PS C:\wamp64\www\sass> npm run gulp

> sasstest@1.0.0 gulp C:\wamp64\www\sass
> gulp

assert.js:350
    throw err;
    ^

AssertionError [ERR_ASSERTION]: Task function must be specified
    at Gulp.set [as _setTask] (C:\wamp64\www\sass\node_modules\undertaker\lib\set-task.js:10:3)
    at Gulp.task (C:\wamp64\www\sass\node_modules\undertaker\lib\task.js:13:8)
    at Object.<anonymous> (C:\wamp64\www\sass\gulpfile.js:30:6)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! sasstest@1.0.0 gulp: `gulp`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the sasstest@1.0.0 gulp script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in: