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No space

noSpace validates that a string contains no whitespace characters (spaces, tabs, newlines, etc.).

It enforces strict structural string validation and rejects any non-string value or string containing any whitespace. If the value is not a string or contains whitespace, the rule emits a single validation event. Otherwise, it produces no validation output.

Signature

Through the API:

.noSpace()

And internally:

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

Events

Event code Description
type.not.valid Value is not structurally a string
string.has.whitespace String contains whitespace characters

Design rationale

  • Provides a strict, predictable whitespace-free string validation.
  • Rejects non-string values with a clear structural-type diagnostic.
  • Never coerces or normalizes — validation is explicit and opt-in.
  • Emits exactly one event per failure for clarity and composability.
  • Async-compatible and returns a readonly array of JaneEvent objects.

Invoke

noSpace 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 type.not.valid.
  • If the value is a string but contains whitespace, emits string.has.whitespace.
  • If the value is a string with no whitespace → returns an empty result set.

Examples

Valid string with no whitespace

await noSpace("hello", "$");
// → []

String with spaces

await noSpace("hello world", "$");
// → [
//     JaneEvent{
//       kind: "error",
//       code: "string.has.whitespace",
//       path: "$",
//       ...
//     }
//   ]

Non-string value

await noSpace(42, "$");
// → [
//     JaneEvent{
//       kind: "error",
//       code: "type.not.valid",
//       path: "$",
//       ...
//     }
//   ]