Support for LSP/tsserver Code Actions (dense-analysis#3437)

* Added tsserver and LSP code action support.
* tsserver refactors support added.
* Handling special case when new text is added after new line symbol.
* ale#code_action#ApplyChanges simplified.
* Initial attempt on LSP Code Actions.
* workspace/executeCommand added.
* Some null checks added.
* Add last column to LSP Code Action message.
* Pass diagnostics to LSP code action.

Previously ApplyChanges code was applied from top-to-bottom that required 
extra parameters to track progress and there was bug. I have changed code
to bottom-to-top approach as that does not require those extra parameters
and solved the bug.

Tested with typescript-language-server and it is working.

ale_linters/python/jedils.vim

@@ -0,0 +1,34 @@
+" Author: Dalius Dobravolskas <dalius.dobravolskas@gmail.com>
+" Description: https://github.com/pappasam/jedi-language-server
+
+call ale#Set('python_jedils_executable', 'jedi-language-server')
+call ale#Set('python_jedils_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('python_jedils_auto_pipenv', 0)
+
+function! ale_linters#python#jedils#GetExecutable(buffer) abort
+    if (ale#Var(a:buffer, 'python_auto_pipenv') || ale#Var(a:buffer, 'python_jedils_auto_pipenv'))
+    \ && ale#python#PipenvPresent(a:buffer)
+        return 'pipenv'
+    endif
+
+    return ale#python#FindExecutable(a:buffer, 'python_jedils', ['jedi-language-server'])
+endfunction
+
+function! ale_linters#python#jedils#GetCommand(buffer) abort
+    let l:executable = ale_linters#python#jedils#GetExecutable(a:buffer)
+
+    let l:exec_args = l:executable =~? 'pipenv$'
+    \   ? ' run jedi-language-server'
+    \   : ''
+
+    return ale#Escape(l:executable) . l:exec_args
+endfunction
+
+call ale#linter#Define('python', {
+\   'name': 'jedils',
+\   'lsp': 'stdio',
+\   'executable': function('ale_linters#python#jedils#GetExecutable'),
+\   'command': function('ale_linters#python#jedils#GetCommand'),
+\   'project_root': function('ale#python#FindProjectRoot'),
+\   'completion_filter': 'ale#completion#python#CompletionItemFilter',
+\})

autoload/ale/code_action.vim

@@ -33,35 +33,35 @@ endfunction
 
 function! s:ChangeCmp(left, right) abort
     if a:left.start.line < a:right.start.line
-        return -1
+        return 1
     endif
 
     if a:left.start.line > a:right.start.line
-        return 1
+        return -1
     endif
 
     if a:left.start.offset < a:right.start.offset
-        return -1
+        return 1
     endif
 
     if a:left.start.offset > a:right.start.offset
-        return 1
+        return -1
     endif
 
     if a:left.end.line < a:right.end.line
-        return -1
+        return 1
     endif
 
     if a:left.end.line > a:right.end.line
-        return 1
+        return -1
     endif
 
     if a:left.end.offset < a:right.end.offset
-        return -1
+        return 1
     endif
 
     if a:left.end.offset > a:right.end.offset
-        return 1
+        return -1
     endif
 
     return 0
@@ -85,29 +85,14 @@ function! ale#code_action#ApplyChanges(filename, changes, should_save) abort
         let l:pos = [1, 1]
     endif
 
-    " We have to keep track of how many lines we have added, and offset
-    " changes accordingly.
-    let l:line_offset = 0
-    let l:column_offset = 0
-    let l:last_end_line = 0
-
-    " Changes have to be sorted so we apply them from top-to-bottom.
+    " Changes have to be sorted so we apply them from bottom-to-top
     for l:code_edit in sort(copy(a:changes), function('s:ChangeCmp'))
-        if l:code_edit.start.line isnot l:last_end_line
-            let l:column_offset = 0
-        endif
-
-        let l:line = l:code_edit.start.line + l:line_offset
-        let l:column = l:code_edit.start.offset + l:column_offset
-        let l:end_line = l:code_edit.end.line + l:line_offset
-        let l:end_column = l:code_edit.end.offset + l:column_offset
+        let l:line = l:code_edit.start.line
+        let l:column = l:code_edit.start.offset
+        let l:end_line = l:code_edit.end.line
+        let l:end_column = l:code_edit.end.offset
         let l:text = l:code_edit.newText
 
-        let l:cur_line = l:pos[0]
-        let l:cur_column = l:pos[1]
-
-        let l:last_end_line = l:end_line
-
         " Adjust the ends according to previous edits.
         if l:end_line > len(l:lines)
             let l:end_line_len = 0
@@ -125,6 +110,12 @@ function! ale#code_action#ApplyChanges(filename, changes, should_save) abort
             let l:start = l:lines[: l:line - 2]
         endif
 
+        " Special case when text must be added after new line
+        if l:column > len(l:lines[l:line - 1])
+            call extend(l:start, [l:lines[l:line - 1]])
+            let l:column = 1
+        endif
+
         if l:column is 1
             " We need to handle column 1 specially, because we can't slice an
             " empty string ending on index 0.
@@ -140,7 +131,6 @@ function! ale#code_action#ApplyChanges(filename, changes, should_save) abort
         let l:lines = l:start + l:middle + l:lines[l:end_line :]
 
         let l:current_line_offset = len(l:lines) - l:lines_before_change
-        let l:line_offset += l:current_line_offset
         let l:column_offset = len(l:middle[-1]) - l:end_line_len
 
         let l:pos = s:UpdateCursor(l:pos,
@@ -215,3 +205,61 @@ function! s:UpdateCursor(cursor, start, end, offset) abort
 
     return [l:cur_line, l:cur_column]
 endfunction
+
+function! ale#code_action#GetChanges(workspace_edit) abort
+    let l:changes = {}
+
+    if has_key(a:workspace_edit, 'changes') && !empty(a:workspace_edit.changes)
+        return a:workspace_edit.changes
+    elseif has_key(a:workspace_edit, 'documentChanges')
+        let l:document_changes = []
+
+        if type(a:workspace_edit.documentChanges) is v:t_dict
+        \ && has_key(a:workspace_edit.documentChanges, 'edits')
+            call add(l:document_changes, a:workspace_edit.documentChanges)
+        elseif type(a:workspace_edit.documentChanges) is v:t_list
+            let l:document_changes = a:workspace_edit.documentChanges
+        endif
+
+        for l:text_document_edit in l:document_changes
+            let l:filename = l:text_document_edit.textDocument.uri
+            let l:edits = l:text_document_edit.edits
+            let l:changes[l:filename] = l:edits
+        endfor
+    endif
+
+    return l:changes
+endfunction
+
+function! ale#code_action#BuildChangesList(changes_map) abort
+    let l:changes = []
+
+    for l:file_name in keys(a:changes_map)
+        let l:text_edits = a:changes_map[l:file_name]
+        let l:text_changes = []
+
+        for l:edit in l:text_edits
+            let l:range = l:edit.range
+            let l:new_text = l:edit.newText
+
+            call add(l:text_changes, {
+            \ 'start': {
+            \   'line': l:range.start.line + 1,
+            \   'offset': l:range.start.character + 1,
+            \ },
+            \ 'end': {
+            \   'line': l:range.end.line + 1,
+            \   'offset': l:range.end.character + 1,
+            \ },
+            \ 'newText': l:new_text,
+            \})
+        endfor
+
+        call add(l:changes, {
+        \   'fileName': ale#path#FromURI(l:file_name),
+        \   'textChanges': l:text_changes,
+        \})
+    endfor
+
+    return l:changes
+endfunction