feat(typescript): add typescript definitions

The default export is the fastifySensible plugin, whereas the http
errors are also being exported but namely.

index.d.ts

@@ -0,0 +1,61 @@
+import * as fastify from "fastify";
+import * as http from "http";
+import * as proxyAddr from "proxy-addr";
+import { HttpErrors } from "./lib/httpError";
+
+declare module "fastify" {
+  namespace SensibleTypes {
+    type ToType<T> = [Error, T];
+  }
+
+  interface Assert {
+    (condition: boolean, code: number, message: string): string;
+    ok(condition: boolean, code: number, message: string): string;
+    equal<T, U>(a: T, b: U, code: number, message: string): string;
+    notEqual<T, U>(a: T, b: U, code: number, message: string): string;
+    strictEqual<T, U>(a: T, b: U, code: number, message: string): string;
+    notStrictEqual<T, U>(a: T, b: U, code: number, message: string): string;
+    deepEqual<T, U>(a: T, b: U, code: number, message: string): string;
+    notDeepEqual<T, U>(a: T, b: U, code: number, message: string): string;
+  }
+
+  interface To {
+    <T>(to: Promise<T>): Promise<SensibleTypes.ToType<T>>;
+  }
+
+  interface FastifyInstance extends HttpErrors {
+    assert: Assert;
+    to: To;
+  }
+
+  interface VaryReply {
+    vary(field: string | string[]): void;
+    append(header: string, field: string | string[]): string;
+  }
+
+  interface FastifyReply<HttpResponse> {
+    vary(field: string | string[]): void;
+  }
+
+  interface FastifyRequest<HttpRequest> {
+    forwarded(): string[];
+    proxyaddr(
+      trust:
+        | proxyAddr.Address
+        | proxyAddr.Address[]
+        | ((addr: string, i: number) => boolean)
+    ): string;
+    is(types: Array<string>): string | false | null;
+    is(...types: Array<string>): string | false | null;
+  }
+}
+
+declare const fastifySensible: fastify.Plugin<
+  http.Server,
+  http.IncomingMessage,
+  http.ServerResponse,
+  {}
+>;
+
+export { HttpErrorType } from "./lib/httpError";
+export default fastifySensible;

lib/httpError.d.ts

@@ -0,0 +1,54 @@
+import createHttpError from 'http-errors';
+
+export type HttpErrorType = {
+    badRequest(message?: string): createHttpError.HttpError;
+    unauthorized(message?: string): createHttpError.HttpError;
+    paymentRequired(message?: string): createHttpError.HttpError;
+    forbidden(message?: string): createHttpError.HttpError;
+    notFound(message?: string): createHttpError.HttpError;
+    methodNotAllowed(message?: string): createHttpError.HttpError;
+    notAcceptable(message?: string): createHttpError.HttpError;
+    proxyAuthenticationRequired(message?: string): createHttpError.HttpError;
+    requestTimeout(message?: string): createHttpError.HttpError;
+    conflict(message?: string): createHttpError.HttpError;
+    gone(message?: string): createHttpError.HttpError;
+    lengthRequired(message?: string): createHttpError.HttpError;
+    preconditionFailed(message?: string): createHttpError.HttpError;
+    payloadTooLarge(message?: string): createHttpError.HttpError;
+    uriTooLong(message?: string): createHttpError.HttpError;
+    unsupportedMediaType(message?: string): createHttpError.HttpError;
+    rangeNotSatisfiable(message?: string): createHttpError.HttpError;
+    expectationFailed(message?: string): createHttpError.HttpError;
+    imateapot(message?: string): createHttpError.HttpError;
+    misdirectedRequest(message?: string): createHttpError.HttpError;
+    unprocessableEntity(message?: string): createHttpError.HttpError;
+    locked(message?: string): createHttpError.HttpError;
+    failedDependency(message?: string): createHttpError.HttpError;
+    unorderedCollection(message?: string): createHttpError.HttpError;
+    upgradeRequired(message?: string): createHttpError.HttpError;
+    preconditionRequired(message?: string): createHttpError.HttpError;
+    tooManyRequests(message?: string): createHttpError.HttpError;
+    requestHeaderFieldsTooLarge(message?: string): createHttpError.HttpError;
+    unavailableForLegalReasons(message?: string): createHttpError.HttpError;
+    internalServerError(message?: string): createHttpError.HttpError;
+    notImplemented(message?: string): createHttpError.HttpError;
+    badGateway(message?: string): createHttpError.HttpError;
+    serviceUnavailable(message?: string): createHttpError.HttpError;
+    gatewayTimeout(message?: string): createHttpError.HttpError;
+    httpVersionNotSupported(message?: string): createHttpError.HttpError;
+    variantAlsoNegotiates(message?: string): createHttpError.HttpError;
+    insufficientStorage(message?: string): createHttpError.HttpError;
+    loopDetected(message?: string): createHttpError.HttpError;
+    bandwidthLimitExceeded(message?: string): createHttpError.HttpError;
+    notExtended(message?: string): createHttpError.HttpError;
+    networkAuthenticationRequired(
+      message?: string,
+    ): createHttpError.HttpError;
+
+    getHttpError: (code: number, message?: string) => string;
+    HttpError: createHttpError.HttpErrorConstructor;
+};
+
+export interface HttpErrors {
+    httpError: HttpErrorType;
+}

package.json

@@ -23,6 +23,9 @@
   },
   "homepage": "https://github.com/fastify/fastify-sensible#readme",
   "devDependencies": {
+    "@types/http-errors": "^1.6.1",
+    "@types/proxy-addr": "^2.0.0",
+    "@types/vary": "^1.1.0",
     "fastify": "^2.0.0",
     "standard": "^12.0.1",
     "tap": "^12.1.1"