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normalizeNonEmptyString

Normalizes a value into a trimmed, non‑empty string or returns null.

This helper accepts only native JavaScript strings. It trims leading and trailing whitespace and rejects empty results. It never throws and never mutates input. Use this when you need a guaranteed non‑empty string before validation or further processing.

Signature

function normalizeNonEmptyString(value: unknown): string | null

Parameters

Name Data type Description
value unknown The value to normalize to a non-empty string.

Returns

One of:

  • A trimmed, non‑empty string.
  • null: If the value is not a string or becomes empty after trimming.

Behavior

  • Only native strings are accepted.
  • The returned string is trimmed.
  • If the trimmed result is empty, null is returned.
  • All non‑string values return null.
  • No coercion (for example, converting numbers to strings) is performed.

Examples

normalizeNonEmptyString("hello")        // "hello"
normalizeNonEmptyString("  hello  ")    // "hello"

normalizeNonEmptyString("")             // null
normalizeNonEmptyString("   ")          // null

normalizeNonEmptyString(123)            // null
normalizeNonEmptyString(null)           // null
normalizeNonEmptyString(undefined)      // null

Notes

  • Use normalizeString if empty strings should be preserved.
  • Use validateNonEmptyString if you need a Result<T> instead of null.