Jade Development Guide

Jade is JSON Schema Draft 2020-12 for Wado.

• WEP: Jade — the design and why.
• research-format.md — what the specifications and implementations say about the date and time formats.

Principles

Compliance with the specification comes first. Whether to comply is never an open question: the answer is always yes, because a schema means the same thing to every tool only when each one follows the specification.

Sources

The rules come from the specification: JSON Schema Core and Validation, Draft 2020-12. vendor/JSON-Schema-Test-Suite/tests/draft2020-12/ is the conformance corpus, read as data. No validator's source is read.

Formats

A format means what Draft 2020-12 defines, read strictly: by the grammar the specification cites, as the Test Suite's optional/format/ cases hold it. Jade defines no format of its own and writes no format name the specification does not define, whatever another tool or registry uses. A derived schema takes a format only when every text its type writes meets it.

x-wado-format names the Wado type a string is the text of, in symbol notation (core:temporal#Instant). It is an annotation, which no validator asserts: JSON Schema forbids an x- keyword from affecting evaluation.

Layout

• src/document.wado — Document, the JSON tape every schema and instance is read into.
• src/schema.wado — Schema, one field per keyword, and its reader.
• src/derive.wado — JsonSchema, a schema derived from a Wado type.
• src/validate.wado — Validator, a schema compiled and held against documents, and SchemaSet, the documents its references reach.
• src/format.wado — the formats a validator asserts when compiled to.
• meta/ — Draft 2020-12's meta-schemas as json-schema.org serves them, under the specification's license. A reference reaches them without their being supplied.
• tools/suite.wado — writes tests/generated/ from the Test Suite (mise run suite-jade).

Running tests

wado test package-jade