Add yaml-language-server support for YAML (#2874) (#4029)

7 files changed, 111 insertions, 0 deletions

diff --git a/ale_linters/yaml/ls.vim b/ale_linters/yaml/ls.vim
new file mode 100644
index 00000000..8e3f6d00
--- /dev/null
+++ b/ale_linters/yaml/ls.vim
@@ -0,0 +1,34 @@
+" Author: Jeffrey Lau - https://github.com/zoonfafer
+" Description: YAML Language Server https://github.com/redhat-developer/yaml-language-server
+
+call ale#Set('yaml_ls_executable', 'yaml-language-server')
+call ale#Set('yaml_ls_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('yaml_ls_config', {})
+
+function! ale_linters#yaml#ls#GetExecutable(buffer) abort
+    return ale#path#FindExecutable(a:buffer, 'yaml_ls', [
+    \   'node_modules/.bin/yaml-language-server',
+    \])
+endfunction
+
+function! ale_linters#yaml#ls#GetCommand(buffer) abort
+    let l:executable = ale_linters#yaml#ls#GetExecutable(a:buffer)
+
+    return ale#Escape(l:executable) . ' --stdio'
+endfunction
+
+" Just use the current file
+function! ale_linters#yaml#ls#FindProjectRoot(buffer) abort
+    let l:project_file = expand('#' . a:buffer . ':p')
+
+    return fnamemodify(l:project_file, ':h')
+endfunction
+
+call ale#linter#Define('yaml', {
+\   'name': 'yaml-language-server',
+\   'lsp': 'stdio',
+\   'executable': function('ale_linters#yaml#ls#GetExecutable'),
+\   'command': function('ale_linters#yaml#ls#GetCommand'),
+\   'project_root': function('ale_linters#yaml#ls#FindProjectRoot'),
+\   'lsp_config': {b -> ale#Var(b, 'yaml_ls_config')},
+\})
diff --git a/doc/ale-supported-languages-and-tools.txt b/doc/ale-supported-languages-and-tools.txt
index f93e0807..ed1d1d5e 100644
--- a/doc/ale-supported-languages-and-tools.txt
+++ b/doc/ale-supported-languages-and-tools.txt
@@ -640,6 +640,7 @@ Notes:
   * `prettier`
   * `spectral`
   * `swaglint`
+  * `yaml-language-server`
   * `yamlfix`
   * `yamllint`
 * YANG
diff --git a/doc/ale-yaml.txt b/doc/ale-yaml.txt
index 65e0d069..a5da85a5 100644
--- a/doc/ale-yaml.txt
+++ b/doc/ale-yaml.txt
@@ -106,6 +106,59 @@ g:ale_yaml_swaglint_use_global                 *g:ale_yaml_swaglint_use_global*
 
 
 ===============================================================================
+yaml-language-server                                 *ale-yaml-language-server*
+
+Website: https://github.com/redhat-developer/yaml-language-server
+
+
+Installation
+-------------------------------------------------------------------------------
+
+Install yaml-language-server either globally or locally: >
+
+  npm install yaml-language-server -g  # global
+  npm install yaml-language-server     # local
+
+
+Options
+-------------------------------------------------------------------------------
+
+g:ale_yaml_ls_executable                             *g:ale_yaml_ls_executable*
+                                                     *b:ale_yaml_ls_executable*
+  Type: |String|
+  Default: `'yaml-language-server'`
+
+  This variable can be set to change the path to yaml-language-server.
+
+
+g:ale_yaml_ls_config                                     *g:ale_yaml_ls_config*
+                                                         *b:ale_yaml_ls_config*
+  Type: |Dictionary|
+  Default: `{}`
+
+  Dictionary containing configuration settings that will be passed to the
+  language server.  For example, to enable schema store: >
+      {
+    \   'yaml': {
+    \     'schemaStore': {
+    \         'enable': v:true,
+    \     },
+    \   },
+    \ }
+<
+  Consult the yaml-language-server documentation for more information about
+  settings.
+
+
+g:ale_yaml_ls_use_global                             *g:ale_yaml_ls_use_global*
+                                                     *b:ale_yaml_ls_use_global*
+  Type: |String|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
+===============================================================================
 yamlfix                                                      *ale-yaml-yamlfix*
 
 Website: https://lyz-code.github.io/yamlfix
diff --git a/doc/ale.txt b/doc/ale.txt
index 19a8dd2f..4e576284 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -3232,6 +3232,7 @@ documented in additional help files.
     prettier..............................|ale-yaml-prettier|
     spectral..............................|ale-yaml-spectral|
     swaglint..............................|ale-yaml-swaglint|
+    yaml-language-server..................|ale-yaml-language-server|
     yamlfix...............................|ale-yaml-yamlfix|
     yamllint..............................|ale-yaml-yamllint|
   yang....................................|ale-yang-options|
diff --git a/supported-tools.md b/supported-tools.md
index 1d7b7583..75b22d94 100644
--- a/supported-tools.md
+++ b/supported-tools.md
@@ -649,6 +649,7 @@ formatting.
   * [prettier](https://github.com/prettier/prettier)
   * [spectral](https://github.com/stoplightio/spectral)
   * [swaglint](https://github.com/byCedric/swaglint)
+  * [yaml-language-server](https://github.com/redhat-developer/yaml-language-server)
   * [yamlfix](https://lyz-code.github.io/yamlfix)
   * [yamllint](https://yamllint.readthedocs.io/)
 * YANG
diff --git a/test/linter/test_yaml_ls.vader b/test/linter/test_yaml_ls.vader
new file mode 100644
index 00000000..449ce8c3
--- /dev/null
+++ b/test/linter/test_yaml_ls.vader
@@ -0,0 +1,21 @@
+Before:
+  call ale#assert#SetUpLinterTest('yaml', 'ls')
+
+After:
+  call ale#assert#TearDownLinterTest()
+
+Execute(should set correct defaults):
+  AssertLinter 'yaml-language-server', ale#Escape('yaml-language-server') . ' --stdio'
+
+Execute(should set correct LSP values):
+  call ale#test#SetFilename('../test-files/yaml/test.yaml')
+
+  AssertLSPLanguage 'yaml'
+  AssertLSPOptions {}
+  AssertLSPConfig {}
+  AssertLSPProject ale#path#Simplify(g:dir . '/../test-files/yaml')
+
+Execute(should accept configuration settings):
+  AssertLSPConfig {}
+  let b:ale_yaml_ls_config = {'yaml': {'hover': v:false, 'completion': v:true}}
+  AssertLSPConfig {'yaml': {'hover': v:false, 'completion': v:true}}
diff --git a/test/test-files/yaml/test.yaml b/test/test-files/yaml/test.yaml
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/test/test-files/yaml/test.yaml