Prototype for #53557

[hediet]

Prototype for #53557

Allows configurations to use extends to extend a given launch config, e.g.:

  {
	  "name": "Launch VS Code Internal",
	 // ...
  },
  {
	  "name": "Launch VS Code Internal With Observable Debugging",
	  "extends": "Launch VS Code Internal",
	  "env": {
		  "DEBUG_OBSERVABLES": "1"
	  }
  },

This would allow to cleanup the vscode launch.json a bit (also this one), but also enable more advanced configurations .

• needs more testing
• needs improved json schema descriptions

Configurations can only extend within one source (e.g. one launch.json file), but I think that is fine.

What do you think of this?

[roblourens]

I like it but how can you handle the json schema, is it even possible to validate the second config with the proper type?

[roblourens]

I think you could generate a schema which is specific to each launch.json, to say that if you have an entry that is "extends": "Launch VS Code Internal", then that is "type": "chrome", but the other required props are satisfied, etc etc

[hediet]

I think you could generate a schema which is specific to each launch.json, to say that if you have an entry that is "extends": "Launch VS Code Internal", then that is "type": "chrome", but the other required props are satisfied, etc etc

I was also thinking of this, but that sounds very tricky...
But extends is an advanced feature, I don't think json schema is really required here (though it would be nice).

[connor4312]

JSON schema has native support for $ref, I wonder if we can use that here? However that uses JSON path notation which may be awkward for our launch.json array

[hediet]

JSON schema has native support for $ref, I wonder if we can use that here?

It's tricky, because we want a schema for extended so that deepMerge(base, extended) satisfies the launch config item schema.
Unfortunately, that also depends on the concrete value of base (e.g. its type specifies what properties in extended can be configured)!

[Cyriuz]

What's the status of this? Would be an amazing feature for increasingly complex launch configs!

[hediet]

@connor4312 can we merge this and see usage? If usage increases we can add json schema support. This enables some use-cases and even deduplicates lots of code in our launch.json.

[roblourens]

I would support merging this to try it but I think before it goes to stable we should have a plan to do some kind of validation. I think it would be sad and inconsistent to have no intellisense and no validation for certain configs especially when they are the more complex ones. At the very least, if the json language service can't do it, validate it when you press F5 or something like that.

[roblourens]

ILogService?