Coverage Review: JSON Schema Unit Test Fixtures

[lmmx]

Context

We currently have a set of unit test fixtures for JSON Schema validation.
Before moving on to larger integration tests, we should confirm that our fixture set covers the full range of features defined in the JSON Schema 2020-12 specification.

This issue is a tracking checklist to highlight what we already have fixtures for and identify any obvious omissions.

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Coverage Checklist

1. Metadata

• $schema
• $id
• title
• description

2. Core Types

• type: string, number, integer, boolean, null, array, object
• Empty schema {} (accepts everything)
• Boolean schemas (true / false)

3. String Constraints

• minLength
• maxLength
• pattern
• format (e.g. email, uri, date-time)

4. Numeric Constraints

• minimum
• maximum
• exclusiveMinimum
• exclusiveMaximum
• multipleOf

5. Array Constraints

• items (single schema)
• items (tuple validation)
• additionalItems
• minItems (via required objects inside array elements)
• maxItems
• uniqueItems
• contains

6. Object Constraints

• properties
• required
• additionalProperties
• patternProperties
• minProperties
• maxProperties
• dependencies / dependentRequired
• dependentSchemas

7. Composition

• allOf
• anyOf
• oneOf
• not

8. Conditionals

• if
• then
• else

9. References & Reuse

• $ref (local)
• $ref (remote)
• Recursive $ref
• $defs / definitions

[lmmx]

There are initially 25 untested items from the JSON schema spec

1. Empty schema {} (accepts everything)
2. Boolean schemas (true / false)
3. minLength
4. maxLength
5. format (e.g. email, uri, date-time)
6. maximum
7. exclusiveMinimum
8. exclusiveMaximum
9. multipleOf
10. additionalItems
11. maxItems
12. uniqueItems
13. contains
14. patternProperties
15. minProperties
16. maxProperties
17. dependencies / dependentRequired
18. dependentSchemas
19. allOf
20. not
21. if
22. then
23. else
24. $ref (remote)
25. Recursive $ref