execute(The rustfmt callback should return the correct default values):
+  call ale#test#SetFilename('../rust_files/testfile.rs')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape('xxxinvalid')
+  \     . ' %t',
+  \ },
+  \ ale#fixers#rustfmt#Fix(bufnr(''))
+
+Execute(The rustfmt callback should include custom rustfmt options):
+  let g:ale_rust_rustfmt_options = "--skip-children"
+  call ale#test#SetFilename('../rust_files/testfile.rs')
+
+  AssertEqual
+  \ {
+  \   'read_temporary_file': 1,
+  \   'command': ale#Escape('xxxinvalid')
+  \     . ' ' . g:ale_rust_rustfmt_options
+  \     . ' %t',
+  \ },
+  \ ale#fixers#rustfmt#Fix(bufnr(''))
diff --git a/test/rust_files/testfile.rs b/test/rust_files/testfile.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/test/rust_files/testfile.rs