Schema - Alias

The .alias method is used to rename a property in a schema for validation purposes. It allows you to change the key name for validation and error messages, which is particularly useful when you need to provide more user-friendly or human-readable names in error messages without altering the actual data structure.

This method is essential when validating structured data like user profiles or form submissions, especially when the original property names are not suitable for display in error messages.

Signature

.alias(valueName: string): Schema

• valueName: The alias name to be displayed in validation error messages.
• Returns: The schema instance, allowing method chaining.

📌 Note: This method only affects error message output. It does not rename the actual key in the validated data.

Example: Comparing Validation with and without .alias()

import { schema } from "vkrun";
 
// Without alias
const noAliasSchema = schema().object({
  username: schema().string(),
});
 
const resultNoAlias = noAliasSchema.test({ username: 123 });
console.log(resultNoAlias.errors[0].message);
// "username must be a string type!"
 
// With alias
const aliasSchema = schema().object({
  username: schema().string().alias("user name"),
});
 
const resultWithAlias = aliasSchema.test({ username: 123 });
console.log(resultWithAlias.errors[0].message);
// "user name must be a string type!"

This demonstrates how .alias() helps make error messages more readable while keeping the original structure intact.