Extract fetchYaml and maybe other fetch functions

[paulmelnikow]

See discussions:

• Rewrite [DynamicXml] and [DynamicYaml] badges #2487 (comment)
• Rewrite the [DynamicJson] badge; affects [gitlab dynamic-xml dynamic-yaml] #2399 (comment)

[paulmelnikow]

Should we keep this open?

The thing we could still do is delegate from _requestJson, _requestYaml, etc. to functions which can be invoked on any instance of BaseService.

[chris48s]

Aah yes. I was unsure on this. My initial thought was we could extract them to stand-alone functions. The reason I didn't do this was because inside the _requestFormat() functions we're calling this._request() and this.constructor._validate() so _requestFormat() doesn't extract so nicely outside of the class.

We could do it so that we pass in a requester function and a validator function as params, or so that we can pass an instance of BaseService as a param. Another option might be to try and do it as a mixin. I'm not really sure which of those makes the most/least sense.

Given the F-Droid badge could just extend BaseYamlService I decided to just leave it and deal with it once we've got an example where we actually need this abstraction.

[paulmelnikow]

pass an instance of BaseService as a param

That's the approach I've taken before:

shields/services/azure-devops/azure-devops-helpers.js

Line 18 in b4b29ab

async function fetch(serviceInstance, { url, qs = {}, errorMessages }) {

[paulmelnikow]

Gonna close this for now, as it is not seeming pressing.