Prefer capability sniffing to environment check?

[glebec]

As per #160, it is technically possible to run code with the environment set to test even if the code isn't actually being run by Mocha. This causes a reference error for code which attempts to use after.

While that isn't the way the codebase is intended to be used, one possible way of making the code more robust is to use capability sniffing:

-if (process.env.NODE_ENV === 'test') {
+if (typeof global.after === 'function') {
   after(...)
}

I'm not 100% sure I prefer this – it is safer, but perhaps less clear.

[collin]

Maybe name it as a utility?

function processIsRunningInMochaTestRunner () {
  // Some nice prose description of feature detection
  return typeof global.after === 'function'
}

if (processIsRunningInMochaTestRunner()) {
  after(/* ... */)
}

[glebec]

Maybe. If we switched to e.g. Jest we would just change the name of the function, which isn't so onerous because for example Jest uses afterAll – so we'd have to change some code anyway. And I like the centralization this might yield, if we share the function in the multiple places we register after hooks.

[glebec]

Or perhaps we should be creating a resource cleanup service?

const resourceManager = require('../utils/resourceManager')

...

resourceManager.onComplete(() => db.close())

Then inside the manager, we would use the check:

if (typeof global.after === 'function') {
    after(() => manager.runCleanupHooks())
}

…something like that. This might be an unnecessary level of abstraction though… thinking about it.