Add flag to disable diagnostics (#197)

* Add switch, g:lsp_diagnostics_enabled, to disable support for diagnostics

* Reduce PR changeset

Author: iamFIREcracker

README.md

@@ -69,6 +69,18 @@ Refer to docs on configuring omnifunc or [asyncomplete.vim](https://github.com/p
 
 ### Diagnostics
 
+Document diagnostics (e.g. warnings, errors) are enabled by default, but if you
+preferred to turn them off and use other plugins instead (like
+[Neomake](https://github.com/neomake/neomake) or
+[ALE](https://github.com/neomake/neomake), set `g:lsp_diagnostics_enabled` to
+`0`:
+
+```viml
+let g:lsp_diagnostics_enabled = 0         " disable diagnostics support
+```
+
+#### Signs
+
 ```viml
 let g:lsp_signs_enabled = 1         " enable signs
 let g:lsp_diagnostics_echo_cursor = 1 " enable echo under cursor when in normal mode

autoload/lsp.vim

@@ -35,7 +35,7 @@ function! lsp#enable() abort
         let s:already_setup = 1
     endif
     let s:enabled = 1
-    if g:lsp_signs_enabled
+    if g:lsp_diagnostics_enabled && g:lsp_signs_enabled
         call lsp#ui#vim#signs#enable()
     endif
     call s:register_events()
@@ -514,7 +514,7 @@ function! s:on_notification(server_name, id, data, event) abort
 
     if lsp#client#is_server_instantiated_notification(a:data)
         if has_key(l:response, 'method')
-            if l:response['method'] ==# 'textDocument/publishDiagnostics'
+            if g:lsp_diagnostics_enabled && l:response['method'] ==# 'textDocument/publishDiagnostics'
                 call lsp#ui#vim#diagnostics#handle_text_document_publish_diagnostics(a:server_name, a:data)
             endif
         endif

autoload/lsp/ui/vim/diagnostics.vim

@@ -15,6 +15,11 @@ function! lsp#ui#vim#diagnostics#handle_text_document_publish_diagnostics(server
 endfunction
 
 function! lsp#ui#vim#diagnostics#document_diagnostics() abort
+    if !g:lsp_diagnostics_enabled
+        call lsp#utils#error('Diagnostics manually disabled -- g:lsp_diagnostics_enabled = 0')
+        return
+    endif
+
     let l:uri = lsp#utils#get_buffer_uri()
 
     let [l:has_diagnostics, l:diagnostics] = s:get_diagnostics(l:uri)

doc/vim-lsp.txt

@@ -10,6 +10,7 @@ CONTENTS                                                  *vim-lsp-contents*
       Configure                   |vim-lsp-configure-source|
       Wiki                        |vim-lsp-configure-wiki|
     Options			|vim-lsp-options|
+      g:lsp_diagnostics_enabled   |g:lsp_diagnostics_enabled|
       g:lsp_auto_enable           |g:lsp_auto_enable|
       g:lsp_preview_keep_focus    |g:lsp_preview_keep_focus|
     Functions			|vim-lsp-functions|
@@ -93,6 +94,17 @@ to https://github.com/prabirshrestha/vim-lsp/wiki/Servers
 ===============================================================================
 Options                                                   *vim-lsp-options*
 
+g:lsp_diagnostics_enabled                       *g:lsp_diagnostics_enabled*
+    Type: |Number|
+    Default: `1`
+
+    Enable support for document diagnostics like warnings and error messages.
+    enabling vim-lsp during startup.
+
+    Example:
+	let g:lsp_diagnostics_enabled = 1
+	let g:lsp_diagnostics_enabled = 0
+
 g:lsp_auto_enable                                       *g:lsp_auto_enable*
     Type: |Number|
     Default: `1`

plugin/lsp.vim

@@ -13,6 +13,7 @@ let g:lsp_signs_error = get(g:, 'lsp_signs_error', {})
 let g:lsp_signs_warning = get(g:, 'lsp_signs_warning', {})
 let g:lsp_signs_information = get(g:, 'lsp_signs_information', {})
 let g:lsp_signs_hint = get(g:, 'lsp_signs_hint', {})
+let g:lsp_diagnostics_enabled = get(g:, 'lsp_diagnostics_enabled', 1)
 let g:lsp_diagnostics_echo_cursor = get(g:, 'lsp_diagnostics_echo_cursor', 0)
 let g:lsp_diagnostics_echo_delay = get(g:, 'lsp_diagnostics_echo_delay', 500)
 let g:lsp_next_sign_id = get(g:, 'lsp_next_sign_id', 6999)