Truncate diagnostics cursor message when message is too long (#191)

* truncate diagnostics message

* fix echo with truncation

Author: prabirshrestha

autoload/lsp/ui/vim/diagnostics/echo.vim

@@ -22,7 +22,7 @@ endfunction
 function! s:echo_diagnostics_under_cursor(...) abort
     let l:diagnostic = lsp#ui#vim#diagnostics#get_diagnostics_under_cursor()
     if !empty(l:diagnostic) && has_key(l:diagnostic, 'message')
-        echo 'LSP: '. substitute(l:diagnostic['message'], '\n\+', ' ', 'g')
+        call lsp#utils#echo_with_truncation('LSP: '. substitute(l:diagnostic['message'], '\n\+', ' ', 'g'))
     endif
 endfunction
 

autoload/lsp/utils.vim

@@ -138,3 +138,14 @@ function! lsp#utils#error(msg) abort
     echom a:msg
     echohl NONE
 endfunction
+
+function! lsp#utils#echo_with_truncation(msg) abort
+    let l:msg = a:msg
+    let l:winwidth = winwidth(0)
+
+    if l:winwidth < strdisplaywidth(l:msg)
+        let l:msg = l:msg[:l:winwidth - 5] . '...'
+    endif
+
+    exec 'echo l:msg'
+endfunction