Trim¶

trim is a built‑in normalization rule that removes leading and trailing whitespace from string values.

It normalizes text edges while preserving the internal content exactly as provided. If the value is not a string, or trimming does not change the value, no normalization step is emitted.

Signature¶

export const trim: NormalizationRule<unknown>
(value: unknown, mode: NormalizationMode, path: FieldPath) => NormalizationStep[]

Events¶

Event code	Description
`string.now.trimmed`	Leading and trailing whitespace was removed.

Design rationale¶

Normalizes only edges of the string; internal whitespace is handled by other rules.
Produces consistent, predictable text for downstream validators, scanners, and policy layers.
Eliminates accidental spacing introduced by user input, copy‑paste operations, or UI frameworks.
Emits a normalization step only when the trimmed string differs from the original.
Classified as lossless normalization — no semantic content is removed.
Ensures clean text boundaries without altering user intent.

Invoke¶

trim runs automatically when:

The value is structurally a string.
The normalization stage is active.
The current mode allows lossless normalization.

Mode behavior:

strict: Rule does not run.
moderate: Rule runs (this rule is lossless).
lax: Rule runs.

Normalization cannot be invoked manually. It is always applied automatically based on structural type and mode.

Examples¶

Leading and trailing whitespace removed¶

const value = "   hello world   ";

const result = trim(value, "strict", "$");
// → [
//     {
//       path: "$",
//       nextValue: "hello world",
//       lossy: "lossless",
//       events: [
//         JaneEvent{ kind: "info", code: "string.now.trimmed", ... }
//       ]
//     }
//   ]

No trimming needed — no normalization¶

const result = trim("hello world", "strict", "$");
// → []

Non‑string value¶

const result = trim(42, "strict", "$");
// → []