Random JSON Reference Integrity Fixture Generator

Description

Construct bounded linked records with chain, dangling-reference or cycle controls and retain independently traceable reference and cycle labels.

A parser corpus pairs literal input spellings or structured documents with observable parser results or explicitly constructed expectations. Successful parsing, semantic validity, and exact round-trip preservation are separate properties, so test records retain the relevant evidence.

Construct bounded linked records with chain, dangling-reference or cycle controls and retain independently traceable reference and cycle labels.

When to use this tool

Use this generator to create reproducible json reference integrity fixture cases from the supplied model or bank. Inspect the returned evidence before using cases in a test or exercise.

How to use the tool and how it works

Supply ids, mode in the field shapes below. Set seed when you need an explicit replay.
Run the tool and correct any input error. For generated controls, distinguish a successful fixture containing an invalid case from failure to generate the fixture.
Read records, missingReferences, cycleMembers, validReferences, pretty. Use the conventions below and keep answer-bearing fields separate when presenting an exercise.

Shuffle distinct IDs into a next-reference chain and terminate with null, a missing ID, or a link to the first node. Return missing-reference evidence, detected cycle members, and pretty serialized records.^[1]

Input field	Meaning and units	Accepted input
ids	Ids	Required. Array of Text; minimum UTF-16 length 1; maximum UTF-16 length 128.; minimum items 2; maximum items 16.
mode	Mode	Required. Text; one of "chain", "missing", "cycle".
seed	Optional numeric seed; takes precedence over context randomness. Without either, use the fixed tool.io default seed.	Optional. Safe integer.

Output field	Interpretation	Returned shape
records	Records	Required. Array of Object; no unknown keys.; minimum items 2; maximum items 16.
records[].id	Literal identifier used to match records, independently of their display labels.	Required. Text; maximum UTF-16 length 65536.
records[].next	Next	Required. Text; maximum UTF-16 length 65536. or Null.
missingReferences	Missing References	Required. Array of Object; no unknown keys.; minimum items 0; maximum items 16.
missingReferences[].from	From	Required. Text; maximum UTF-16 length 65536.
missingReferences[].target	Target	Required. Text; maximum UTF-16 length 65536.
cycleMembers	Cycle Members	Required. Array of Text; maximum UTF-16 length 65536.; minimum items 0; maximum items 16.
validReferences	Valid References	Required. Boolean.
pretty	Pretty	Required. Text; maximum UTF-16 length 65536.
randomness	Replay metadata: source is seed or context; seed is the normalized 32-bit seed or null for a context source.	Required. Object; no unknown keys.
randomness.seed	Optional numeric replay seed; normalization and precedence are explained below.	Required. Safe integer. or Null.
randomness.source	Source	Required. Text; one of "context", "seed".

An explicit safe-integer seed takes precedence over injected context randomness and is normalized to an unsigned 32-bit integer. With no seed and no context source, replay uses the fixed tool.io default seed. A context source must return finite values from zero inclusive to one exclusive; its advancing state must be retained separately. randomness records the source and normalized seed, or null for context. These generators are not cryptographic random sources.

json

{
  "input": {
    "ids": [
      "a",
      "b",
      "c"
    ],
    "mode": "cycle",
    "seed": 42
  },
  "output": {
    "records": [
      {
        "id": "b",
        "next": "a"
      },
      {
        "id": "a",
        "next": "c"
      },
      {
        "id": "c",
        "next": "b"
      }
    ],
    "missingReferences": [],
    "cycleMembers": [
      "b",
      "a",
      "c"
    ],
    "validReferences": true,
    "pretty": "[\n  {\n    \"id\": \"b\",\n    \"next\": \"a\"\n  },\n  {\n    \"id\": \"a\",\n    \"next\": \"c\"\n  },\n  {\n    \"id\": \"c\",\n    \"next\": \"b\"\n  }\n]\n",
    "randomness": {
      "seed": 42,
      "source": "seed"
    }
  }
}

Limitations and assumptions

validReferences reports only whether targets exist; a cycle can have validReferences true. This models a single-next graph rather than arbitrary JSON references or schema resolution.
A replay requires the same complete input and implementation. Randomized construction does not guarantee uniform coverage of every feasible output; finite samples can repeat unless a distinct-selection rule is explicitly stated.
The field tables state structural bounds; cross-field constraints and bounded search or output budgets also apply. Unknown keys are rejected where the object contract disallows them. Input errors are distinct from null fields and deliberate invalid controls in a successful output.

Alternative or Complementary methods

For a supplied example, inspect the returned construction or delegated check directly. To evaluate a consumer, also test cases chosen for its own boundaries; a generated finite corpus does not establish exhaustive coverage.

References

Tool behavior and example: Random JSON Reference Integrity Fixture Generator — tool.io

Similar or alternative tools

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