fix(redis): Remove empty object body from GET requests to Redis API

[sbosio]

Description

There's a bug in the request function from the shared Redis API lib file used for most of redis:... commands, where the default value for the request body is an empty object ({}). That makes all GET requests using that function to send that empty body when, according to standards, GET requests shouldn't send a body.

Here we change the default to a null value, so no body gets sent with GET requests and add an empty object body to all non-GET requests that would've inherited the previous default to avoid behavior changes.

Testing

Checkout this branch, ensure you're running Node 20.x and run yarn && yarn build. For the tests you will need access to a test app with a Redis database installed. If you don't have one at hand let me know and I can add you to one of my test apps.

There will be no behavior change on execution of the commands, only the headers sent with the request will change.

• Run the following command through your usual Heroku CLI:

DEBUG=http,http:headers heroku redis:info <redis-addon-name> -a <test-app-name>

You should see on the Redis API request debug output (GET https://api.heroku.com/redis/v0/databases/...) that the following headers are set:

accept: 'application/json'
content-length: '2'
content-type: 'application/json'

• Compare against the same command, but run through this branch's version:

DEBUG=http,http:headers ./bin/run redis:info <redis-addon-name> -a <test-app-name>

You should see on the Redis API request debug output (GET https://api.heroku.com/redis/v0/databases/...) that no content-type and content-length headers are included and the accept header is now:

accept: 'application/vnd.heroku+json; version=3'

• Repeat for other commands that make GET requests like redis:wait and redis:credentials. The same behavior should be observed.

SOC2 Compliance

GUS Work Item: W-18015751

[troycoll]

Tested all redis: commands against the environment that was giving us problems, 🟢 🟢 🟢