feat(publish): add --summary-file option

[HamishBuckmaster]

Outputs the packages and versions from publishing to a JSON file.

Description

When lerna publish --summary-file <path-to-file> It'll create a file to easily see what's been published and what version has been.
Happy to rename --summary-file to something more meaningful

[
    {
        "packageName": "package1",
        "version": "v1.0.1-alpha"
    },
    {
        "packageName": "package2",
        "version": "v2.0.1-alpha"
    }
]

Motivation and Context

When creating a release you don't get a definitive and easy way to see whats changed in a nice output especially if its a pre-release(canary), So added the ability to output a JSON object to a file which would look something like this.
#2053

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[mariusGundersen]

This would be really useful in CI where it could be used for checking what will happen when a pull-request is merged

[HamishBuckmaster]

Hey @evocateur,

Is there anything else that needs to be done here? 😄

[g5bot]

@HamishBuckmaster there are tests failing, see travis-ci

[HamishBuckmaster]

@HamishBuckmaster there are tests failing, see travis-ci

It's passing now, @g5bot. 😋
@evocateur what are the next steps to get this merged now?

[carl0s-sa]

Eager for this feature, any plans on merging?

[isachivka]

Merge it please

[HamishBuckmaster]

Hi @evocateur / @gigabo,

All these tests are passing on local, can you provide any advice as to why they are failing?

[zepang]

When will this feature be supported ?

[marcus13371337]

I would also have good use for this functionality!

[eddysims]

I also have good use for this!

[mnahkies]

I'd love to see this merged. My use case is that I'd like my CI pipeline to add a comment to the originating pull request with the relevant versions / yarn add commands, so that we can grab them from github rather than digging into the CI logs.

It's a minor inconvenience to have to drop into the CI logs, but still inconvenient.

I could probably capture the existing raw output and parse/dump that onto a comment, but a JSON file would be a lot cleaner to process.

[asafkorem]

I'd be happy to have this feature as well! 🙂

[HamishBuckmaster]

@JamesHenry / @vsavkin are you happy with the above approach, would like to get this merged once and for all 👍

[JamesHenry]

Thank you @HamishBuckmaster I can see that this would be a useful feature!

Please kindly check out the comments I left inline, and also please update the lerna-schema.json to include this new option

[JamesHenry]

Hi @HamishBuckmaster do you have time to continue working on this?

[HamishBuckmaster]

Hi @HamishBuckmaster do you have time to continue working on this?

Yes! @JamesHenry, will have a look when I get a chance

[JamesHenry]

@HamishBuckmaster I think we are just down to a formatting issue now

[JamesHenry]

Thanks so much again for your patience and work on this @HamishBuckmaster!

[HamishBuckmaster]

Thanks so much again for your patience and work on this @HamishBuckmaster!

Thanks for your patience @JamesHenry