CodeMirror插件json-lint.js无法正常工作

Question

index.haml

%script(src="https://codemirror.net/lib/codemirror.js")
%script(src="https://unpkg.com/jsonlint@1.6.3/web/jsonlint.js")
%script(src="https://codemirror.net/addon/lint/lint.js")
%script(src="https://codemirror.net/addon/lint/json-lint.js")
%link(src="https://codemirror.net/lib/codemirror.css")
%link(src="https://codemirror.net/addon/lint/lint.css")
%script(src="https://codemirror.net/mode/javascript/javascript.js")
%script(src="https://codemirror.net/mode/css/css.js")
%script(src="https://codemirror.net/")
%script(src="https://codemirror.net/")

%testarea#json

index.coffee

editor = CodeMirror.fromTextArea(document.getElementById('json'),
      lineNumbers: true
      mode: "application/json"
      lint: true
      gutters: ["CodeMirror-lint-markers"]
    )

该页面上没有显示警告。

我如何使它工作？我参考了官方文档和演示来实现了这一点。

• https://codemirror.net/doc/manual.html#addons
• https://github.com/codemirror/CodeMirror/blob/master/demo/lint.html