JSON Schema

A format, recognised by intent, never by plain .json files: a *.schema.json, or a JSON file whose top-level $schema names a json-schema.org dialect, makes the project a JSON Schema one. A file whose $schema names another schema (a tool's configuration) is an instance, not a schema. The schemas and the documents are JSON, the Data format's, so data-wellformed already covers one that does not parse.

A CI job works with the ecosystem when it runs check-jsonschema, ajv, the jsonschema CLI or jv.

schema-validation

CI validates the documents against their schemas: check-jsonschema --schemafile <schema> <documents> (or its pre-commit hook), ajv validate -s <schema> -d <documents> or ajv test (ajv-cli), jsonschema -i <document> <schema>, or jv <schema> <documents>.

code-formatting

prettier (--check, --list-different) or biome (biome format, biome ci, biome check without --write), with their configuration where the JavaScript profile reads it (.prettierrc, biome.json), or their defaults.

schema-declared

Every schema names its dialect ($schema) and itself ($id; id in draft-04 and before). A dialect older than 2019-09 (draft-07 and before) warns. A schema under a test directory is reported, not judged.

schema-examples

CI checks the examples that come with the schemas: ajv test -s <schema> -d 'examples/valid/*.json' --valid (and --invalid on the invalid ones), which asserts what each example is for; or a validator (check-jsonschema, ajv validate, the jsonschema CLI, jv) run on an examples (or samples, valid, invalid) directory. Warns when CI checks none.

schema-compatibility

CI diffs each schema against the main branch's with json-schema-diff (git show origin/main:<schema> > base.json, then json-schema-diff base.json <schema>), which fails when the schema has come to accept less. Warns when CI checks nothing. The language practices (coverage, platform matrix, …) have no tool for a schema and are skipped.