Add TSServer support for JavaScript files

ale_linters/javascript/tsserver.vim

@@ -0,0 +1,26 @@
+" Author: Chaucerbao, w0rp <devw0rp@gmail.com>
+" Description: tsserver integration for ALE
+
+call ale#Set('javascript_tsserver_executable', 'tsserver')
+call ale#Set('javascript_tsserver_config_path', '')
+call ale#Set('javascript_tsserver_use_global', get(g:, 'ale_use_global_executables', 0))
+
+" These functions need to be defined just to comply with the API for LSP.
+function! ale_linters#javascript#tsserver#GetProjectRoot(buffer) abort
+    return ''
+endfunction
+
+function! ale_linters#javascript#tsserver#GetExecutable(buffer) abort
+    return ale#node#FindExecutable(a:buffer, 'javascript_tsserver', [
+    \   'node_modules/.bin/tsserver',
+    \])
+endfunction
+
+call ale#linter#Define('javascript', {
+\   'name': 'tsserver',
+\   'lsp': 'tsserver',
+\   'executable_callback': 'ale_linters#javascript#tsserver#GetExecutable',
+\   'command_callback': 'ale_linters#javascript#tsserver#GetExecutable',
+\   'project_root_callback': 'ale_linters#javascript#tsserver#GetProjectRoot',
+\   'language': '',
+\})