Respect max_header_tokens option

[mxstbr]

Ref #4, thanks to @iamdustan who correctly pointed out that we should respect the max_header_tokens options of the .flowconfig.

Something like

const flowconfig = await danger.github.utils.fileContents('.flowconfig')
// TODO: Figure out how to parse .flowconfig somehow (why isn't it JSON ugh)

[kevinSuttle]

We are not proud of our custom format and plan to support a better format in the future. GitHub issue #153 tracks this.

– https://flow.org/en/docs/config/

https://github.com/facebook/flow/issues/153 :hurtrealbad:

[kevinSuttle]

https://repl.it/@kevinSuttle/Parsing-flowconfig-to-find-maxheadertokens

[mxstbr]

PR please? :angel:

[kevinSuttle]

Do you have suggestions for local testing?

[mxstbr]

Mocking the Danger method, see the existing tests: https://github.com/withspectrum/danger-plugin-flow/blob/master/src/index.test.ts

[kevinSuttle]

Yep, saw those. I haven't tested a Danger plugin before—in other words, how do I test it against a set of files as if it's a PR? Is that possible?

[mxstbr]

We don't have that kind of fancy mocking in place, I'd just check whether the requested filename is .flowconfig and return the contents of that.