feat: add json schema for lerna.json

[fahslaj]

Adds a json schema for lerna.json.

Motivation and Context

This change improves the developer experience of Lerna. Now, when modifying lerna.json, users can see what properties are valid and a brief description of what they do (taken from the lerna command options documentation).

Note: All options for commands (as described in the command docs) are valid configuration options in lerna.json. They can be provided at three levels, in order of priority:

1. Command line inline option
2. lerna.json, under a specific command
3. Top level of lerna.json

The json schema for lerna.json supports supplying options at both level 2 and 3 above.

How Has This Been Tested?

I tested the schema by changing lerna.json in this repo and observing (in my editor) the metadata from the schema. I did not manually test every configuration option for every command. I obtained the metadata from the configuration code for each of the Lerna commands (command.js), with some input from the docs.

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)
• Chore (change that has absolutely no effect on users)

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.

[ThisIsMissEm]

I might be wrong, but I think you'd also want the schema to be published as part of the lerna website somehow, such that it can be referred to via uri instead of relative file path.

[JamesHenry]

@fahslaj The source for this should be within the lerna package so that it is published and can be referenced by other workspaces not just the lerna repo itself. I had already done that on the initial branch: main...lerna-json-schema

Please also add the reference to the schema as part of lerna create as I had done on that branch.

NOTE: one thing I hadn't yet done on there was update the files array in the lerna package's package.json, you will need to do that as well please

[JamesHenry]

Ok there are so many newlines, I'm guessing they are actually not random? 😅

[fahslaj]

Ok there are so many newlines, I'm guessing they are actually not random? 😅

Yes, they are not random. I put a new line between the filter options, global options, and command specific options to make it slightly more readable.

[JamesHenry]

Ok there are so many newlines, I'm guessing they are actually not random? 😅

Yes, they are not random. I put a new line between the filter options, global options, and command specific options to make it slightly more readable.

Ah ok fair enough, shame we can't force it to stay like that over time, but then again hopefully this shouldn't need too many major updates anyway!

[fahslaj]

I have moved the lerna-schema.json inside of core/lerna. It will now be published with the lerna package. Running lerna init will generate lerna.json with the correct schema reference to node_modules/.../lerna-schema.json. End users with existing lerna workspaces will need to add the schema reference themselves.