diff --git a/autoload/nerdtree.vim b/autoload/nerdtree.vim
index c2f7f1c..0e509b2 100644
--- a/autoload/nerdtree.vim
+++ b/autoload/nerdtree.vim
@@ -15,7 +15,7 @@ function! nerdtree#version(...)
         let l:changelog = readfile(join([s:rootNERDTreePath, 'CHANGELOG.md'], nerdtree#slash()))
         let l:line = 0
         while l:line <= len(l:changelog)
-            if l:changelog[l:line] =~ '\d\+\.\d\+'
+            if l:changelog[l:line] =~# '\d\+\.\d\+'
                 let l:text = substitute(l:changelog[l:line], '.*\(\d\+.\d\+\).*', '\1', '')
                 let l:text .= substitute(l:changelog[l:line+1], '^.\{-}\(\.\d\+\).\{-}:\(.*\)', a:0>0 ? '\1:\2' : '\1', '')
                 break
@@ -122,15 +122,15 @@ function! nerdtree#compareNodesBySortKey(n1, n2)
         " Compare chunks upto common length.
         " If chunks have different type, the one which has
         " integer type is the lesser.
-        if type(sortKey1[i]) == type(sortKey2[i])
+        if type(sortKey1[i]) ==# type(sortKey2[i])
             if sortKey1[i] <# sortKey2[i]
                 return - 1
             elseif sortKey1[i] ># sortKey2[i]
                 return 1
             endif
-        elseif type(sortKey1[i]) == v:t_number
+        elseif type(sortKey1[i]) ==# v:t_number
             return -1
-        elseif type(sortKey2[i]) == v:t_number
+        elseif type(sortKey2[i]) ==# v:t_number
             return 1
         endif
         let i = i + 1
@@ -175,7 +175,7 @@ endfunction
 
 " FUNCTION: nerdtree#has_opt(options, name) {{{2
 function! nerdtree#has_opt(options, name)
-    return has_key(a:options, a:name) && a:options[a:name] == 1
+    return has_key(a:options, a:name) && a:options[a:name] ==# 1
 endfunction
 
 " FUNCTION: nerdtree#loadClassFiles() {{{2
diff --git a/autoload/nerdtree/ui_glue.vim b/autoload/nerdtree/ui_glue.vim
index 96d0fa7..b500230 100644
--- a/autoload/nerdtree/ui_glue.vim
+++ b/autoload/nerdtree/ui_glue.vim
@@ -146,7 +146,7 @@ endfunction
 " Associate the current node with the given name
 function! nerdtree#ui_glue#bookmarkNode(...)
     let currentNode = g:NERDTreeFileNode.GetSelected()
-    if currentNode != {}
+    if currentNode !=# {}
         let name = a:1
         if empty(name)
             let name = currentNode.path.getLastPathComponent(0)
@@ -187,7 +187,7 @@ endfunction
 function! nerdtree#ui_glue#clearBookmarks(bookmarks)
     if a:bookmarks ==# ''
         let currentNode = g:NERDTreeFileNode.GetSelected()
-        if currentNode != {}
+        if currentNode !=# {}
             call currentNode.clearBookmarks()
         endif
     else
@@ -236,7 +236,7 @@ endfunction
 " FUNCTION: s:closeTreeWindow() {{{1
 " close the tree window
 function! s:closeTreeWindow()
-    if b:NERDTree.isWinTree() && b:NERDTree.previousBuf() != -1
+    if b:NERDTree.isWinTree() && b:NERDTree.previousBuf() !=# -1
         exec 'buffer ' . b:NERDTree.previousBuf()
     else
         if winnr('$') > 1
@@ -258,7 +258,7 @@ function! s:deleteBookmark(bookmark)
     echo | redraw
     let l:selection = confirm(l:message, l:choices, 1, 'Warning')
 
-    if l:selection != 1
+    if l:selection !=# 1
         call nerdtree#echo('bookmark not deleted')
         return
     endif
@@ -335,7 +335,7 @@ endfunction
 "Checks if the click should open the current node
 function! s:handleLeftClick()
     let currentNode = g:NERDTreeFileNode.GetSelected()
-    if currentNode != {}
+    if currentNode !=# {}
 
         "the dir arrows are multibyte chars, and vim's string functions only
         "deal with single bytes - so split the line up with the hack below and
diff --git a/lib/nerdtree/bookmark.vim b/lib/nerdtree/bookmark.vim
index ccb6f98..b457a8a 100644
--- a/lib/nerdtree/bookmark.vim
+++ b/lib/nerdtree/bookmark.vim
@@ -93,7 +93,7 @@ function! s:Bookmark.CacheBookmarks(silent)
         for i in bookmarkStrings
 
             "ignore blank lines
-            if i != ''
+            if i !=# ''
 
                 let name = substitute(i, '^\(.\{-}\) .*$', '\1', '')
                 let path = substitute(i, '^.\{-} \(.*\)$', '\1', '')
@@ -123,13 +123,13 @@ endfunction
 " option. Supports the s:Bookmark.SortBookmarksList() method.
 function! s:Bookmark.CompareBookmarksByName(firstBookmark, secondBookmark)
     let l:result = 0
-    if g:NERDTreeBookmarksSort == 1
+    if g:NERDTreeBookmarksSort ==# 1
         if a:firstBookmark.name <? a:secondBookmark.name
             let l:result = -1
         elseif a:firstBookmark.name >? a:secondBookmark.name
             let l:result = 1
         endif
-    elseif g:NERDTreeBookmarksSort == 2
+    elseif g:NERDTreeBookmarksSort ==# 2
         if a:firstBookmark.name <# a:secondBookmark.name
             let l:result = -1
         elseif a:firstBookmark.name ># a:secondBookmark.name
@@ -198,7 +198,7 @@ endfunction
 function! s:Bookmark.GetSelected()
     let line = getline('.')
     let name = substitute(line, '^>\(.\{-}\) .\+$', '\1', '')
-    if name != line
+    if name !=# line
         try
             return s:Bookmark.BookmarkFor(name)
         catch /^NERDTree.BookmarkNotFoundError/
diff --git a/lib/nerdtree/key_map.vim b/lib/nerdtree/key_map.vim
index 5c96c61..f3268c2 100644
--- a/lib/nerdtree/key_map.vim
+++ b/lib/nerdtree/key_map.vim
@@ -53,7 +53,7 @@ function! s:KeyMap.bind()
     endif
     let keymapInvokeString = escape(keymapInvokeString, '\')
 
-    let premap = self.key == '<LeftRelease>' ? ' <LeftRelease>' : ' '
+    let premap = self.key ==# '<LeftRelease>' ? ' <LeftRelease>' : ' '
 
     exec 'nnoremap <buffer> <silent> '. self.key . premap . ':call nerdtree#ui_glue#invokeKeyMap("'. keymapInvokeString .'")<cr>'
 endfunction
@@ -66,7 +66,7 @@ endfunction
 "FUNCTION: KeyMap.invoke() {{{1
 "Call the KeyMaps callback function
 function! s:KeyMap.invoke(...)
-    let Callback = type(self.callback) == type(function('tr')) ? self.callback : function(self.callback)
+    let Callback = type(self.callback) ==# type(function('tr')) ? self.callback : function(self.callback)
     if a:0
         call Callback(a:1)
     else
@@ -143,7 +143,7 @@ function! s:KeyMap.Create(options)
     let opts = extend({'scope': 'all', 'quickhelpText': ''}, copy(a:options))
 
     "dont override other mappings unless the 'override' option is given
-    if get(opts, 'override', 0) == 0 && !empty(s:KeyMap.FindFor(opts['key'], opts['scope']))
+    if get(opts, 'override', 0) ==# 0 && !empty(s:KeyMap.FindFor(opts['key'], opts['scope']))
         return
     end
 
diff --git a/lib/nerdtree/menu_controller.vim b/lib/nerdtree/menu_controller.vim
index a3b168b..ca93efa 100644
--- a/lib/nerdtree/menu_controller.vim
+++ b/lib/nerdtree/menu_controller.vim
@@ -45,12 +45,12 @@ function! s:MenuController.showMenu()
         call self._restoreOptions()
 
         " Redraw when Ctrl-C or Esc is received.
-        if !l:done || self.selection == -1
+        if !l:done || self.selection ==# -1
             redraw!
         endif
     endtry
 
-    if self.selection != -1
+    if self.selection !=# -1
         let l:m = self._current()
         call l:m.execute()
     endif
@@ -73,7 +73,7 @@ function! s:MenuController._echoPrompt()
         echo '========================================================='
 
         for i in range(0, len(self.menuItems)-1)
-            if self.selection == i
+            if self.selection ==# i
                 echo '> ' . self.menuItems[i].text
             else
                 echo '  ' . self.menuItems[i].text
@@ -92,20 +92,20 @@ endfunction
 "change the selection (if appropriate) and return 1 if the user has made
 "their choice, 0 otherwise
 function! s:MenuController._handleKeypress(key)
-    if a:key == g:NERDTreeMenuDown
+    if a:key ==# g:NERDTreeMenuDown
         call self._cursorDown()
-    elseif a:key == g:NERDTreeMenuUp
+    elseif a:key ==# g:NERDTreeMenuUp
         call self._cursorUp()
-    elseif a:key == nr2char(27) "escape
+    elseif a:key ==# nr2char(27) "escape
         let self.selection = -1
         return 1
-    elseif a:key == "\r" || a:key == "\n" "enter and ctrl-j
+    elseif a:key ==# "\r" || a:key ==# "\n" "enter and ctrl-j
         return 1
     else
         let index = self._nextIndexFor(a:key)
-        if index != -1
+        if index !=# -1
             let self.selection = index
-            if len(self._allIndexesFor(a:key)) == 1
+            if len(self._allIndexesFor(a:key)) ==# 1
                 return 1
             endif
         endif
@@ -120,7 +120,7 @@ function! s:MenuController._allIndexesFor(shortcut)
     let toReturn = []
 
     for i in range(0, len(self.menuItems)-1)
-        if self.menuItems[i].shortcut == a:shortcut
+        if self.menuItems[i].shortcut ==# a:shortcut
             call add(toReturn, i)
         endif
     endfor
@@ -133,13 +133,13 @@ endfunction
 "current cursor location and wraps around to the top again if need be
 function! s:MenuController._nextIndexFor(shortcut)
     for i in range(self.selection+1, len(self.menuItems)-1)
-        if self.menuItems[i].shortcut == a:shortcut
+        if self.menuItems[i].shortcut ==# a:shortcut
             return i
         endif
     endfor
 
     for i in range(0, self.selection)
-        if self.menuItems[i].shortcut == a:shortcut
+        if self.menuItems[i].shortcut ==# a:shortcut
             return i
         endif
     endfor
diff --git a/lib/nerdtree/nerdtree.vim b/lib/nerdtree/nerdtree.vim
index 03878a4..a48f6a8 100644
--- a/lib/nerdtree/nerdtree.vim
+++ b/lib/nerdtree/nerdtree.vim
@@ -37,13 +37,13 @@ function! s:NERDTree.Close()
         return
     endif
 
-    if winnr('$') != 1
+    if winnr('$') !=# 1
         " Use the window ID to identify the currently active window or fall
         " back on the buffer ID if win_getid/win_gotoid are not available, in
         " which case we'll focus an arbitrary window showing the buffer.
         let l:useWinId = exists('*win_getid') && exists('*win_gotoid')
 
-        if winnr() == s:NERDTree.GetWinNum()
+        if winnr() ==# s:NERDTree.GetWinNum()
             call nerdtree#exec('wincmd p', 1)
             let l:activeBufOrWin = l:useWinId ? win_getid() : bufnr('')
             call nerdtree#exec('wincmd p', 1)
@@ -160,17 +160,17 @@ endfunction
 
 "FUNCTION: s:NERDTree.IsOpen() {{{1
 function! s:NERDTree.IsOpen()
-    return s:NERDTree.GetWinNum() != -1
+    return s:NERDTree.GetWinNum() !=# -1
 endfunction
 
 "FUNCTION: s:NERDTree.isTabTree() {{{1
 function! s:NERDTree.isTabTree()
-    return self._type == 'tab'
+    return self._type ==# 'tab'
 endfunction
 
 "FUNCTION: s:NERDTree.isWinTree() {{{1
 function! s:NERDTree.isWinTree()
-    return self._type == 'window'
+    return self._type ==# 'window'
 endfunction
 
 "FUNCTION: s:NERDTree.MustBeOpen() {{{1
diff --git a/lib/nerdtree/opener.vim b/lib/nerdtree/opener.vim
index d9a8868..d8dba34 100644
--- a/lib/nerdtree/opener.vim
+++ b/lib/nerdtree/opener.vim
@@ -45,7 +45,7 @@ function! s:Opener._checkToCloseTree(newtab)
         return
     endif
 
-    if (a:newtab && self._where == 't') || !a:newtab
+    if (a:newtab && self._where ==# 't') || !a:newtab
         call g:NERDTree.CloseIfQuitOnOpen()
     endif
 endfunction
@@ -56,7 +56,7 @@ function! s:Opener._firstUsableWindow()
     let i = 1
     while i <= winnr('$')
         let bnum = winbufnr(i)
-        if bnum != -1 && getbufvar(bnum, '&buftype') ==# ''
+        if bnum !=# -1 && getbufvar(bnum, '&buftype') ==# ''
                     \ && !getwinvar(i, '&previewwindow')
                     \ && (!getbufvar(bnum, '&modified') || &hidden)
             return i
@@ -70,23 +70,23 @@ endfunction
 " FUNCTION: Opener._gotoTargetWin() {{{1
 function! s:Opener._gotoTargetWin()
     if b:NERDTree.isWinTree()
-        if self._where == 'v'
+        if self._where ==# 'v'
             call self._newVSplit()
-        elseif self._where == 'h'
+        elseif self._where ==# 'h'
             call self._newSplit()
-        elseif self._where == 't'
+        elseif self._where ==# 't'
             tabnew
         endif
     else
         call self._checkToCloseTree(1)
 
-        if self._where == 'v'
+        if self._where ==# 'v'
             call self._newVSplit()
-        elseif self._where == 'h'
+        elseif self._where ==# 'h'
             call self._newSplit()
-        elseif self._where == 't'
+        elseif self._where ==# 't'
             tabnew
-        elseif self._where == 'p'
+        elseif self._where ==# 'p'
             call self._previousWindow()
         endif
 
@@ -108,7 +108,7 @@ function! s:Opener._isWindowUsable(winnumber)
 
     let oldwinnr = winnr()
     call nerdtree#exec(a:winnumber . 'wincmd p', 1)
-    let specialWindow = getbufvar('%', '&buftype') != '' || getwinvar('%', '&previewwindow')
+    let specialWindow = getbufvar('%', '&buftype') !=# '' || getwinvar('%', '&previewwindow')
     let modified = &modified
     call nerdtree#exec(oldwinnr . 'wincmd p', 1)
 
@@ -247,7 +247,7 @@ function! s:Opener._openDirectory(node)
     else
         if empty(self._where)
             call b:NERDTree.changeRoot(a:node)
-        elseif self._where == 't'
+        elseif self._where ==# 't'
             call g:NERDTreeCreator.CreateTabTree(a:node.path.str())
         else
             call g:NERDTreeCreator.CreateWindowTree(a:node.path.str())
@@ -296,13 +296,13 @@ function! s:Opener._reuseWindow()
 
     "check the current tab for the window
     let winnr = bufwinnr('^' . self._path.str() . '$')
-    if winnr != -1
+    if winnr !=# -1
         call nerdtree#exec(winnr . 'wincmd w', 0)
         call self._checkToCloseTree(0)
         return 1
     endif
 
-    if self._reuse == 'currenttab'
+    if self._reuse ==# 'currenttab'
         return 0
     endif
 
diff --git a/lib/nerdtree/path.vim b/lib/nerdtree/path.vim
index a77331f..6a23c7b 100644
--- a/lib/nerdtree/path.vim
+++ b/lib/nerdtree/path.vim
@@ -25,7 +25,7 @@ function! s:Path.AbsolutePathFor(pathStr)
     if l:prependWorkingDir
         let l:result = getcwd()
 
-        if l:result[-1:] == s:Path.Slash()
+        if l:result[-1:] ==# s:Path.Slash()
             let l:result = l:result . a:pathStr
         else
             let l:result = l:result . s:Path.Slash() . a:pathStr
@@ -57,7 +57,7 @@ function! s:Path.cacheDisplayString() abort
             call add(self._bookmarkNames, i.name)
         endif
     endfor
-    if !empty(self._bookmarkNames) && g:NERDTreeMarkBookmarks == 1
+    if !empty(self._bookmarkNames) && g:NERDTreeMarkBookmarks ==# 1
         let self.cachedDisplayString = self.addDelimiter(self.cachedDisplayString) . ' {' . join(self._bookmarkNames) . '}'
     endif
 
@@ -87,7 +87,7 @@ function! s:Path.changeToDir()
     endif
 
     try
-        if g:NERDTreeUseTCD && exists(':tcd') == 2
+        if g:NERDTreeUseTCD && exists(':tcd') ==# 2
             execute 'tcd ' . dir
             call nerdtree#echo("Tab's CWD is now: " . getcwd())
         else
@@ -201,7 +201,7 @@ function! s:Path.copy(dest)
 
     let cmd = cmd_prefix . ' ' . escape(self.str(), self._escChars()) . ' ' . escape(a:dest, self._escChars())
     let success = system(cmd)
-    if v:shell_error != 0
+    if v:shell_error !=# 0
         throw "NERDTree.CopyError: Could not copy '". self.str() ."' to: '" . a:dest . "'"
     endif
 endfunction
@@ -258,7 +258,7 @@ function! s:Path.delete()
         let cmd = g:NERDTreeRemoveDirCmd . self.str({'escape': 1})
         let success = system(cmd)
 
-        if v:shell_error != 0
+        if v:shell_error !=# 0
             throw "NERDTree.PathDeletionError: Could not delete directory: '" . self.str() . "'"
         endif
     else
@@ -269,7 +269,7 @@ function! s:Path.delete()
             let success = delete(self.str())
         endif
 
-        if success != 0
+        if success !=# 0
             throw "NERDTree.PathDeletionError: Could not delete file: '" . self.str() . "'"
         endif
     endif
@@ -303,7 +303,7 @@ endfunction
 " If running windows, cache the drive letter for this path
 function! s:Path.extractDriveLetter(fullpath)
     if nerdtree#runningWindows()
-        if a:fullpath =~ '^\(\\\\\|\/\/\)'
+        if a:fullpath =~# '^\(\\\\\|\/\/\)'
             "For network shares, the 'drive' consists of the first two parts of the path, i.e. \\boxname\share
             let self.drive = substitute(a:fullpath, '^\(\(\\\\\|\/\/\)[^\\\/]*\(\\\|\/\)[^\\\/]*\).*', '\1', '')
             let self.drive = substitute(self.drive, '/', '\', 'g')
@@ -402,7 +402,7 @@ function! s:Path._splitChunks(path)
     let i = 0
     while i < len(chunks)
         "convert number literals to numbers
-        if match(chunks[i], '^\d\+$') == 0
+        if match(chunks[i], '^\d\+$') ==# 0
             let chunks[i] = str2nr(chunks[i])
         endif
         let i = i + 1
@@ -418,16 +418,16 @@ function! s:Path.getSortKey()
         let metadata = []
         for tag in g:NERDTreeSortOrder
             if tag =~? '\[\[-\?timestamp\]\]'
-                let metadata += [self.isDirectory ? 0 : getftime(self.str()) * (tag =~ '-' ? -1 : 1)]
+                let metadata += [self.isDirectory ? 0 : getftime(self.str()) * (tag =~# '-' ? -1 : 1)]
             elseif tag =~? '\[\[-\?size\]\]'
-                let metadata += [self.isDirectory ? 0 : getfsize(self.str()) * (tag =~ '-' ? -1 : 1)]
+                let metadata += [self.isDirectory ? 0 : getfsize(self.str()) * (tag =~# '-' ? -1 : 1)]
             elseif tag =~? '\[\[extension\]\]'
                 let extension = matchstr(self.getLastPathComponent(0), '[^.]\+\.\zs[^.]\+$')
-                let metadata += [self.isDirectory ? '' : (extension == '' ? nr2char(str2nr('0x10ffff',16)) : extension)]
+                let metadata += [self.isDirectory ? '' : (extension ==# '' ? nr2char(str2nr('0x10ffff',16)) : extension)]
             endif
         endfor
 
-        if g:NERDTreeSortOrder[0] =~ '\[\[.*\]\]'
+        if g:NERDTreeSortOrder[0] =~# '\[\[.*\]\]'
             " Apply tags' sorting first if specified first.
             let self._sortKey = metadata + [self.getSortOrderIndex()]
         else
@@ -501,7 +501,7 @@ function! s:Path.ignore(nerdtree)
         endfor
 
         for Callback in g:NERDTree.PathFilters()
-            let Callback = type(Callback) == type(function('tr')) ? Callback : function(Callback)
+            let Callback = type(Callback) ==# type(function('tr')) ? Callback : function(Callback)
             if Callback({'path': self, 'nerdtree': a:nerdtree})
                 return 1
             endif
@@ -524,12 +524,12 @@ endfunction
 " returns true if this path matches the given ignore pattern
 function! s:Path._ignorePatternMatches(pattern)
     let pat = a:pattern
-    if strpart(pat,len(pat)-7) == '[[dir]]'
+    if strpart(pat,len(pat)-7) ==# '[[dir]]'
         if !self.isDirectory
             return 0
         endif
         let pat = strpart(pat,0, len(pat)-7)
-    elseif strpart(pat,len(pat)-8) == '[[file]]'
+    elseif strpart(pat,len(pat)-8) ==# '[[file]]'
         if self.isDirectory
             return 0
         endif
@@ -550,19 +550,19 @@ function! s:Path.isAncestor(path)
 
     let this = self.str()
     let that = a:path.str()
-    return stridx(that, this) == 0
+    return stridx(that, this) ==# 0
 endfunction
 
 " FUNCTION: Path.isUnder(path) {{{1
 " return 1 if this path is somewhere under the given path in the filesystem.
 function! s:Path.isUnder(path)
-    if a:path.isDirectory == 0
+    if a:path.isDirectory ==# 0
         return 0
     endif
 
     let this = self.str()
     let that = a:path.str()
-    return stridx(this, that . s:Path.Slash()) == 0
+    return stridx(this, that . s:Path.Slash()) ==# 0
 endfunction
 
 " FUNCTION: Path.JoinPathStrings(...) {{{1
@@ -665,7 +665,7 @@ function! s:Path.readInfoFromDisk(fullpath)
     let hardPath = s:Path.Resolve(self.strTrunk()) . '/' . lastPathComponent
 
     "if  the last part of the path is a symlink then flag it as such
-    let self.isSymLink = (s:Path.Resolve(hardPath) != hardPath)
+    let self.isSymLink = (s:Path.Resolve(hardPath) !=# hardPath)
     if self.isSymLink
         let self.symLinkDest = s:Path.Resolve(fullpath)
 
@@ -706,7 +706,7 @@ function! s:Path.rename(newPath)
     call s:Path.createParentDirectories(a:newPath)
 
     let success =  rename(self.str(), a:newPath)
-    if success != 0
+    if success !=# 0
         throw "NERDTree.PathRenameError: Could not rename: '" . self.str() . "'" . 'to:' . a:newPath
     endif
     call self.readInfoFromDisk(a:newPath)
@@ -779,7 +779,7 @@ endfunction
 " FUNCTION: Path._strForUI() {{{1
 function! s:Path._strForUI()
     let toReturn = '/' . join(self.pathSegments, '/')
-    if self.isDirectory && toReturn != '/'
+    if self.isDirectory && toReturn !=# '/'
         let toReturn  = toReturn . '/'
     endif
     return toReturn
@@ -802,7 +802,7 @@ function! s:Path._strForEdit()
 
     " On Windows, the drive letter may be removed by "fnamemodify()".  Add it
     " back, if necessary.
-    if nerdtree#runningWindows() && l:result[0] == s:Path.Slash()
+    if nerdtree#runningWindows() && l:result[0] ==# s:Path.Slash()
         let l:result = self.drive . l:result
     endif
 
diff --git a/lib/nerdtree/tree_dir_node.vim b/lib/nerdtree/tree_dir_node.vim
index f59c064..1502ea7 100644
--- a/lib/nerdtree/tree_dir_node.vim
+++ b/lib/nerdtree/tree_dir_node.vim
@@ -14,7 +14,7 @@ let g:NERDTreeDirNode = s:TreeDirNode
 " Class method that returns the highest cached ancestor of the current root.
 function! s:TreeDirNode.AbsoluteTreeRoot()
     let currentNode = b:NERDTree.root
-    while currentNode.parent != {}
+    while currentNode.parent !=# {}
         let currentNode = currentNode.parent
     endwhile
     return currentNode
@@ -100,7 +100,7 @@ function! s:TreeDirNode.displayString()
     let l:cascade = self.getCascade()
     for l:dirNode in l:cascade
         let l:next = l:dirNode.path.displayString()
-        let l:label .= l:label == '' ? l:next : substitute(l:next,'^.','','')
+        let l:label .= l:label ==# '' ? l:next : substitute(l:next,'^.','','')
     endfor
 
     " Select the appropriate open/closed status indicator symbol.
@@ -133,7 +133,7 @@ function! s:TreeDirNode.findNode(path)
     if self.path.isDirectory
         for i in self.children
             let retVal = i.findNode(a:path)
-            if retVal != {}
+            if retVal !=# {}
                 return retVal
             endif
         endfor
@@ -169,7 +169,7 @@ function! s:TreeDirNode.getCascadeRoot()
 
     while !empty(l:parent) && !l:parent.isRoot()
 
-        if index(l:parent.getCascade(), self) == -1
+        if index(l:parent.getCascade(), self) ==# -1
             break
         endif
 
@@ -258,7 +258,7 @@ endfunction
 " Return a list of all child nodes from 'self.children' that are of type
 " TreeDirNode. This function supports http://github.com/scrooloose/nerdtree-project-plugin.git.
 function! s:TreeDirNode.getDirChildren()
-    return filter(copy(self.children), 'v:val.path.isDirectory == 1')
+    return filter(copy(self.children), 'v:val.path.isDirectory ==# 1')
 endfunction
 
 " FUNCTION: TreeDirNode._glob(pattern, all) {{{1
@@ -278,13 +278,13 @@ function! s:TreeDirNode._glob(pattern, all)
 
     " Construct a path specification such that globpath() will return
     " relative pathnames, if possible.
-    if self.path.str() == getcwd()
+    if self.path.str() ==# getcwd()
         let l:pathSpec = ','
     else
         let l:pathSpec = escape(fnamemodify(self.path.str({'format': 'Glob'}), ':.'), ',')
 
         " On Windows, the drive letter may be removed by fnamemodify().
-        if nerdtree#runningWindows() && l:pathSpec[0] == g:NERDTreePath.Slash()
+        if nerdtree#runningWindows() && l:pathSpec[0] ==# g:NERDTreePath.Slash()
             let l:pathSpec = self.path.drive . l:pathSpec
         endif
     endif
@@ -293,11 +293,11 @@ function! s:TreeDirNode._glob(pattern, all)
 
     " See ':h version7.txt' and ':h version8.txt' for details on the
     " development of the glob() and globpath() functions.
-    if v:version > 704 || (v:version == 704 && has('patch654'))
+    if v:version > 704 || (v:version ==# 704 && has('patch654'))
         let l:globList = globpath(l:pathSpec, a:pattern, !g:NERDTreeRespectWildIgnore, 1, 0)
-    elseif v:version == 704 && has('patch279')
+    elseif v:version ==# 704 && has('patch279')
         let l:globList = globpath(l:pathSpec, a:pattern, !g:NERDTreeRespectWildIgnore, 1)
-    elseif v:version > 702 || (v:version == 702 && has('patch051'))
+    elseif v:version > 702 || (v:version ==# 702 && has('patch051'))
         let l:globString = globpath(l:pathSpec, a:pattern, !g:NERDTreeRespectWildIgnore)
         let l:globList = split(l:globString, "\n")
     else
@@ -315,13 +315,13 @@ function! s:TreeDirNode._glob(pattern, all)
             " If l:file has a trailing slash, then its :tail will be ''. Use
             " :h to drop the slash and the empty string after it; then use :t
             " to get the directory name.
-            if l:tail == ''
+            if l:tail ==# ''
                 let l:tail = fnamemodify(l:file, ':h:t')
             endif
 
-            if l:tail == '.' || l:tail == '..'
+            if l:tail ==# '.' || l:tail ==# '..'
                 call add(l:toRemove, l:file)
-                if len(l:toRemove) == 2
+                if len(l:toRemove) ==# 2
                     break
                 endif
             endif
@@ -341,7 +341,7 @@ endfunction
 unlet s:TreeDirNode.GetSelected
 function! s:TreeDirNode.GetSelected()
     let currentDir = g:NERDTreeFileNode.GetSelected()
-    if currentDir != {} && !currentDir.isRoot()
+    if currentDir !=# {} && !currentDir.isRoot()
         if currentDir.path.isDirectory ==# 0
             let currentDir = currentDir.parent
         endif
@@ -373,7 +373,7 @@ endfunction
 " FUNCTION: TreeDirNode.hasVisibleChildren() {{{1
 " returns 1 if this node has any childre, 0 otherwise..
 function! s:TreeDirNode.hasVisibleChildren()
-    return self.getVisibleChildCount() != 0
+    return self.getVisibleChildCount() !=# 0
 endfunction
 
 " FUNCTION: TreeDirNode.isCascadable() {{{1
@@ -383,7 +383,7 @@ endfunction
 "  2. If the parent is a symlink or is bookmarked, you end up with unparsable
 "     text, and NERDTree cannot get the path of any child node.
 function! s:TreeDirNode.isCascadable()
-    if g:NERDTreeCascadeSingleChildDir == 0
+    if g:NERDTreeCascadeSingleChildDir ==# 0
         return 0
     endif
 
@@ -398,7 +398,7 @@ function! s:TreeDirNode.isCascadable()
     endfor
 
     let c = self.getVisibleChildren()
-    return len(c) == 1 && c[0].path.isDirectory
+    return len(c) ==# 1 && c[0].path.isDirectory
 endfunction
 
 " FUNCTION: TreeDirNode._initChildren() {{{1
@@ -447,7 +447,7 @@ endfunction
 " path: dir that the node represents
 " nerdtree: the tree the node belongs to
 function! s:TreeDirNode.New(path, nerdtree)
-    if a:path.isDirectory != 1
+    if a:path.isDirectory !=# 1
         throw 'NERDTree.InvalidArgumentsError: A TreeDirNode object must be instantiated with a directory Path object.'
     endif
 
@@ -510,7 +510,7 @@ function! s:TreeDirNode.openAlong(...)
     while node.path.isDirectory
         call node.open(opts)
         let level += 1
-        if node.getVisibleChildCount() == 1
+        if node.getVisibleChildCount() ==# 1
             let node = node.getChildByIndex(0, 1)
         else
             break
@@ -567,7 +567,7 @@ function! s:TreeDirNode.refresh()
                 "create a new path and see if it exists in this nodes children
                 let path = g:NERDTreePath.New(i)
                 let newNode = self.getChild(path)
-                if newNode != {}
+                if newNode !=# {}
                     call newNode.refresh()
                     call add(newChildNodes, newNode)
 
@@ -622,7 +622,7 @@ function! s:TreeDirNode.reveal(path, ...)
     if self.path.equals(a:path.getParent())
         let n = self.findNode(a:path)
         " We may be looking for a newly-saved file that isn't in the tree yet.
-        if n == {}
+        if n ==# {}
             call self.refresh()
             let n = self.findNode(a:path)
         endif
@@ -676,7 +676,7 @@ function! s:TreeDirNode.toggleOpen(...)
     if self.isOpen ==# 1
         call self.close()
     else
-        if g:NERDTreeCascadeOpenSingleChildDir == 0
+        if g:NERDTreeCascadeOpenSingleChildDir ==# 0
             call self.open(opts)
         else
             call self.openAlong(opts)
diff --git a/lib/nerdtree/ui.vim b/lib/nerdtree/ui.vim
index 6dc0d21..fc9db71 100644
--- a/lib/nerdtree/ui.vim
+++ b/lib/nerdtree/ui.vim
@@ -157,7 +157,7 @@ function! s:UI.getPath(ln)
 
     let rootLine = self.getRootLineNum()
 
-    if a:ln == rootLine
+    if a:ln ==# rootLine
         return self.nerdtree.root.path
     endif
 
@@ -182,7 +182,7 @@ function! s:UI.getPath(ln)
         let curLineStripped = self._stripMarkup(curLine)
 
         " have we reached the top of the tree?
-        if lnum == rootLine
+        if lnum ==# rootLine
             let dir = self.nerdtree.root.path.str({'format': 'UI'}) . dir
             break
         endif
@@ -219,7 +219,7 @@ function! s:UI.getLineNum(node)
         let l:currentLine = getline(l:lineNumber)
         let l:indentLevel = self._indentLevelFor(l:currentLine)
 
-        if l:indentLevel != l:currentPathComponent
+        if l:indentLevel !=# l:currentPathComponent
             continue
         endif
 
@@ -229,7 +229,7 @@ function! s:UI.getLineNum(node)
         " Directories: If the current path 'starts with' the full path, then
         " either the paths are equal or the line is a cascade containing the
         " full path.
-        if l:fullPath[-1:] == '/' && stridx(l:currentPath, l:fullPath) == 0
+        if l:fullPath[-1:] ==# '/' && stridx(l:currentPath, l:fullPath) ==# 0
             return l:lineNumber
         endif
 
@@ -240,7 +240,7 @@ function! s:UI.getLineNum(node)
 
         " Otherwise: If the full path starts with the current path and the
         " current path is a directory, we add a new path component.
-        if stridx(l:fullPath, l:currentPath) == 0 && l:currentPath[-1:] == '/'
+        if stridx(l:fullPath, l:currentPath) ==# 0 && l:currentPath[-1:] ==# '/'
             let l:currentLine = substitute(l:currentLine, '/\s*$', '', '')
             call add(l:pathComponents, l:currentLine)
             let l:currentPathComponent += 1
@@ -296,7 +296,7 @@ endfunction
 
 " FUNCTION: s:UI.isIgnoreFilterEnabled() {{{1
 function! s:UI.isIgnoreFilterEnabled()
-    return self._ignoreEnabled == 1
+    return self._ignoreEnabled ==# 1
 endfunction
 
 " FUNCTION: s:UI.isMinimal() {{{1
@@ -317,7 +317,7 @@ function! s:UI._renderBookmarks()
         call cursor(line('.')+1, col('.'))
     endif
 
-    if g:NERDTreeBookmarksSort == 1 || g:NERDTreeBookmarksSort == 2
+    if g:NERDTreeBookmarksSort ==# 1 || g:NERDTreeBookmarksSort ==# 2
         call g:NERDTreeBookmark.SortBookmarksList()
     endif
 
@@ -443,13 +443,13 @@ function! s:UI.renderViewSavingPosition()
 
     " go up the tree till we find a node that will be visible or till we run
     " out of nodes
-    while currentNode != {} && !currentNode.isVisible() && !currentNode.isRoot()
+    while currentNode !=# {} && !currentNode.isVisible() && !currentNode.isRoot()
         let currentNode = currentNode.parent
     endwhile
 
     call self.render()
 
-    if currentNode != {}
+    if currentNode !=# {}
         call currentNode.putCursorHere(0, 0)
     endif
 endfunction
diff --git a/nerdtree_plugin/exec_menuitem.vim b/nerdtree_plugin/exec_menuitem.vim
index 20083e0..fb6c486 100644
--- a/nerdtree_plugin/exec_menuitem.vim
+++ b/nerdtree_plugin/exec_menuitem.vim
@@ -32,7 +32,7 @@ function! NERDTreeExecFile()
     let cmd = treenode.path.str({'escape': 1})
     let cmd = input(':!', cmd . ' ')
 
-    if cmd != ''
+    if cmd !=# ''
         exec ':!' . cmd
     else
         echo 'Aborted'
diff --git a/nerdtree_plugin/fs_menu.vim b/nerdtree_plugin/fs_menu.vim
index b2eda5a..3ecfa81 100644
--- a/nerdtree_plugin/fs_menu.vim
+++ b/nerdtree_plugin/fs_menu.vim
@@ -51,27 +51,27 @@ endif
 "Args:
 "action: the action that is being performed, e.g. 'delete'
 function! s:inputPrompt(action)
-    if a:action == 'add'
+    if a:action ==# 'add'
         let title = 'Add a childnode'
         let info = "Enter the dir/file name to be created. Dirs end with a '/'"
         let minimal = 'Add node:'
 
-    elseif a:action == 'copy'
+    elseif a:action ==# 'copy'
         let title = 'Copy the current node'
         let info = 'Enter the new path to copy the node to:'
         let minimal = 'Copy to:'
 
-    elseif a:action == 'delete'
+    elseif a:action ==# 'delete'
         let title = 'Delete the current node'
         let info = 'Are you sure you wish to delete the node:'
         let minimal = 'Delete?'
 
-    elseif a:action == 'deleteNonEmpty'
+    elseif a:action ==# 'deleteNonEmpty'
         let title = 'Delete the current node'
         let info =  "STOP! Directory is not empty! To delete, type 'yes'"
         let minimal = 'Delete directory?'
 
-    elseif a:action == 'move'
+    elseif a:action ==# 'move'
         let title = 'Rename the current node'
         let info = 'Enter the new path for the node:'
         let minimal = 'Move to:'
@@ -114,9 +114,9 @@ function! s:promptToDelBuffer(bufnum, msg)
             let l:listedBufferCount = 0
         endif
         if l:listedBufferCount > 1
-            call nerdtree#exec('tabdo windo if winbufnr(0) == ' . a:bufnum . " | exec ':bnext! ' | endif", 1)
+            call nerdtree#exec('tabdo windo if winbufnr(0) ==# ' . a:bufnum . " | exec ':bnext! ' | endif", 1)
         else
-            call nerdtree#exec('tabdo windo if winbufnr(0) == ' . a:bufnum . " | exec ':enew! ' | endif", 1)
+            call nerdtree#exec('tabdo windo if winbufnr(0) ==# ' . a:bufnum . " | exec ':enew! ' | endif", 1)
         endif
         call nerdtree#exec('tabnext ' . s:originalTabNumber, 1)
         call nerdtree#exec(s:originalWindowNumber . 'wincmd w', 1)
@@ -146,7 +146,7 @@ function! s:renameBuffer(bufNum, newNodeName, isDirectory)
     " display a buffer for a new filename.
     let s:originalTabNumber = tabpagenr()
     let s:originalWindowNumber = winnr()
-    call nerdtree#exec('tabdo windo if winbufnr(0) == ' . a:bufNum . " | exec ':e! " . editStr . "' | endif", 1)
+    call nerdtree#exec('tabdo windo if winbufnr(0) ==# ' . a:bufNum . " | exec ':e! " . editStr . "' | endif", 1)
     call nerdtree#exec('tabnext ' . s:originalTabNumber, 1)
     call nerdtree#exec(s:originalWindowNumber . 'wincmd w', 1)
     " 3. We don't need a previous buffer anymore
@@ -330,7 +330,7 @@ function! NERDTreeCopyNode()
     let prompt = s:inputPrompt('copy')
     let newNodePath = input(prompt, currentNode.path.str(), 'file')
 
-    if newNodePath != ''
+    if newNodePath !=# ''
         "strip trailing slash
         let newNodePath = substitute(newNodePath, '\/$', '', '')
 
@@ -369,7 +369,7 @@ endfunction
 function! NERDTreeCopyPath()
     let l:nodePath = g:NERDTreeFileNode.GetSelected().path.str()
     if has('clipboard')
-        if &clipboard == 'unnamedplus'
+        if &clipboard ==# 'unnamedplus'
             let @+ = l:nodePath
         else
             let @* = l:nodePath
@@ -383,7 +383,7 @@ endfunction
 " FUNCTION: NERDTreeQuickLook() {{{1
 function! NERDTreeQuickLook()
     let treenode = g:NERDTreeFileNode.GetSelected()
-    if treenode != {}
+    if treenode !=# {}
         call system("qlmanage -p 2>/dev/null '" . treenode.path.str() . "'")
     endif
 endfunction
@@ -391,7 +391,7 @@ endfunction
 " FUNCTION: NERDTreeRevealInFinder() {{{1
 function! NERDTreeRevealInFinder()
     let treenode = g:NERDTreeFileNode.GetSelected()
-    if treenode != {}
+    if treenode !=# {}
         call system("open -R '" . treenode.path.str() . "'")
     endif
 endfunction
@@ -399,7 +399,7 @@ endfunction
 " FUNCTION: NERDTreeExecuteFile() {{{1
 function! NERDTreeExecuteFile()
     let treenode = g:NERDTreeFileNode.GetSelected()
-    if treenode != {}
+    if treenode !=# {}
         call system("open '" . treenode.path.str() . "'")
     endif
 endfunction
@@ -408,7 +408,7 @@ endfunction
 function! NERDTreeRevealFileLinux()
     let treenode = g:NERDTreeFileNode.GetSelected()
     let parentnode = treenode.parent
-    if parentnode != {}
+    if parentnode !=# {}
         call system("xdg-open '" . parentnode.path.str() . "' &")
     endif
 endfunction
@@ -416,7 +416,7 @@ endfunction
 " FUNCTION: NERDTreeExecuteFileLinux() {{{1
 function! NERDTreeExecuteFileLinux()
     let treenode = g:NERDTreeFileNode.GetSelected()
-    if treenode != {}
+    if treenode !=# {}
         call system("xdg-open '" . treenode.path.str() . "' &")
     endif
 endfunction
diff --git a/nerdtree_plugin/vcs.vim b/nerdtree_plugin/vcs.vim
index 29de1e7..36d5427 100644
--- a/nerdtree_plugin/vcs.vim
+++ b/nerdtree_plugin/vcs.vim
@@ -34,7 +34,7 @@ endfunction
 function! s:FindParentVCSRoot(path)
     let l:path = a:path
     while !empty(l:path) &&
-        \ l:path._str() !~ '^\(\a:\\\|\/\)$' &&
+        \ l:path._str() !~# '^\(\a:\\\|\/\)$' &&
         \ !isdirectory(l:path._str() . '/.git') &&
         \ !isdirectory(l:path._str() . '/.svn') &&
         \ !isdirectory(l:path._str() . '/.hg') &&
@@ -42,6 +42,6 @@ function! s:FindParentVCSRoot(path)
         \ !isdirectory(l:path._str() . '/_darcs')
         let l:path = l:path.getParent()
     endwhile
-    return (empty(l:path) || l:path._str() =~ '^\(\a:\\\|\/\)$') ? a:path : l:path
+    return (empty(l:path) || l:path._str() =~# '^\(\a:\\\|\/\)$') ? a:path : l:path
 endfunction
 
diff --git a/plugin/NERD_tree.vim b/plugin/NERD_tree.vim
index 8264efa..9b4df5d 100644
--- a/plugin/NERD_tree.vim
+++ b/plugin/NERD_tree.vim
@@ -91,7 +91,7 @@ call s:initVariable('g:NERDTreeGlyphReadOnly', 'RO')
 
 if has('conceal')
     call s:initVariable('g:NERDTreeNodeDelimiter', "\x07")
-elseif (g:NERDTreeDirArrowExpandable == "\u00a0" || g:NERDTreeDirArrowCollapsible == "\u00a0")
+elseif (g:NERDTreeDirArrowExpandable ==# "\u00a0" || g:NERDTreeDirArrowCollapsible ==# "\u00a0")
     call s:initVariable('g:NERDTreeNodeDelimiter', "\u00b7")
 else
     call s:initVariable('g:NERDTreeNodeDelimiter', "\u00a0")
@@ -184,7 +184,7 @@ if g:NERDTreeHijackNetrw
     augroup END
 endif
 
-if g:NERDTreeChDirMode == 3
+if g:NERDTreeChDirMode ==# 3
     augroup NERDTreeChDirOnTabSwitch
         autocmd TabEnter * if g:NERDTree.ExistsForTab()|call g:NERDTree.ForCurrentTab().getRoot().path.changeToDir()|endif
     augroup END