eval-in-tab

evalInTab(tab, args, functionBody)

Evaluates code within a tab and returns the result

Example

import { openBrowser, openTab, evalInTab } from 'puppet-strings'

async function run() {
  const browser = await openBrowser('google-chrome')
  const tab = await openTab(browser, 'http://example.com')

  const title = await evalInTab(tab, [], 'return document.title')

  const selector = 'body'
  const contents = await evalInTab(tab, [selector], `
    const [selector] = arguments
    return document.querySelector(selector).textContent
  `)
}
run()

Parameters

• tab (Tab)
• args (Array): A list of primitive values to send into the browser

Returns

• result (Promise): A primitive value returned by the browser

Details

evalInTab takes the functionBody, sends it into the browser as a string, and declares it as a function within the browser.

So, if functionBody is:

`
  const x = 1
  const y = 2
  return x + y
`

Then, the following function would be declared and run in the browser:

(function() {
  const x = 1
  const y = 2
  return x + y
})()

This allows us to pass arguments into that function.

So, if args is [1, 2] and functionBody is

const [x, y] = arguments
return x + y

Then, the following code would be run in the browser:

(function() {
  const [x, y] = arguments
  return x + y
})(1, 2)

And, the result would be 3.