Error: Cannot find module 'vscode'
    at Function.Module._resolveFilename (module.js:336:15)
    at Function.Module._load (module.js:286:25)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/Users/deerawan/Work/Sites/opensource/vscode-wordcount/out/test/extension.test.js:10:14)
    at Module._compile (module.js:434:26)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at /usr/local/lib/node_modules/mocha/lib/mocha.js:216:27
    at Array.forEach (native)
    at Mocha.loadFiles (/usr/local/lib/node_modules/mocha/lib/mocha.js:213:14)
    at Mocha.run (/usr/local/lib/node_modules/mocha/lib/mocha.js:453:10)
    at Object.<anonymous> (/usr/local/lib/node_modules/mocha/bin/_mocha:393:18)
    at Module._compile (module.js:434:26)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:475:10)
    at startup (node.js:118:18)
    at node.js:952:3