Description
Partition shuffled supplied records into synthetic cursor pages, optional empty pages, and parser-checked next links with consistent termination.
A protocol fixture is local test data representing headers, messages, identifiers, or request decisions. Serialization and parsing can be checked without contacting a server, while authentication, delivery, and actual client behavior require separate tests.
Partition shuffled supplied records into synthetic cursor pages, optional empty pages, and parser-checked next links with consistent termination.
When to use this tool
Use this generator to create reproducible paginated api response sequence 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 records, minimumPageSize, maximumPageSize, emptyPageProbability, terminalEmptyPage 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 pages, recordOrder. Use the conventions below and keep answer-bearing fields separate when presenting an exercise.
Shuffle unique records and partition them with sampled page sizes, optionally inserting empty intermediate pages and a terminal empty page. Assign explicit cursors, build next Link headers, and delegate their parsing.1
Delegated operations used for this result: query string; link header parser. Their calculation or parsing conventions apply to the corresponding result fields.2, 3
| Input field | Meaning and units | Accepted input |
|---|---|---|
| records | Records | Required. Array of Object; no unknown keys.; minimum items 0; maximum items 128. |
| records[].id | Literal identifier used to match records, independently of their display labels. | Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 128. |
| records[].value | Value | Required. Text; maximum UTF-16 length 4096. |
| minimumPageSize | Minimum Page Size | Required. Safe integer; minimum 1; maximum 128. |
| maximumPageSize | Maximum Page Size | Required. Safe integer; minimum 1; maximum 128. |
| emptyPageProbability | Empty Page Probability | Required. Finite number; minimum 0; maximum 1. |
| terminalEmptyPage | Terminal Empty Page | Required. Boolean. |
| 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 |
|---|---|---|
| pages | Pages | Required. Array of Object; no unknown keys.; minimum items 1; maximum items 128. |
| pages[].cursor | Cursor | Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 128. |
| pages[].records | Records | Required. Array of Object; no unknown keys.; minimum items 0; maximum items 128. |
| pages[].records[].id | Literal identifier used to match records, independently of their display labels. | Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 128. |
| pages[].records[].value | Value | Required. Text; maximum UTF-16 length 4096. |
| pages[].nextCursor | Next Cursor | Required. Text; minimum UTF-16 length 1; maximum UTF-16 length 128. or Null. |
| pages[].linkHeader | Link Header | Required. Text; maximum UTF-16 length 4096. |
| pages[].parsedLinkTargets | Parsed Link Targets | Required. Array of Text; maximum UTF-16 length 4096.; minimum items 0; maximum items 1. |
| recordOrder | Record Order | Required. Array of Text; minimum UTF-16 length 1; maximum UTF-16 length 128.; minimum items 0; maximum items 128. |
| 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.
{
"input": {
"records": [
{
"id": "a",
"value": "alpha"
},
{
"id": "b",
"value": "beta"
},
{
"id": "c",
"value": "gamma"
}
],
"minimumPageSize": 1,
"maximumPageSize": 2,
"emptyPageProbability": 0.5,
"terminalEmptyPage": true,
"seed": 42
},
"output": {
"pages": [
{
"cursor": "page-1",
"records": [
{
"id": "c",
"value": "gamma"
},
{
"id": "a",
"value": "alpha"
}
],
"nextCursor": "page-2",
"linkHeader": "</items?cursor=page-2&limit=2>; rel=\"next\"",
"parsedLinkTargets": [
"/items?cursor=page-2&limit=2"
]
},
{
"cursor": "page-2",
"records": [
{
"id": "b",
"value": "beta"
}
],
"nextCursor": "page-3",
"linkHeader": "</items?cursor=page-3&limit=2>; rel=\"next\"",
"parsedLinkTargets": [
"/items?cursor=page-3&limit=2"
]
},
{
"cursor": "page-3",
"records": [],
"nextCursor": null,
"linkHeader": "",
"parsedLinkTargets": []
}
],
"recordOrder": [
"c",
"a",
"b"
],
"randomness": {
"seed": 42,
"source": "seed"
}
}
}Limitations and assumptions
- An empty page can still have a nextCursor; consumers must not infer termination from record count alone. All original records appear once and no endpoint is contacted.
- 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
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