FormData Object on IOS Safari sw worker

[stebuklas]

On IOS, service worker side, when using fetch and sending formData() it sends it as [FormData Object].

fetch(url, {
  method: 'POST',
  body: formData,
  credentials: "same-origin",
  headers: {
    'X-Requested-With':'XMLHttpRequest'
  }
})

When sending formData._blob, it send file, but there is more items appended to formData Object.

Any workaround?

[jimmywarting]

I don't know much of what's going on and can't pinpoint the problem in your or my code but i can give you some help to debug the problem.

---

The hole solution to this polyfill is that it's going to send a file in the end... and call formdata._blob() itself FormData.js#L376

Are you getting a references to native implementation or the patched fetch function when you console.log(fetch)?
the polyfill must be executed first to replace it...

---

I don't know why you get fewer items appended but you can inspect what is appended and what not by doing this:

var entries = formData.entries()
var iterator = entries.next()

while (!iterator.done) {
  console.log(iterator.value)
  entries.next()
}

Or with this:

// Logs the raw body:
new Response(formdata._blob()).text().then(console.log)

---

Calling formdata._blob() conditionally could potentially be a workaround:

fetch(url, {
  method: 'POST',
  body: formdata._blob ? formdata._blob() : formdata,
  credentials: "same-origin",
  headers: {
    'X-Requested-With':'XMLHttpRequest'
  }
})

---

Hopefully it should also set the requested content-type header to the correct value, hope we don't have the same problem as ie. (#44) - might be irrelevant

[jimmywarting]

closing b/c of no further discussion