Type-safe runtime schema validation and parsing
npm i @hazae41/gardien- 100% TypeScript and ESM
- No external dependencies
- Rust-like patterns
- Fully type-safe
- Unit-tested
- Zod-like syntax
We can parse something as a number and then validate it
import { Guard, z } from "@hazae41/gardien"
const value = Guard.asOrThrow(z.numberable().nonNegative(), "0x123")This is like
const value = Number("0x123")
if (value < 0)
throw new Error()
return valueimport { Guard, z } from "@hazae41/gardien"
Guard.asOrThrow(z.string().minmax(6, 24, "Password must be between 6 and 24 characters"), password)This is like
if (typeof password !== "string")
throw new Error()
if (password.length < 6)
throw new Error("Password must be between 6 and 24 characters")
if (password.length > 24)
throw new Error("Password must be between 6 and 24 characters")We can define complex guards that include other guards
import { Guard, z } from "@hazae41/gardien"
const RpcRequestGuard = z.record({
jsonrpc: z.strong("2.0"),
id: z.union([z.strong(null), z.number(), z.string()]),
method: z.string(),
params: z.optional(z.unknown())
} as const)
function onMessage(message: string) {
const request = Guard.asOrThrow(RpcRequestGuard, JSON.parse(message) as unknown)
if (request.method === "example")
return void example(request)
throw new Error("Unknown method")
}We can define high-order guards that dynamically include other guards
import { Guard, z } from "@hazae41/gardien"
const RpcRequestGuard = <M extends Guard<string, string>, P extends Guard>(method: M, params: P) => z.record({
jsonrpc: z.strong("2.0"),
id: z.union([z.strong(null), z.number(), z.string()]),
method: method,
params: params
} as const)
const ExampleParamsGuard = z.record({
example: z.string()
} as const)
const request = Guard.asOrThrow(RpcRequestGuard(z.strong("example"), ExampleParamsGuard), JSON.parse(message) as unknown)class IPv4Guard {
static asOrThrow(value: string): string {
if (!/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.test(value))
throw new Error()
return value
}
}
Guard.asOrThrow(z.string().pipe(IPv4Guard, "This is not an IPv4 address"), input)class ZeroHexlifyGuard {
static asOrThrow(value: any): `0x${string}` {
return `0x${BigInt(value).toString(16)}`
}
}
const hex = Guard.asOrThrow(ZeroHexlifyGuard, "12345")