Ack 2.0: JSON Schema Draft 2020-12 runtime support and model generation #186

Tracking issue for JSON Schema Draft 2020-12 support, deferred from Ack 1.7 to 2.0.

The work

Two draft pull requests, stacked: main ← #171 ← #167.

• feat(ack): support Draft 2020-12 runtime import and export #171, runtime import and export. Extends Ack.fromJsonSchema() to the complete required Draft 2020-12 validation suite (dynamic references, unevaluated keywords, supplied dialects, offline meta-schemas, opt-in format assertions). Adds resource-preserving export and model APIs while keeping the 1.x Draft-7 output of toJsonSchema() and toSchemaModel(). Exercises all 384 required upstream groups against the fixtures merged in test(ack): pin Draft 2020-12 conformance fixtures #169.
• feat(generator): generate models from Draft 2020-12 schemas #167, model generation. Adds the opt-in ack_generator:ack_json_schema builder for Draft 2020-12 bundles. Representable shapes generate typed models; other valid shapes generate schema-validated value models. Extends the ack_json_schema_builder bridge with assertFormats import and preserving export options. Depends on feat(ack): support Draft 2020-12 runtime import and export #171.

Status

Both are parked as drafts and marked "do not merge yet". Neither is rebased onto the 1.7.0-beta.2 main, by intent, until the 2.0 structure is decided. #171 currently conflicts with main.

Before these can merge

• Reconcile feat(ack): support Draft 2020-12 runtime import and export #171 with the 2.0 plan for native Draft 2020-12 export and adapter provider profiles, as its description calls out.
• Rebase feat(ack): support Draft 2020-12 runtime import and export #171 onto main, then feat(generator): generate models from Draft 2020-12 schemas #167 onto feat(ack): support Draft 2020-12 runtime import and export #171.
• Align feat(generator): generate models from Draft 2020-12 schemas #167's generated models with the annotation and model form that feat(ack)!: unify annotations and support primary constructors #184 settles. feat(generator): generate models from Draft 2020-12 schemas #167 generates @AckInfer models; feat(ack)!: unify annotations and support primary constructors #184 introduces @Schemable as the single annotation, with primary constructors, and keeps @AckInfer only as a deprecated spelling.
• Decide how generated models expose their schema (Model.schema, Generator: add a Model.schema shorthand for Model.$ack.modelSchema #173) and how custom types resolve (Generator: resolve a field's type from the type's own schema, and retire @AckField(schema:) #185), since the generator output depends on both.
• Set final package versions and changelog entries in the 2.0 release pull request, not in these.

Out of scope

Optional vocabularies other than format assertions are not claimed as complete in #171.

Related

• test(ack): pin Draft 2020-12 conformance fixtures #169: the Draft 2020-12 fixtures both pull requests test against.
• feat(ack)!: unify annotations and support primary constructors #184: @Schemable with primary constructors.
• Generator: add a Model.schema shorthand for Model.$ack.modelSchema #173, Generator: resolve a field's type from the type's own schema, and retire @AckField(schema:) #185: schema exposure and type-owned schemas.