Add integration tests

[fedeci]

Currently we only test units, I was thinking about adding some high level tests to better catch issues as the one addressed in #1070.
@gustavohenke what do you think?

[gustavohenke]

That'd be awesome.

Fun fact, that's how express-validator used to have tests in the era before time, using supertest:
https://github.com/express-validator/express-validator/blob/v2.21.0/test/checkBodyTest.js

I really like the lib but the style back then was quite difficult to follow for me.
I'm sure we can do better this time around!

[fedeci]

How about fixtures/snapshots where the output is the the req obj? It would give full control over what happened during the middleware execution.

[gustavohenke]

Sounds good to me!

[danizavtz]

If you have a detailed specification on what should be done I can start integration tests.

[fedeci]

Thanks for the interest @danizavtz! I hope I am not too late, but here is a list of what integration tests should do in this case:

1. Accept an express req object as input;
2. Perform a validation chain/set of chains on the input;
3. Validate it against a predefined validationResult contained in a file along with the new update object;
4. They should be easy to write and to update;

e.g.

// input file
export default {
  body: { name: 'foo' },
  query: { }
}

// chains file
body("name").isString().isLength(10)

// out file
export const errors = []
// in this case the req object was not updated, but it may not be so
export const req = {
  body: { name: 'foo' },
  query: { }
}

Please ping me if you are still interested in this and feel free to ask any question!