JavaScript Function Editor
built with lite-code-editor

const ts0 = new Date const obj = { ts0, self: this} console.log( 'In edited JSY func before await', obj ) await new Promise( y => setTimeout(y, 1000) ) const ts1 = obj.ts1 = new Date() obj.td = ts1 - ts0 console.log('In edited JSY func after await', obj) return obj

and then use the web developer console for output!

Find more about lite-code-editor in this demo, on github, or on npmjs.
Also take a look at js-func-editor and the JSY transpiling jsy-func-editor.