Description
Compose supplied filename parts into hidden, multi-dot, case, and trailing-separator cases with delegated extension classifications.
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.
Compose supplied filename parts into hidden, multi-dot, case, and trailing-separator cases with delegated extension classifications.
When to use this tool
Use this generator to create reproducible file extension edge case corpus 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 stems, suffixes, prefixes, count 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 cases. Use the conventions below. Keep answer-bearing fields separate when presenting an exercise.
For each sampled stem, suffix, and path prefix, create ordinary, hidden, multiple-dot, uppercase, trailing-dot, and trailing-separator spellings. Delegate extension extraction and expected-extension matching for all six cases.1
Delegated operations used for this result: file extension. Their calculation or parsing conventions apply to the corresponding result fields.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| stems | Stems | Required. Array of Text; minimum UTF-16 length 1; maximum UTF-16 length 128.; minimum items 1; maximum items 128. |
| suffixes | Suffixes | Required. Array of Text; minimum UTF-16 length 1; maximum UTF-16 length 128.; minimum items 1; maximum items 128. |
| prefixes | Prefixes | Required. Array of Text; maximum UTF-16 length 128.; minimum items 1; maximum items 128. |
| count | Count | Required. Safe integer; minimum 1; maximum 128. |
| 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 |
|---|---|---|
| cases | Cases | Required. Array of Object; no unknown keys.; minimum items 6; maximum items 768. |
| cases[].kind | Kind | Required. Text; maximum UTF-16 length 4096. |
| cases[].filename | Filename | Required. Text; maximum UTF-16 length 4096. |
| cases[].expectedExtension | Expected Extension | Required. Text; maximum UTF-16 length 4096. |
| cases[].extension | Extension | Required. Text; maximum UTF-16 length 4096. |
| cases[].matches | Matches | Required. Boolean. |
| randomness | Replay source and normalized 32-bit seed, or null seed for an advancing context source. | Required. Object; no unknown keys. |
| randomness.seed | Optional safe-integer 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": {
"stems": [
"report",
"archive"
],
"suffixes": [
"csv",
"txt"
],
"prefixes": [
"",
"tmp/"
],
"count": 1,
"seed": 42
},
"output": {
"cases": [
{
"kind": "ordinary",
"filename": "tmp/archive.csv",
"expectedExtension": "csv",
"extension": "csv",
"matches": true
},
{
"kind": "hidden",
"filename": "tmp/.archive",
"expectedExtension": "csv",
"extension": "",
"matches": false
},
{
"kind": "multiple-dots",
"filename": "tmp/archive.part.csv",
"expectedExtension": "csv",
"extension": "csv",
"matches": true
},
{
"kind": "uppercase",
"filename": "tmp/archive.CSV",
"expectedExtension": "csv",
"extension": "csv",
"matches": true
},
{
"kind": "trailing-dot",
"filename": "tmp/archive.csv.",
"expectedExtension": "csv",
"extension": "",
"matches": false
},
{
"kind": "trailing-separator",
"filename": "tmp/archive.csv/",
"expectedExtension": "csv",
"extension": "",
"matches": false
}
],
"randomness": {
"seed": 42,
"source": "seed"
}
}
}Limitations and assumptions
- count produces six cases per draw. An extension is a lexical filename property, not a MIME type, content inspection, or security decision; no filesystem access occurs.
- A replay requires the same complete input and implementation. The stated sampling convention applies within its eligible space. A finite draw does not exhaust all possible outputs; repeats remain possible unless a distinct-selection rule is explicit.
- 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
Similar or alternative tools
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