e2e test the public GET API

[0xCLARITY]

High Level Overview of Change

• Add new launch.json configuration to allow VSCode Node debug breakpoints to be triggered when you run a single Mocha test file or run all tests. Super helpful for debugging why a test you thought should work is not.
• Add two new "golden path" tests for the public GET API. Kind of hacky in that it uses a "payment pointer" of 127.0.0.1, but if this works on CI, I'm all for it.

Context of Change

I was struggling with how to do an E2E test of the public GET API, since in reality, it will only get requests forwarded from some other place.

Like if our PayID service is at payid.xpring.io, there won't be any payment pointers under that domain. They will all be xpring.money/{username}, which gets redirected to payid.xpring.io.

But, if I hit the public GET API from a Mocha test, it assumes a "domain" of 127.0.0.1, so if CI passes on this, we can assert the E2E behavior of the public GET API!

Type of Change

• New feature (non-breaking change which adds functionality)

Before / After

Hopefully CI will now have more tests passing!

Test Plan

npm run test works here, but the real test is if this works on CI.

Future Tasks

Might be worth testing some failure scenarios (Invalid Accept Header, 404 error response payload, etc.)

[0xCLARITY]

CircleCI passes!

[dino-rodriguez]

Clean flow with supertest! No comments here. Looks simple and understandable.

[keefertaylor]

LGTM. Left some stylistic feedback that I don't feel too strongly about.

[keefertaylor]

I would re-write this as follows for clarity. Moving comments around and giving /hbergren a name since it's an important part of the world.

    // GIVEN a payment pointer known to have an associated xrpl-mainnet address
    const paymentPointer = '/hbergren' // NEW
    const expectedResponse = {
      address: 'X7gJd9k3hHMRABeqvVTgeak8dRJ6eaJFYbhRVKAci6fEomg',
      network: 'xrpl-mainnet',
    }

    // WHEN we make a GET request to the public endpoint to retrieve payment info with an Accept header specifying xrpl-mainnet
    request(app.publicAPIExpress)
      .get(paymentPointer) // CHANGED
      .set('Accept', 'application/xrpl-mainnet+json')
      // THEN we get back the XRP address and network associated with that payment pointer for xrpl-mainnet.
      .expect(200, expectedResponse, done)

[keefertaylor]

I'd apply the same pattern on this method.