ESM Support

[nathan-knight]

This resolves #248

Checklist

• npm test passes and has 100% coverage
• README.md is updated

These changes allow migrate-mongo to work in projects with "type": "module" set in their package.json file without disrupting other configurations or requiring additional configuration.

Config files should use export default { instead of module.exports = {
Migrations should look like:

export const up = async (db, client)  => { ... }
export const down = async (db, client)  => { ... }

[coveralls]

Coverage remained the same at 100.0% when pulling 216d086 on nathan-knight:esm-support into 4906ff2 on seppevs:master.

[ghost]

This feature looks interesting. Could you add tests please :) ?

[nathan-knight]

This feature looks interesting. Could you please add tests please :) ?

I added some tests and fixed some existing tests that did not work on Windows.

[ghost]

This feature looks interesting. Could you please add tests please :) ?

I added some tests and fixed some existing tests that did not work on Windows.

Nice !

[lattam]

Great work! When do think this could be merged and released?
Thank you

[ghost]

@nathan-knight
I observe instability here (potentially depending on the Node version used ???)
This code used to work for me, I used it some weeks ago but now for the same usage I no longer have this error code thrown by the Node's require so it seems unstable.

[nathan-knight]

This error only occurs on newer versions of Node that are configured to use ES modules

[boycce]

Nice, when will this be released?

[nathan-knight]

Nice, when will this be released?

I'm available to make any remaining changes that are required. It just needs someone with write access to merge the PR if it is good to go.

[nuno-ferrao]

Any idea when this update will be released? Would be very useful to me :)

[joezappie]

I too am looking to use this but have type: "module" so I can use import in my project. This is breaking this tool as node complains:

RROR: Must use import to load ES Module: C:...\migrate-mongo-config.js
require() of ES modules is not supported.

[nathan-knight]

@seppevs Are there any other changes that are needed for this to be merged?

[joshhansen]

Just ran into this issue... looks like a ready-made solution...? This would let me adopt migrate-mongo, which I'd love to be able to do!

[ksmithut]

As a workaround, I was able to get it to work by having my migration files still be in common js with the .cjs extensions, then set the migrationFileExtension option in my config file to '.cjs'. Not a great solution since it seems like it's so close to getting merged in, but my migration files aren't terrible big, and wouldn't be a bit deal to migrate the files once this gets fixed.

[MattG561]

Any update on the release date for this? This PR has been open since May...

[seppevs]

Thank you for your contribution, and sorry it took so long. I have merged your PR to the master branch, and improved the ESM support a bit further. This feature has finally landed in migrate-mongo 9.0.0!