SUPPORTESC-148 fix(core): stashFile no longer throws 'source.on' error when a request that uses await is passed in

[nicolemichellethomas]

This Pull Request fixes this issue

Previously, when await was used on a request that was passed to z.stashFile like so:

const x = await z.request(...);
return z.stashFile(x);

formData would throw the source.on is not a function. This PR fixes that issue.

Jira: https://zapierorg.atlassian.net/browse/SUPPORTESC-148

[xavdid]

@nicolemichellethomas thanks for this PR! I'll dig into this in earnest tomorrow (unless someone else beats me to it). In the meantime, can you link your jira card and provide a little context in the PR description? End-users don't have jira access, so being able to read the PR helps them understand changes for the code they use.

Sounds like this one fixing an issue where an error is thrown, but shouldn't be?

[nicolemichellethomas]

@xavdid You bet, sorry about that! Wasn't sure about the protocol 😅 Let me know if you have any questions or need anything else!

[eliangcs]

I confirmed it fixes the issue. I only have a suggested change on the var vs. let lining error.

The file stasher code is one of the spots that always take me a long time to understand. So really appreciate you took the time to read the code and fix it!

[nicolemichellethomas]

@eliangcs Awesome! I've committed the var -> let change you suggested :)

[eliangcs]

💯