Overview

Primitive type guards check whether a value is one of JavaScript’s built‑in primitive types. They return simple booleans, never throw, and never mutate input.

• isBigInteger: Checks whether a value is a bigint primitive.
• isBoolean: Checks whether a value is a boolean.
• isFiniteNumber: Checks whether a value is a finite number.
• isInteger: Checks whether a value is an integer.
• isNonEmptyString: Checks whether a value is a non‑empty string.
• isNonNegativeNumber: Checks whether a value is a non‑negative number.
• isNull: Checks whether a value is null.
• isNullOrUndefined: Checks whether a value is null or undefined.
• isNumber: Checks whether a value is a number.
• isPositiveInteger: Checks whether a value is a positive integer.
• isSafeInteger: Checks whether a value is a safe integer.
• isString: Checks whether a value is a string.
• isSymbol: Checks whether a value is a symbol.
• isUndefined: Checks whether a value is undefined.

All primitive guards are pure, predictable, and safe to use before normalization or validation.