feat: Add defaultValue to schemas

src/SchemaItem.ts

@@ -1,7 +1,9 @@
 /* eslint-disable id-length */
 import { objectClean } from '@dzeio/object-util'
 import { StandardSchemaV1 } from '@standard-schema/spec'
-import Schema, { SchemaNullable } from './Schema'
+import SchemaNullable from 'items/nullable'
+import { isNull } from './helpers'
+import Schema, { parceable } from './Schema'
 import { SchemaJSON, ValidationError, ValidationResult } from './types'
 export default abstract class SchemaItem<Type = any> implements StandardSchemaV1<Type> {
 
@@ -71,6 +73,18 @@ export default abstract class SchemaItem<Type = any> implements StandardSchemaV1
 		}
 	}
 
+	@parceable()
+	public defaultValue(value: Type, strict = true) {
+		this.addPreProcess((input) => {
+			if (strict && isNull(input) || !strict && !input) {
+				return value
+			}
+			return input
+		})
+
+		return this
+	}
+
 	public attrs(...attributes: Array<string>) {
 		this.attributes.concat(attributes)
 		return this

src/helpers.ts

@@ -5,6 +5,10 @@ import SchemaNullable from 'items/nullable'
 import SchemaObject from 'items/object'
 import type SchemaItem from 'SchemaItem'
 
+export function isNull(value: unknown): value is undefined | null {
+	return typeof value === 'undefined' || value === null
+}
+
 export function parseQuery<T extends SchemaItem>(model: T, query: URLSearchParams, opts?: Parameters<T['parse']>[1]): ReturnType<T['parse']> {
 	const record: Record<string, unknown> = {}
 	for (const [key, value] of query) {