fix bug: POST transport Insufficient rigorous judgment leads to invalid SSE transport

[o8x]

fix bug: POST transfer judgment was not strict enough, resulting in SSE transport never will be invoked

For example, the following POST based SSE request will be automatically taken over by POST transport and will not enter the SSE process

curl -N --request POST --url http://localhost:8080/query \
--data '{"query":"subscription { currentTime { unixTime timeStamp } }"}' \
-H "accept: text/event-stream" -H 'content-type: application/json' \
--verbose

Easy bug fixes, without updating documentation

I have:

• Added tests covering the bug / feature (see testing)
• Updated any relevant documentation (see docs)

[coveralls]

coverage: 74.663% (+0.008%) from 74.655%
when pulling 448da58 on o8x:master
into 7c8bc50 on 99designs:master.

[StevenACoffman]

Hey, thank you very much! By the way, many users have asked me if there's a public repository that demonstrates using HTTP SSE with GraphQL. Are you able to make one public?

[o8x]

Hey, thank you very much! By the way, many users have asked me if there's a public repository that demonstrates using HTTP SSE with GraphQL. Are you able to make one public?

@StevenACoffman
I would love to, but one issue prevented me from submitting the PR. I have submitted the details to the issue #3154

[StevenACoffman]

Thanks, finding this issue is also helpful! 😅

[StevenACoffman]

Hey, so it turns out this causes some problems with popular clients that advertise accepting text/event-stream, so I needed to revert this.