Cursor and marks positions are restored after the beautification

Zeus's code is used (with small changes) from here:
https://github.com/ZeusTheTrueGod/vim-format-js
Thank you Zeus.

Known bug: the 'last change mark' (.) restore doesn't work.

plugin/beautifier.vim

@@ -178,6 +178,83 @@ endfunc
 
 
 
+" Helper functions for restoring mark and cursor position
+function! s:getNumberOfNonSpaceCharactersFromTheStartOfFile(position)
+  let cursorRow = a:position.line
+  let cursorColumn = a:position.column
+  let lineNumber = 1
+  let nonBlankCount = 0
+  while lineNumber <= cursorRow
+    let lineContent = getline(lineNumber)
+    if lineNumber == cursorRow
+      let lineContent = strpart(lineContent,0,cursorColumn)
+    endif
+    let charIndex = 0
+    while charIndex < len(lineContent)
+      let char = strpart(lineContent,charIndex,1)
+      if match(char,'\s\|\n\|\r') == -1
+        let nonBlankCount = nonBlankCount + 1
+      endif
+      let charIndex = charIndex + 1
+    endwhile
+    "echo nonBlankCount
+    let lineNumber = lineNumber + 1
+  endwhile
+  return nonBlankCount
+endfunction
+
+
+
+"Converts number of non blank characters to cursor position (line and column)
+function! s:getCursorPosition(numberOfNonBlankCharactersFromTheStartOfFile)
+  "echo a:numberOfNonBlankCharactersFromTheStartOfFile
+  let lineNumber = 1
+  let nonBlankCount = 0
+  while lineNumber <= line('$')
+    let lineContent = getline(lineNumber)
+    let charIndex = 0
+    while charIndex < len(lineContent)
+      let char = strpart(lineContent,charIndex,1)
+      if match(char,'\s\|\n\|\r') == -1
+        let nonBlankCount = nonBlankCount + 1
+      endif
+      let charIndex = charIndex + 1
+      if nonBlankCount == a:numberOfNonBlankCharactersFromTheStartOfFile 
+        "echo 'found position!'
+        return {'line': lineNumber,'column': charIndex}
+      end
+    endwhile
+    let lineNumber = lineNumber + 1
+  endwhile
+  "echo "Oops, nothing found!"
+endfunction
+
+
+
+"Restoring current position by number of non blank characters
+function! s:setNumberOfNonSpaceCharactersBeforeCursor(mark,numberOfNonBlankCharactersFromTheStartOfFile)
+  let location = s:getCursorPosition(a:numberOfNonBlankCharactersFromTheStartOfFile)
+  call setpos(a:mark, [0, location.line, location.column, 0])
+endfunction
+
+
+
+function! s:getCursorAndMarksPositions()
+  let localMarks = map(range(char2nr('a'), char2nr('z'))," \"'\".nr2char(v:val) ") 
+  let marks = ['.'] + localMarks
+  let result = {}
+  for positionType in marks
+    let cursorPositionAsList = getpos(positionType)
+    let cursorPosition = {'buffer': cursorPositionAsList[0], 'line': cursorPositionAsList[1], 'column': cursorPositionAsList[2]}
+    if cursorPosition.buffer == 0 && cursorPosition.line > 0
+      let result[positionType] = cursorPosition
+    endif
+  endfor
+  return result
+endfunction
+
+
+
 
 "% Declaring global variables and functions
 
@@ -225,6 +302,8 @@ endfunction
 " @param {[String]} line2 The end line on which stop formating,
 " by default '$'
 func! Beautifier(...)
+  let cursorPositions = s:getCursorAndMarksPositions()
+  call map(cursorPositions, " extend (v:val,{'characters': s:getNumberOfNonSpaceCharactersFromTheStartOfFile(v:val)}) ")
   if !exists('b:config_Beautifier')
     call s:updateConfig(g:config_Beautifier)
   endif
@@ -290,6 +369,9 @@ func! Beautifier(...)
     silent exec endline.",$g/.*/d"
   endif
 
+  for [key,value] in items(cursorPositions)
+    call s:setNumberOfNonSpaceCharactersBeforeCursor(key,value.characters)
+  endfor
   return result
 endfun
 
@@ -332,8 +414,6 @@ func! BeautifierEditorconfigHook(config)
       let config["indent_char"] = ' '
     elseif config["indent_style"] == 'tab'
       let config["indent_char"] = '\t'
-      " When the indent_char is tab, we always want to use 1 tab
-      let config["indent_size"] = 1
     endif
   endif