API Reference

The @hedystia/validations package provides a robust schema builder h to create type-safe schemas for your API.

Core Schemas

These are the starting points for any validation schema.

Method	Return Type	Description
`h.string()`	`StringSchemaType`	Validates that a value is a string.
`h.number()`	`NumberSchemaType`	Validates that a value is a number (excluding `NaN`).
`h.boolean()`	`BooleanSchemaType`	Validates that a value is a boolean (`true`/`false`).
`h.any()`	`AnySchemaType`	Accepts any value without validation.
`h.null()`	`NullSchemaType`	Validates that a value is exactly `null`.
`h.literal(value)`	`LiteralSchema`	Validates an exact match for a `string`, `number`, or `boolean`.
`h.object(definition)`	`ObjectSchemaType`	Validates an object against a key-value schema definition.
`h.array(schema)`	`ArraySchema`	Validates an array where every item matches the provided schema.
`h.enum(values)`	`UnionSchema`	Validates that a value matches one of the provided literal values in the array.
`h.options(...schemas)`	`UnionSchema`	Validates a union of multiple schemas (similar to Zod's `union`).
`h.instanceOf(class)`	`InstanceOfSchema`	Validates that a value is an instance of the specified class.
`h.date()`	`StringSchemaType`	Alias for `h.string().date()`.
`h.uuid()`	`StringSchemaType`	Alias for `h.string().uuid()`.
`h.email()`	`StringSchemaType`	Alias for `h.string().email()`.
`h.phone()`	`StringSchemaType`	Alias for `h.string().phone()`.
`h.domain()`	`StringSchemaType`	Alias for `h.string().domain()`.

Methods available on h.string().

Method	Description
`.minLength(n)`	Ensures the string has at least `n` characters.
`.maxLength(n)`	Ensures the string has at most `n` characters.
`.email()`	Validates common email format.
`.uuid()`	Validates UUID v4 format.
`.regex(ptrn)`	Matches the string against a custom Regular Expression.
`.phone()`	Validates international phone formats.
`.domain(http?)`	Validates domain/URL format. If `true` (default), requires `http` or `https`.
`.date()`	Validates that the string is a valid parseable ISO date.
`.coerce()`	Converts incoming non-string values to string automatically.

Methods available on h.number().

Method	Description
`.min(n)`	Ensures the number is greater than or equal to `n`.
`.max(n)`	Ensures the number is less than or equal to `n`.
`.coerce()`	Converts strings or numeric types to number automatically.

Methods available on most schemas to change their behavior.

Method	Description
`.optional()`	Allows the value to be `undefined`. Maps to `T
`.null()`	Allows the value to be `null`. Maps to `T
`.nullable()`	Alias for `.null()`. Allows the value to be `null`. Maps to `T
`.array()`	Transforms the schema into an array of that type: `T[]`.
`.coerce()`	Enables type coercion for primitive types (string, number, boolean).

Helper	Description
`Infer<typeof T>`	TypeScript utility to extract the output type of a schema.