Lets say we have a schema like below:

enum Platform { web tv mobile } type Query { myQuery(platform: Platform!): MyResponse } 

And this is my query:

get($platform: Platform!) { myQuery(platform: $platform) {} } 

And I make a POST request like below:

POST /myendpoint { "query": "the above query stringified", "variables": { "platform": "watch" } } 

In this case, I am using an invalid variable that fails the request.
When making the above request, we are getting 200 status code with a response containing validation errors. Because watch is not a member of the Platform enum.

However, if I make the request without using variables, I'll get 400.

myQuery(platform: watch) {} 

Wanted to check if this is expected behaviour before moving on to finding implementation details and potentially attempting to raise a PR with a fix.