the PR natebosch#449 requests the ability to handle multiple definitions.

This branch is concerned with compability.
It should:
* enable jumping to (1) declaration => with split, only one binding
* extend the existing documentation => reference parent impl
* extend the existing tests => copy dart-test

Author: Thomas Hage

README.md

@@ -148,6 +148,12 @@ using the default mappings) to jump to the location of the definition. When
 multiple definitions are available, the quickfix list will be opened.
 If the cursor moves before the server responds the response will be ignored.
 
+### Jump to declaration
+
+While the cursor is on any identifier call `LSClientGoToDeclaration` (`gd` if
+using the default mappings) to jump to the location of the declaration.
+If the cursor moves before the server responds the response will be ignored.
+
 ### Find references
 
 While the cursor is on any identifier call `LSClientFindReferences` (`gr` if

autoload/lsc/config.vim

@@ -3,6 +3,8 @@ if !exists('s:initialized')
   let s:default_maps = {
       \ 'GoToDefinition': '<C-]>',
       \ 'GoToDefinitionSplit': ['<C-W>]', '<C-W><C-]>'],
+      \ 'GoToDeclaration': 'gd',
+      \ 'GoToDeclarationSplit': ['<C-W>]', '<C-W>gd'],
       \ 'FindReferences': 'gr',
       \ 'NextReference': '<C-n>',
       \ 'PreviousReference': '<C-p>',
@@ -54,6 +56,8 @@ function! lsc#config#mapKeys() abort
   for l:command in [
       \ 'GoToDefinition',
       \ 'GoToDefinitionSplit',
+      \ 'GoToDeclaration',
+      \ 'GoToDeclarationSplit',
       \ 'FindReferences',
       \ 'NextReference',
       \ 'PreviousReference',

autoload/lsc/reference.vim

@@ -1,20 +1,28 @@
 let s:popup_id = 0
 
+function! lsc#reference#goToDeclaration(mods, issplit) abort
+  call lsc#file#flushChanges()
+  call lsc#server#userCall('textDocument/declaration',
+      \ lsc#params#documentPosition(),
+      \ lsc#util#gateResult('GoTo',
+      \   function('<SID>GoTo', ['declaration', a:mods, a:issplit])))
+endfunction
+
 function! lsc#reference#goToDefinition(mods, issplit) abort
   call lsc#file#flushChanges()
   call lsc#server#userCall('textDocument/definition',
       \ lsc#params#documentPosition(),
-      \ lsc#util#gateResult('GoToDefinition',
-      \   function('<SID>GoToDefinition', [a:mods, a:issplit])))
+      \ lsc#util#gateResult('GoTo',
+      \   function('<SID>GoTo', ['definition', a:mods, a:issplit])))
 endfunction
 
-function! s:GoToDefinition(mods, issplit, result) abort
+function! s:GoTo(label, mods, issplit, result) abort
   if type(a:result) == type(v:null) ||
       \ (type(a:result) == type([]) && len(a:result) == 0)
-    call lsc#message#error('No definition found')
+    call lsc#message#error('No'. a:label .'found')
     return
   endif
-  if type(a:result) == type([]) && len(a:result) == 1
+  if type(a:result) == type([]) && (a:label ==# 'declaration' || len(a:result) == 1)
     let l:location = a:result[0]
   elseif type(a:result) == type([]) && len(a:result) > 2
     call s:setQuickFixLocations('Definitions', a:result)

doc/lsc.txt

@@ -76,6 +76,14 @@ will default to opening a vertical split, while >
 <
 will prefer a new tab.
 
+                                                *:LSClientGoToDeclaration*
+Similiar to |LSClientGoToDefinition| but expects only a single result.
+This is not compliant to the current protocol since it accepts multiple
+declaration results as well.
+
+                                                *:LSClientGoToDeclarationSplit*
+In accordance to |LSClientGoToDeclaration| and |LSClientGoToDefinitionSplit|.
+
                                                 *:LSClientFindReferences*
 Populate the |quickfix| with a list of location which reference the element
 under the cursor, including it's definition. Sends a "textDocument/references"

plugin/lsc.vim

@@ -25,6 +25,10 @@ command! LSClientGoToDefinitionSplit
     \ call lsc#reference#goToDefinition(<q-mods>, 1)
 command! LSClientGoToDefinition
     \ call lsc#reference#goToDefinition(<q-mods>, 0)
+command! LSClientGoToDeclarationSplit
+    \ call lsc#reference#goToDeclaration(<q-mods>, 1)
+command! LSClientGoToDeclaration
+    \ call lsc#reference#goToDeclaration(<q-mods>, 0)
 command! LSClientFindReferences call lsc#reference#findReferences()
 command! LSClientNextReference call lsc#reference#findNext(1)
 command! LSClientPreviousReference call lsc#reference#findNext(-1)

test/integration/test/vim_test.dart

@@ -35,6 +35,11 @@ void main() {
       expect(result, '2');
     });
 
+    test('loads plugin', () async {
+      final result = await vim.expr('exists(\':LSClientGoToDeclaration\')');
+      expect(result, '1');
+    });
+
     test('opens files, has filetype detection', () async {
       await vim.edit('foo.txt');
       expect(await vim.expr('&ft'), 'text');