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Bigint equals

bigintEquals validates that a value is a string representing a BigInt equal to a specified target.

It enforces strict bigint‑string semantics: the value must be a string, must parse successfully as a BigInt literal, and must equal the provided target. If any condition fails, the rule emits a single validation event. Otherwise, it produces no validation output.

Signature

Through the API:

.bigintEquals(target);

And internally:

export const bigintEquals: (target: bigint) => ValidationRule
(value: unknown, path: FieldPath) => Promise<ReadonlyArray<JaneEvent>>

Events

Event code Description
bigint.not.string Value is not a string.
bigint.not.bigint String is not a valid bigint literal.
bigint.not.equal Parsed bigint does not equal the required target.

Design rationale

  • Enforces strict bigint‑string validation with no coercion or normalization.
  • Rejects non‑string values early with a structural‑type diagnostic.
  • Uses JavaScript’s BigInt() constructor for canonical parsing.
  • Treats empty strings and malformed literals as invalid bigint values.
  • Emits exactly one event per failure for clarity and composability.
  • Pure, total, async‑compatible, and returns a readonly array of JaneEvent objects.
  • Preserves the provided path and supports pipeline‑level userMessage overrides.

Invoke

bigintEquals runs only when explicitly included in a boundary or pipeline. It does not run automatically.

The rule activates when:

  • The value is any JavaScript value.
  • If the value is not a string, emits bigint.not.string.
  • If the string is empty or cannot be parsed by BigInt, emits bigint.not.bigint.
  • If the parsed bigint does not equal target, emits bigint.not.equal.
  • Otherwise, returns an empty result set.

Examples

Valid — bigint string equals target

const rule = bigintEquals(42n);

await rule("42", "$");
// → []

Invalid — not a string

await bigintEquals(10n)(123, "$");
// → [
//     JaneEvent{
//       kind: "error",
//       code: "bigint.not.string",
//       path: "$",
//       ...
//     }
//   ]

Invalid — malformed bigint literal

await bigintEquals(10n)("01", "$");
// → [
//     JaneEvent{
//       kind: "error",
//       code: "bigint.not.bigint",
//       path: "$",
//       ...
//     }
//   ]