TypeScript 1:1 schema validation, inspired by ArkType.
The goal of this library is to provide a way to write TypeScript-like type definitions that can be used to validate data at runtime.
Using StereoTyped is very similar to how you would write TypeScript types. To define a type, you can use the type function, which takes
an object with the type definition. This function returns a validation function that throws an error when the input data does not match
the type definition. Here is an example:
import { type } from 'stereotyped';
const parseUser = type({
name: 'string',
age: 'number',
isCool: 'boolean',
isAwesome: '"yes" | "no"',
friends: 'string[]',
'hobbies?': '[string, string]',
address: {
street: 'string',
city: 'string',
zip: 'number',
},
});
const user = parseUser({
name: 'John Doe',
age: 42,
isCool: true,
isAwesome: 'yes',
friends: ['Alice', 'Bob'],
hobbies: ['coding', 'reading'],
address: {
street: '123 Main St',
city: 'Springfield',
zip: 12345,
},
});At this point, the user variable is typed as the following:
type User = {
name: string;
age: number;
isCool: boolean;
isAwesome: 'yes' | 'no';
friends: string[];
hobbies?: [string, string] | undefined;
address: {
street: string;
city: string;
zip: number;
};
};You can infer the parsed type of a schema by using the Infer util type from StereoTyped:
import { type, type Infer } from 'stereotyped';
const schema = type({
name: 'string',
age: 'number',
});
type User = Infer<typeof schema>;
// ^? { name: string, age: number }StereoTyped supports the following types & features:
stringnumberbooleannullundefinedobject- Arrays
- Tuples
- Unions
- Literal types (strings, numbers, booleans)
- Nested objects
- Optional properties
- Required properties