为什么 Instagram API 会为同一个用户返回两个不同的 user_id 值？

Question

Nutshell: PHP implementation gets correct user_id, React.js implementation gets incorrect user_id. Why??

I implemented the Instagram Basic Display API OAuth flow in PHP and in Javascript under React.

The flow under PHP works fine - I get a code, I POST it using curl to /oauth/access_token , I receive a client_id and an access_token , all fine, subsequent Graph API requests work just fine.

Then I moved to rebuild it in Javascript. Here, when I get a code, and I POST it using fetch to /oauth/access_token , with the same client_id and client_secret , and the same authenticating user, essentially the same request, just a different redirect URL (obviously), I receive a token and a different user_id , one that does not work (it gets a 400 error from Graph API).

Oddly enough, the bad user_id is consistently smaller by 1 than the one that I get with PHP: the good one ends with 93, the bad one ends with 92. If I do the unspeakable and just manually increase the wrong user_id I received, I obtain a valid user_id for which the token works!

So why is Instagram sending me a wrong user_id, and how can I help it?

Answer 1

I finally found the cause, moments ago, after writing the question and earlier wasting 5 hours on analyzing whatever I could think of.

The user_id is sent as a number larger than Number.MAX_SAFE_INTEGER, and thus JSON.parse fails to parse it correctly . Instagram should be encoding the user_id field as a string. This API endpoint thus needs to be parsed manually. I "fixed" mine by filtering the results as such: text = text.replace(/"user_id":\s*(\d+)/,'"user_id":"$1"') . Still, encoding such large numbers as "numbers" in JSON is a horrible practice and Instagram should fix their API instead.