Add yamllint and prettier to openapi.

This commit enables yamllint and prettier on openapi files.

autoload/ale/fix/registry.vim

@@ -102,7 +102,7 @@ let s:default_registry = {
 \   },
 \   'prettier': {
 \       'function': 'ale#fixers#prettier#Fix',
-\       'suggested_filetypes': ['javascript', 'typescript', 'css', 'less', 'scss', 'json', 'json5', 'graphql', 'markdown', 'vue', 'html', 'yaml'],
+\       'suggested_filetypes': ['javascript', 'typescript', 'css', 'less', 'scss', 'json', 'json5', 'graphql', 'markdown', 'vue', 'html', 'yaml', 'openapi'],
 \       'description': 'Apply prettier to a file.',
 \   },
 \   'prettier_eslint': {

autoload/ale/fixers/prettier.vim

@@ -83,6 +83,7 @@ function! ale#fixers#prettier#ApplyFixForVersion(buffer, version) abort
         \    'markdown': 'markdown',
         \    'vue': 'vue',
         \    'yaml': 'yaml',
+        \    'openapi': 'yaml',
         \    'html': 'html',
         \}
 

autoload/ale/handlers/yamllint.vim

@@ -0,0 +1,39 @@
+function! ale#handlers#yamllint#GetCommand(buffer) abort
+    return '%e' . ale#Pad(ale#Var(a:buffer, 'yaml_yamllint_options'))
+    \   . ' -f parsable %t'
+endfunction
+
+function! ale#handlers#yamllint#Handle(buffer, lines) abort
+    " Matches patterns line the following:
+    " something.yaml:1:1: [warning] missing document start "---" (document-start)
+    " something.yml:2:1: [error] syntax error: expected the node content, but found '<stream end>'
+    let l:pattern = '\v^.*:(\d+):(\d+): \[(error|warning)\] (.+)$'
+    let l:output = []
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        let l:item = {
+        \   'lnum': l:match[1] + 0,
+        \   'col': l:match[2] + 0,
+        \   'text': l:match[4],
+        \   'type': l:match[3] is# 'error' ? 'E' : 'W',
+        \}
+
+        let l:code_match = matchlist(l:item.text, '\v^(.+) \(([^)]+)\)$')
+
+        if !empty(l:code_match)
+            if l:code_match[2] is# 'trailing-spaces'
+            \&& !ale#Var(a:buffer, 'warn_about_trailing_whitespace')
+                " Skip warnings for trailing whitespace if the option is off.
+                continue
+            endif
+
+            let l:item.text = l:code_match[1]
+            let l:item.code = l:code_match[2]
+        endif
+
+        call add(l:output, l:item)
+    endfor
+
+    return l:output
+endfunction
+