Predicate function - Validation

The validation functions are used for conditions and rule-based validation logic.

These predicates support conditional validation logic rather than format or type checks.
Inputs may be of any type , unless otherwise specified.
Null , undefined , empty strings, empty arrays, and empty objects are treated explicitly and consistently.
Validation predicates are commonly used in forms, workflow rules, and business logic.

Function	Description	Example
IsRequired(value)	Returns true if the value is present and not empty/null.	"text" is true 0 is true false is true "" is false " " is false null is false [] is false
IsOptional(value)	Returns true if a value is absent, null, undefined, or empty.	null is true "" is true " " is true [] is true {} is true "data" is false 0 is false false is false
IsValidWhen(value, condition)	Returns true if: the condition is false (validation does not apply), or the condition is true and the value satisfies IsRequired.	IsValidWhen("value", true) is true IsValidWhen(null, false) is true IsValidWhen(" ", false) is true IsValidWhen(null, true) is false IsValidWhen(" ", true) is false
IsInvalidWhen(value, condition)	Returns true if: the condition is false (validation does not apply), or the condition is true and the value is empty or absent.	IsInvalidWhen(null, true) is true IsInvalidWhen(" ", true) is true IsInvalidWhen("abc", true) is false IsInvalidWhen(123, true) is false