Added transaction helper

[cemremengu]

Addresses #5 and #26

Based on this example

[mcollina]

Can you support a double callback and promise interface?

[cemremengu]

You mean something like:

function transactionHelper (query, values, cb = null)

[mcollina]

Yes.

[mcollina]

you should return after rejecting.

[mcollina]

you should return after rjecting

[mcollina]

I think you should not return a promise if there is a callback. Just use the callback version and if there is no callback return a promise.

if (!cb) {
  return new Promise((resolve, reject) => {
    this.transact(query, values, function (err, res) {
       if (err) { return reject(err) }
      return resolve(res)
    })
  })
}

[cemremengu]

Could you please have another look?

Sorry, I lack experience with promises and callbacks. Another issue is that I am having trouble building the project since I am on windows so just using here to run the tests 😄 It's a walk in the dark.

Apologies for spamming

[mcollina]

Can you add some docs in the README as well?

[mcollina]

LGTM

[mcollina]

Can you pass a callback as well and support the dual promise/callback pattern?

[cemremengu]

I am sorry I thought over this but am still confused. What will that callback look like? How do I know the user wants a callback?Could you please give me some pointers?

[mcollina]

Here is an example (from avvio) https://github.com/mcollina/avvio/blob/9f947aa5a71db44f185dfab16fdf75709d00dcb3/plugin.js#L82

[cemremengu]

I know the last change is wrong but I am close to figuring it out 😄

[mcollina]

I know the last change is wrong but I am close to figuring it out 😄

Why you say so? Looks ok to me.

[cemremengu]

I made it but then the usage didn't make sense to me. If I am understanding correct, will it look like:

fastify.pg.transact((client, commit) => { 

const id = client.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['brianc']);
commit(null, id)

I am too used to async/await usage so I am having a hard time getting my head around this 😄

[mcollina]

It should be:

fastify.pg.transact((client, commit) => { 
  client.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['brianc'], commit);
})

or

fastify.pg.transact((client, commit) => { 
  client.query('INSERT INTO users(username) VALUES($1) RETURNING id', ['brianc'], (err, id) => {
    commit(err, id)
  });
})

[cemremengu]

Ahh ok now it makes sense! I was thinking in terms of async usage mixed together with callback usage 😄

Thank you for taking your time on this and bearing with me. I will add a test case for that as well

[mcollina]

Thank you for working on this. I wanted to add this for a long time!

[mcollina]

A couple of nits. This is good work!

[temsa]

Should this be merged now @mcollina ? :)

[mcollina]

Yes!

[cemremengu]

This concludes #5 and #26 🎉