Add support for rust-analyzer

Fixes #2832

5 files changed, 70 insertions, 0 deletions

diff --git a/ale_linters/rust/analyzer.vim b/ale_linters/rust/analyzer.vim
new file mode 100644
index 00000000..54a7cb1c
--- /dev/null
+++ b/ale_linters/rust/analyzer.vim
@@ -0,0 +1,24 @@
+" Author: Jon Gjengset <jon@thesquareplanet.com>
+" Description: The next generation language server for Rust
+
+call ale#Set('rust_analyzer_executable', 'ra_lsp_server')
+call ale#Set('rust_analyzer_config', {})
+
+function! ale_linters#rust#analyzer#GetCommand(buffer) abort
+    return '%e'
+endfunction
+
+function! ale_linters#rust#analyzer#GetProjectRoot(buffer) abort
+    let l:cargo_file = ale#path#FindNearestFile(a:buffer, 'Cargo.toml')
+
+    return !empty(l:cargo_file) ? fnamemodify(l:cargo_file, ':h') : ''
+endfunction
+
+call ale#linter#Define('rust', {
+\   'name': 'rust-analyzer',
+\   'lsp': 'stdio',
+\   'lsp_config': {b -> ale#Var(b, 'rust_analyzer_config')},
+\   'executable': {b -> ale#Var(b, 'rust_analyzer_executable')},
+\   'command': function('ale_linters#rust#analyzer#GetCommand'),
+\   'project_root': function('ale_linters#rust#analyzer#GetProjectRoot'),
+\})
diff --git a/doc/ale-rust.txt b/doc/ale-rust.txt
index 44a79b18..05390225 100644
--- a/doc/ale-rust.txt
+++ b/doc/ale-rust.txt
@@ -23,6 +23,11 @@ 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.
+  3. analyzer -- If you have rust-analyzer installed, you might prefer using
+     this linter over cargo and rls. rust-analyzer also implements the
+     Language Server Protocol for incremental compilation of Rust code, and is
+     the next iteration of rls. rust-analyzer, like 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.
 
@@ -191,6 +196,25 @@ g:ale_rust_rls_config                                   *g:ale_rust_rls_config*
 
 
 ===============================================================================
+analyzer                                                    *ale-rust-analyzer*
+
+g:ale_rust_analyzer_executable                 *g:ale_rust_analyzer_executable*
+                                               *b:ale_rust_analyzer_executable*
+  Type: |String|
+  Default: `'ra_lsp_server'`
+
+  This variable can be modified to change the executable path for
+  `rust-analyzer`.
+
+
+g:ale_rust_analyzer_config                         *g:ale_rust_analyzer_config*
+                                                   *b:ale_rust_analyzer_config*
+  Type: |Dictionary|
+  Default: `{}`
+
+  Dictionary with configuration settings for rust-analyzer.
+
+===============================================================================
 rustc                                                          *ale-rust-rustc*
 
 
diff --git a/doc/ale.txt b/doc/ale.txt
index 01b6181d..e8716de1 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -2411,6 +2411,7 @@ documented in additional help files.
   rust....................................|ale-rust-options|
     cargo.................................|ale-rust-cargo|
     rls...................................|ale-rust-rls|
+    rust-analyzer.........................|ale-rust-analyzer|
     rustc.................................|ale-rust-rustc|
     rustfmt...............................|ale-rust-rustfmt|
   sass....................................|ale-sass-options|
diff --git a/supported-tools.md b/supported-tools.md
index 226baeaf..90dd719f 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -413,6 +413,7 @@ formatting.
 * Rust
   * [cargo](https://github.com/rust-lang/cargo) :floppy_disk: (see `:help ale-integration-rust` for configuration instructions)
   * [rls](https://github.com/rust-lang-nursery/rls) :warning:
+  * [rust-analyzer](https://github.com/rust-analyzer/rust-analyzer) :warning:
   * [rustc](https://www.rust-lang.org/) :warning:
   * [rustfmt](https://github.com/rust-lang-nursery/rustfmt)
 * Sass
diff --git a/test/command_callback/test_rust_analyzer_callbacks.vader b/test/command_callback/test_rust_analyzer_callbacks.vader
new file mode 100644
index 00000000..887cf127
--- /dev/null
+++ b/test/command_callback/test_rust_analyzer_callbacks.vader
@@ -0,0 +1,20 @@
+Before:
+  call ale#assert#SetUpLinterTest('rust', 'analyzer')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(The default executable path should be correct):
+  AssertLinter 'analyzer', ale#Escape('ra_lsp_server')
+
+Execute(The project root should be detected correctly):
+  AssertLSPProject ''
+
+  call ale#test#SetFilename('rust-rls-project/test.rs')
+
+  AssertLSPProject ale#path#Simplify(g:dir . '/rust-rls-project')
+
+Execute(Should accept configuration settings):
+  AssertLSPConfig {}
+  let b:ale_rust_analyzer_config = {'rust': {'clippy_preference': 'on'}}
+  AssertLSPConfig {'rust': {'clippy_preference': 'on'}}