referencing 0.37.0: Resource

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify referencing.Resource in pkg:pypi/referencing@0.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:pypi/referencing@0.37.0
Demonstrate these symbols/APIs:
  - referencing.Resource

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:f85f6edbc62fba26aebd3e9dfd79f3c5d6f0e638d330d541829bcf8bb7347e4a","contract":["Resource.from_contents() creates a Resource instance from JSON schema data and auto-detects $schema specification and $id.","Resource.from_contents() accepts default_specification to identify schemas without an explicit $schema keyword.","Resource.from_contents() raises CannotDetermineSpecification when schema dialect cannot be identified and no default is provided.","Resource.opaque() wraps arbitrary mapping or data as an opaque resource without subresources or anchor resolution.","Resource.anchors() retrieves schema anchors ($anchor) with their respective name and Resource references.","Resource.subresources() iterates over all subresources embedded within the document.","Resource.pointer() resolves JSON pointer references using a Resolver and raises PointerToNowhere for invalid paths.","Resource instances support value equality comparison based on contents and specification."],"goal":"verify referencing.Resource in pkg:pypi/referencing@0.37.0","kind":"HOW","packages":["pkg:pypi/referencing@0.37.0"],"schemaVersion":1,"symbols":["referencing.Resource"]},"contractCommand":["python","test/contract.py"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"pypi","executionContext":"python","language":"python","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"pip","runtime":"python","schemaVersion":1},"license":"MIT-0","packages":["pkg:pypi/referencing@0.37.0"],"schemaVersion":1,"subject":"pkg:pypi/referencing@0.37.0","symbols":["referencing.Resource"],"verifierAdapter":"python@1"}

referencing==0.37.0

{
  "schemaVersion": 1,
  "goal": "verify referencing.Resource in pkg:pypi/referencing@0.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:pypi/referencing@0.37.0"
  ],
  "symbols": [
    "referencing.Resource"
  ]
}

from referencing import Registry, Resource
from referencing.exceptions import CannotDetermineSpecification, PointerToNowhere
from referencing.jsonschema import DRAFT7, DRAFT202012


def test_resource_from_contents_with_schema():
    schema = {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "$id": "https://example.com/root",
        "$anchor": "root-anchor",
        "type": "object",
        "properties": {
            "name": {"type": "string"},
            "nested": {
                "$id": "https://example.com/nested",
                "$anchor": "nested-anchor",
                "type": "boolean",
            },
        },
    }
    res = Resource.from_contents(schema)
    assert res.contents == schema
    assert res.id() == "https://example.com/root"
    assert res._specification == DRAFT202012


def test_resource_from_contents_with_default_specification():
    schema_without_id = {"type": "string", "maxLength": 100}
    res = Resource.from_contents(schema_without_id, default_specification=DRAFT7)
    assert res.contents == schema_without_id
    assert res.id() is None
    assert res._specification == DRAFT7


def test_resource_from_contents_cannot_determine_specification():
    schema_ambiguous = {"type": "integer"}
    try:
        Resource.from_contents(schema_ambiguous)
        raise AssertionError("Resource.from_contents should have raised CannotDetermineSpecification")
    except CannotDetermineSpecification:
        pass


def test_resource_opaque():
    data = {"arbitrary": "data", "count": 42}
    res_opaque = Resource.opaque(data)
    assert res_opaque.contents == data
    assert res_opaque.id() is None
    assert list(res_opaque.anchors()) == []
    assert list(res_opaque.subresources()) == []


def test_resource_anchors():
    schema = {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "$id": "https://example.com/anchored",
        "$anchor": "main-anchor",
        "type": "object",
    }
    res = Resource.from_contents(schema)
    anchors = list(res.anchors())
    assert len(anchors) == 1
    assert anchors[0].name == "main-anchor"
    assert anchors[0].resource == res


def test_resource_subresources():
    schema = {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "$id": "https://example.com/parent",
        "type": "object",
        "properties": {
            "child": {
                "$id": "https://example.com/child",
                "type": "string",
            },
        },
    }
    res = Resource.from_contents(schema)
    subresources = list(res.subresources())
    assert len(subresources) == 1
    assert subresources[0].id() == "https://example.com/child"
    assert subresources[0].contents == {"$id": "https://example.com/child", "type": "string"}


def test_resource_pointer_and_pointer_to_nowhere():
    schema = {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "$id": "https://example.com/document",
        "type": "object",
        "properties": {
            "title": {"type": "string"},
        },
    }
    res = Resource.from_contents(schema)
    registry = Registry().with_resource("https://example.com/document", res)
    resolver = registry.resolver()

    resolved = res.pointer("/properties/title", resolver=resolver)
    assert resolved.contents == {"type": "string"}

    try:
        res.pointer("/properties/nonexistent", resolver=resolver)
        raise AssertionError("res.pointer should have raised PointerToNowhere")
    except PointerToNowhere as exc:
        assert exc.ref == "/properties/nonexistent"


def test_resource_equality():
    schema1 = {"$schema": "https://json-schema.org/draft/2020-12/schema", "type": "number"}
    schema2 = {"$schema": "https://json-schema.org/draft/2020-12/schema", "type": "number"}
    schema3 = {"$schema": "https://json-schema.org/draft/2020-12/schema", "type": "string"}

    res1 = Resource.from_contents(schema1)
    res2 = Resource.from_contents(schema2)
    res3 = Resource.from_contents(schema3)

    assert res1 == res2
    assert res1 != res3


def main():
    test_resource_from_contents_with_schema()
    test_resource_from_contents_with_default_specification()
    test_resource_from_contents_cannot_determine_specification()
    test_resource_opaque()
    test_resource_anchors()
    test_resource_subresources()
    test_resource_pointer_and_pointer_to_nowhere()
    test_resource_equality()
    print("CONTRACT PASS: referencing.Resource verified offline")


if __name__ == "__main__":
    main()