a8n: Validate campaign plan arguments with JSON schema
Created by: mrnugget
This changes the existing validation of campaign type arguments to use the JSON schemas we defined.
The errors it returns are in Markdown. I use the same functions to generate these errors that we use in the external services.
@sourcegraph/core-services What would be a good place to put these tiny helper functions to turn JSON schema validation errors into markdown? I copied them from here: https://sourcegraph.com/github.com/sourcegraph/sourcegraph@a5be7367ce89de5c316eae084492e014e4ad84f1/-/blob/cmd/frontend/db/external_services.go#L102-118