Added support for environments with dotenv

[wesleytodd]

Closes #85.

@alendorff Want to check this out?

[maksnester]

@wesleytodd sure, I will check it today, thank you for notifying!

[maksnester]

Works fine!

But now I faced with another issue related to this warn message:

warning : if your migration returns a promise, do not call the done callback

I don't think that it's related to this PR, but I haven't seen such problems before (just because I didn't try migrate on Windows, I was previously blocked because I couldn't use .env files, so it's the first time when I tried it).

So, migration like this not working at all (pool.query is mysql2 function, accepts callback, returns promise):
For that case migrations are waiting infinitely after warning message.
module.exports.up = next => pool.query('<SOME SQL>', next);

And that failed with not readable error, I see error : [object Object] in console.
module.exports.up = next => pool.query('<SOME SQL>');

But that case works fine

module.exports.up = next => { 
  // no return for promise here
  pool.query('<SOME SQL>', next); 
}

[LinusU]

[name]?

maybe specify the default ('.env') here instead of further down as well?

[maksnester]

As for me, I think it would be nice to load default .env file from project root, even without that option, but keep --env <path> to specify custom path if needed.

[LinusU]

Yeah, I agree with that behaviour 👍 that was how I originally imagined as well, as well how db-migrate does it

[wesleytodd]

Thats actually a mistake. I meant to make a helper for this so that it wasn't a copy paste job. See the other files where it is [name]. Thanks for catching it.

[wesleytodd]

@alendorff It looks like your pool.query is returning a promise. As a preventative measure against calling the callback twice, it warns when you return a promise then call the callback. Just don't return with your arrow function, in this example cause you were using the "implicit return" feature of the arrow function.

EDIT: also of note, this is a breaking change release. So breaks are expected.

[maksnester]

@wesleytodd yes, I know that, that's why I showed examples. I just confused because of two things:

1. it worked previously, when I tested it on linux (make sense if current stable version doesn't support promises).
2. error like error : [object Object]

[wesleytodd]

Ahh, ok. Sorry for the confusion.

1. Current "stable" would be 0.x, which does not support Promises. This was added in 1.0.0-BETA-1 I think.
2. I am not sure what would cause that error. The logging in this package is not robust, it was on my list to fix but I never got around to it. So the error logging requires err to be something with a good toString. My guess is they are not doing an Error instance, but instead doing some custom "POJO" which looks like an error.

[rodgarcialima]

@wesleytodd yes, I know that, that's why I showed examples. I just confused because of two things:

1. it worked previously, when I tested it on linux (make sense if current stable version doesn't support promises).
2. error like error : [object Object]

Het @alendorff did you figure out how to solve this "if your migration returns a promise, do not call the done callback" problem?

Thank you

[maksnester]

@rodgarcialima sorry man, I have no idea what is this all about already 😄