Feature Flags

All of Isin’s optional integrations are off by default and purely additive. Enabling one never changes what counts as a valid ISIN, only what you can do with an Isin once you have one.

[dependencies]
ftracker-identifiers = { version = "0.0.1", features = ["serde", "schemars", "arbitrary", "proptest"] }

serde

(De)serializes Isin as its canonical 12-character string (e.g. "US0378331005"), so it round-trips as a plain identifier in JSON, YAML, or config files.

Deserialization always re-runs full validation: an untrusted payload (a malformed API request, a hand-edited config file) can never produce an invalid Isin. A bad value fails to deserialize with a descriptive error instead of silently producing garbage.

use ftracker_identifiers::Isin;

let isin = Isin::parse("US0378331005").unwrap();
let json = serde_json::to_string(&isin).unwrap();
assert_eq!(json, "\"US0378331005\"");

let back: Isin = serde_json::from_str(&json).unwrap();
assert_eq!(isin, back);

// Invalid input is rejected at deserialization time, not silently accepted.
assert!(serde_json::from_str::<Isin>("\"not-an-isin\"").is_err());

schemars

Implements JsonSchema for Isin, so it can appear in a generated OpenAPI/JSON Schema document as a pattern-constrained string rather than an opaque string type. This feature implies serde.

The generated schema:

{
  "type": "string",
  "format": "isin",
  "minLength": 12,
  "maxLength": 12,
  "pattern": "^[A-Z]{2}[A-Z0-9]{9}[0-9]$",
  "description": "ISIN (International Securities Identification Number, ISO 6166), Luhn checksum-valid."
}

Note that the pattern alone doesn’t capture the Luhn checksum constraint. Schema validators outside this crate (API gateways, other-language clients) can reject malformed shapes, but true checksum validation still requires this crate (or a reimplementation of the same algorithm; see Structure & Formats).

arbitrary

Implements Arbitrary for Isin, so fuzz targets (e.g. via cargo fuzz) can generate structurally valid, checksum-correct Isin values directly, instead of generating raw strings that mostly fail validation before reaching the code under test.

proptest

Exposes reusable proptest strategies at ftracker_identifiers::isin::proptest:

• isin::proptest::valid_isin() — a Strategy<Value = Isin> producing checksum-correct values with a two-letter country code and an alphanumeric NSIN.
• isin::proptest::valid_isin_string() — the same, rendered as a canonical String, useful for round-trip-through-parsing property tests.

This is the recommended way to property-test your own code that accepts an Isin, without hand-rolling a checksum-valid generator:

use ftracker_identifiers::{isin::proptest::valid_isin, Isin};
use proptest::proptest;

proptest! {
    #[test]
    fn my_function_accepts_any_valid_isin(isin in valid_isin()) {
        // exercise your own code with `isin` here
    }
}