feat(ts): Add types and ts documentation

index.d.ts

@@ -0,0 +1,15 @@
+import {
+  type FastifyInstance,
+  type FastifyBaseLogger,
+  type FastifyReply,
+  type FastifyRequest,
+} from "fastify";
+
+declare namespace fastifyasyncforge {
+  export function app<T extends FastifyInstance>(): T;
+  export function request<T extends FastifyRequest>(): T;
+  export function reply<T extends FastifyReply>(): T;
+  export function logger<T extends FastifyBaseLogger>(): T;
+}
+
+export = fastifyasyncforge;

index.test-d.ts

@@ -0,0 +1,45 @@
+import { expectAssignable, expectError, expectType } from "tsd";
+import { app, logger, reply, request } from ".";
+import fastify, {
+  type FastifyInstance,
+  type FastifyBaseLogger,
+  type FastifyRequest,
+  type FastifyReply,
+  type RawServerDefault,
+  type RouteGenericInterface,
+} from "fastify";
+
+const fastifyInstance = fastify();
+
+// app
+expectAssignable<FastifyInstance>(fastifyInstance);
+expectAssignable<FastifyInstance>(app());
+expectAssignable<FastifyInstance>(app<FastifyInstance<RawServerDefault>>());
+expectError<FastifyInstance>(app<string>());
+expectError<FastifyInstance>({});
+
+// request
+expectType<FastifyRequest>(request());
+expectType<FastifyRequest>(request<FastifyRequest<RouteGenericInterface>>());
+expectError<FastifyRequest>(request<boolean>());
+expectType<unknown>(request().body);
+expectType<boolean>(request().is404);
+expectError<FastifyRequest>({});
+
+// reply
+expectType<FastifyReply>(reply());
+expectType<FastifyReply>(reply<FastifyReply<RawServerDefault>>());
+expectType<number>(reply().statusCode);
+expectType<boolean>(reply().sent);
+expectError<FastifyReply>(reply<number>());
+expectError<FastifyReply>({});
+
+// logger
+expectType<FastifyBaseLogger>(fastifyInstance.log);
+expectType<FastifyBaseLogger>(logger());
+expectType<FastifyBaseLogger>(logger<FastifyBaseLogger>());
+expectType<void>(logger().debug({ msg: "hey" }));
+expectType<void>(logger().info({ msg: "oh!" }));
+expectType<void>(logger().warn({ msg: "let's go!!!" }));
+expectError<FastifyBaseLogger>(logger<object>());
+expectError<FastifyBaseLogger>({});