refactor diagnostics get buffer first error line to use the new internal state (#1003)

Author: prabirshrestha

autoload/lsp.vim

@@ -1125,7 +1125,7 @@ endfunction
 
 " Return first error line or v:null if there are no errors
 function! lsp#get_buffer_first_error_line() abort
-    return lsp#ui#vim#diagnostics#get_buffer_first_error_line()
+    return lsp#internal#diagnostics#first_line#get_first_error_line({'bufnr': bufnr('%')})
 endfunction
 
 " Return UI list with window/workDoneProgress

autoload/lsp/internal/diagnostics/first_line.vim

@@ -0,0 +1,26 @@
+" Return first error line or v:null if there are no errors
+" available.
+" options = {
+"   'bufnr': '',        " optional
+" }
+function! lsp#internal#diagnostics#first_line#get_first_error_line(options) abort
+    let l:bufnr = get(a:options, 'bufnr', bufnr('%'))
+
+    if !lsp#internal#diagnostics#state#_is_enabled_for_buffer(l:bufnr)
+        return v:null
+    endif
+
+    let l:uri = lsp#utils#get_buffer_uri(l:bufnr)
+    let l:diagnostics_by_server = lsp#internal#diagnostics#state#_get_all_diagnostics_grouped_by_server_for_uri(l:uri)
+
+    let l:first_error_line = v:null
+    for l:diagnostics_response in values(l:diagnostics_by_server)
+        for l:diagnostics in l:diagnostics_response['params']['diagnostics']
+            let l:severity = get(l:diagnostics, 'severity', 1)
+            if l:severity ==# 1 && (l:first_error_line ==# v:null || l:first_error_line ># l:diagnostics['range']['start']['line'])
+                let l:first_error_line = l:diagnostics['range']['start']['line']
+            endif
+        endfor
+    endfor
+    return l:first_error_line ==# v:null ? v:null : l:first_error_line + 1
+endfunction

autoload/lsp/ui/vim/diagnostics.vim

@@ -208,18 +208,4 @@ function! s:compare_diagnostics(d1, d2) abort
         return l:line1 > l:line2 ? 1 : -1
     endif
 endfunction
-
-function! lsp#ui#vim#diagnostics#get_buffer_first_error_line() abort
-    let l:uri = lsp#utils#get_buffer_uri()
-    let [l:has_diagnostics, l:diagnostics] = s:get_diagnostics(l:uri)
-    let l:first_error_line = v:null
-    for [l:server_name, l:data] in items(l:diagnostics)
-        for l:diag in l:data['response']['params']['diagnostics']
-            if s:severity_of(l:diag) ==# 1 && (l:first_error_line ==# v:null || l:first_error_line ># l:diag['range']['start']['line'])
-                let l:first_error_line = l:diag['range']['start']['line']
-            endif
-        endfor
-    endfor
-    return l:first_error_line ==# v:null ? v:null : l:first_error_line + 1
-endfunction
 " vim sw=4 ts=4 et