Update

indent/dart.vim

@@ -8,6 +8,32 @@ let b:did_indent = 1
 setlocal cindent
 setlocal cinoptions+=j1,J1
 
+setlocal indentexpr=DartIndent()
+
 let b:undo_indent = 'setl cin< cino<'
 
+if exists("*DartIndent")
+  finish
+endif
+
+function! DartIndent()
+  " Default to cindent in most cases
+  let indentTo = cindent(v:lnum)
+
+  let previousLine = getline(prevnonblank(v:lnum - 1))
+  let currentLine = getline(v:lnum)
+
+  " Don't indent after an annotation
+  if previousLine =~# '^\s*@.*$'
+    let indentTo = indent(v:lnum - 1)
+  endif
+
+  " Indent after opening List literal
+  if previousLine =~# '\[$' && !(currentLine =~# '^\s*\]')
+    let indentTo = indent(v:lnum - 1) + &shiftwidth
+  endif
+
+  return indentTo
+endfunction
+
 endif