Fix changes introduced in https://github.com/request/request/pull/1282

[simov]

Fixes #1309

Reverting back the changes introduced in #1282 more info here #1281

For some reason this change brakes the form option when it's object. See below

From the docs

form - when passed an object or a querystring, this sets body to a querystring representation of value, and adds Content-type: application/x-www-form-urlencoded header.

No idea why it brakes yet, that's just the fix. I can confirm the bug by running my system tests in https://github.com/simov/purest/blob/master/test/request/post.js

[simov]

This is very bad, it turns out that the unit test doesn't catch the bug.

[coveralls]

Coverage decreased (-0.09%) when pulling f9f96e6 on simov:fix-form-option into 67b4b1a on request:master.

[simov]

The problem is that here body is set to a string, and self.form is called before self.json is called and therefore here we're stringifying the body string again.

In short with the current implementation we can support only non string JSON bodies

if (typeof self.body !== 'string')

but that's just too magical.

And of course we need a proper unit test for that combination of options before making any changes to that behavior.

[simov]

Added the missing test case. Now changing if (typeof self.body === 'object') to if (self.body !== undefined) on line https://github.com/simov/request/blob/fix-form-option/request.js#L1485 would throw an error. So #1282 wouldn't even pass.

[simov]

@nylen pushed a fix, also re-enabled the tests for #1282
I think this is really urgent to merge and publish, as more bug reports will definitely arrive.

EDIT: I can confirm this fixes the problem in my module as well.

[nylen]

I have not been following this issue very closely, so thank you for the support!

Version 2.51.0 is out now with this fix.