Remix: middleware pattern to run code before loader on every request? - javascript

Is there a recommended pattern in Remix for running common code on every request, and potentially adding context data to the request? Like a middleware? A usecase for this might be to do logging or auth, for example.
The one thing I've seen that seems similar to this is loader context via the getLoadContext API. This lets you populate a context object which is passed as an arg to all route loaders.
It does work, and initially seems like the way to do this, but the docs for it say...
It's a way to bridge the gap between the adapter's request/response API with your Remix app
This API is an escape hatch, it’s uncommon to need it
...which makes me think otherwise, because
This API is explicitly for custom integrations with the server runtime. But it doesn't seem like middlewares should be specific to the server runtime - they should just be part of the 'application' level as a Remix feature.
Running middlewares is a pretty common pattern in web frameworks!
So, does Remix have any better pattern for middleware that runs before every loader?

Instead of middleware, you can call a function directly inside the loader, this will also be more explicit. If you want to early return a response from those "middlewares" Remix let you throw the response object.
For example, if you wanted to check the user has a certain role you could create this function:
async function verifyUserRole(request: Request, expectedRole: string) {
let user = await getAuthenticatedUser(request); // somehow get the user
if (user.role === expectedRole) return user;
throw json({ message: "Forbidden" }, { status: 403 });
}
And in any loader call it this way:
let loader: LoaderFunction = async ({ request }) => {
let user = await verifyUserRole(request, "admin");
// code here will only run if user is an admin
// and you'll also get the user object at the same time
};
Another example could be to require HTTPS
function requireHTTPS(request: Request) {
let url = new URL(request.url);
if (url.protocol === "https:") return;
url.protocol = "https:";
throw redirect(url.toString());
}
let loader: LoaderFunction = async ({ request }) => {
await requireHTTPS(request);
// run your loader (or action) code here
};

There is no way inside Remix to run code before loaders.
As you found out, there is the loader context but it runs even before remix starts to do its job (so you won't know which route modules are matched for example).
You can also run arbitrary code before handing the request to remix in the JS file where you use the adapter for the platform you're deploying to (this depend on the starter you used. This file doesn't exist if you've chosen remix server as your server)
For now it should work for some use cases, but I agree this is a missing feature in remix for now.

Inside app/root.tsx
export let loader: LoaderFunction = ({ request }) => {
const url = new URL(request.url);
const hostname = url.hostname;
const proto = request.headers.get("X-Forwarded-Proto") ?? url.protocol;
url.host =
request.headers.get("X-Forwarded-Host") ??
request.headers.get("host") ??
url.host;
url.protocol = "https:";
if (proto === "http" && hostname !== "localhost") {
return redirect(url.toString(), {
headers: {
"X-Forwarded-Proto": "https",
},
});
}
return {};
};
Source: https://github.com/remix-run/remix-jokes/blob/8f786d9d7fa7ea62203e87c1e0bdaa9bda3b28af/app/root.tsx#L25-L46

here is my middlewares implementation for remix with typescript,it's works well
ctx.return(something)=== useLoaderData()
import compose from '#utils/compose';
export default function Index() {
const ctx = useLoaderData();
return <div>{ctx.name}</div>;
}
type DefaultCtx = {
name: string;
} & Request;
export const loader =(...args)=>compose<DefaultCtx>(
async (ctx, next) => {
ctx.name = 'first';
await next();
},
async (ctx, next) => {
ctx.name = 'secnod';
await next();
},
async (ctx, next) => {
ctx.name = 'third';
ctx.return(ctx);
await next();
}
)(args);
compose is same as koa;
here is the compose's implementation
type Next = () => Promise<void>;
type Context = {};
type Middle<T = {}> = (ctx: Context & T, next: Next) => void;
const compose = <T>(...middlewares: Middle<T>[]) => {
return middlewares.reverse().reduce(
(dispatch, middleware) => {
return async ctx =>
middleware(ctx, async () => dispatch(ctx, async () => {}));
},
async () => {}
);
};
export type Middleware<T = {}, P = unknown> = (
ctx: Context & T & { return: (param: P) => void },
next: Next
) => void;
const returnEarly: Middleware = async (ctx, next) => {
return new Promise<any>(async resolve => {
ctx.return = resolve;
await next();
});
};
const componseWithReturn = <T>(...middlewares: Middleware<T>[]) =>
compose(returnEarly, ...middlewares) as (ctx: T) => void;
export default componseWithReturn;

Related

NextJS - TypeError: res.unstable_revalidate is not a function

I try to use a brand new feature released in NextJS v.12.1 https://deepinder.me/nextjs-on-demand-isr. The API itself works fine. I can reach it. But in exchange it returns 500 error that says res.unstable_revalidate is not a function. It does not work either over dev (next server && next dev) run or production one (next build && next start).
This is the api endpoint:
// ./api/misc/revalidate
const revalidateCache = async (_, res) => {
console.log(res.unstable_revalidate, 'TEST REVALIDATE'); // res.unstable_revalidate is undefined here :(
try {
await res.unstable_revalidate('/');
return res.json({ revalidated: true });
} catch (err) {
return res.status(500).send(`Error revalidating: ${err}`);
}
};
export default revalidateCache;
This is the invoke:
// ./apps/client/services/server
const getRevalidate = async () => {
await fetch('/api/misc/revalidate');
};
export default getRevalidate;
View layer that I call from:
// .src/pages/index.js
// ...some code here
const HomePage = ({ page, legacy }) => {
const handleClick = () => {
getRevalidate();
};
return (
<div className={styles.homeRoot}>
<button onClick={handleClick}>REVALIDATE</button>
</div>
);
};
UPD:
I use express to handle API abstration.
import express from 'express';
import revalidateCacheApi from './api/misc/revalidate';
export default app => {
// ...some code here
app.use('/api/misc/revalidate', revalidateCacheApi);
};
NVM. It was an issue with my local server. I use advanced set up with two independent instances (:3000 and :4000) spinning in the memory.
The way I designed API above suppose to call it over :4000 server. Which is in fact Express server (obviously does not has NextJS internal API to purge the cache).
So I moved the call to the pages/api/revalidate and up to :3000 server.
Works fine:
// ./src/pages/server/revalidate.js
const getRevalidate = async () => {
await fetch('/api/revalidate');
};
export default getRevalidate;

How to validate GitHub webhook with Deno?

I'm trying to make a GitHub webhook server with Deno, but I cannot find any possible way to do the validation.
This is my current attempt using webhooks-methods.js:
import { Application } from "https://deno.land/x/oak/mod.ts";
import { verify } from "https://cdn.skypack.dev/#octokit/webhooks-methods?dts";
const app = new Application();
app.use(async (ctx, next) => {
try {
await next();
} catch (_err) {
ctx.response.status = 500;
}
});
const secret = "...";
app.use(async (ctx) => {
const signature = ctx.request.headers.get("X-Hub-Signature-256");
if (signature) {
const payload = await ctx.request.body({ type: "text" }).value;
const result = await verify(secret, payload, signature);
console.log(result);
}
ctx.response.status = 200;
});
The verify function is returning false every time.
Your example is very close. The GitHub webhook documentation details the signature header schema. The value is a digest algorithm prefix followed by the signature, in the format of ${ALGO}=${SIGNATURE}:
X-Hub-Signature-256: sha256=d57c68ca6f92289e6987922ff26938930f6e66a2d161ef06abdf1859230aa23c
So, you need to extract the signature from the value (omitting the prefix):
const signatureHeader = request.headers.get("X-Hub-Signature-256");
const signature = signatureHeader.slice("sha256=".length);
Update: Starting in release version 3.0.1 of octokit/webhooks-methods.js, it is no longer necessary to manually extract the signature from the header — that task is handled by the verify function. The code in the answer has been updated to reflect this change.
Here's a complete, working example that you can simply copy + paste into a project or playground on Deno Deploy:
gh-webhook-logger.ts:
import { assert } from "https://deno.land/std#0.177.0/testing/asserts.ts";
import {
Application,
NativeRequest,
Router,
} from "https://deno.land/x/oak#v11.1.0/mod.ts";
import type { ServerRequest } from "https://deno.land/x/oak#v11.1.0/types.d.ts";
import { verify } from "https://esm.sh/#octokit/webhooks-methods#3.0.2?pin=v106";
// In actual usage, use a private secret:
// const SECRET = Deno.env.get("SIGNING_SECRET");
// But for the purposes of this demo, the exposed secret is:
const SECRET = "Let me know if you found this to be helpful!";
type GitHubWebhookVerificationStatus = {
id: string;
verified: boolean;
};
// Because this uses a native Request,
// it can be used in other contexts besides Oak (e.g. `std/http/serve`):
async function verifyGitHubWebhook(
request: Request,
): Promise<GitHubWebhookVerificationStatus> {
const id = request.headers.get("X-GitHub-Delivery");
// This should be more strict in reality
assert(id, "Not a GH webhhok");
const signatureHeader = request.headers.get("X-Hub-Signature-256");
let verified = false;
if (signatureHeader) {
const payload = await request.clone().text();
verified = await verify(SECRET, payload, signatureHeader);
}
return { id, verified };
}
// Type predicate used to access native Request instance
// Ref: https://github.com/oakserver/oak/issues/501#issuecomment-1084046581
function isNativeRequest(r: ServerRequest): r is NativeRequest {
// deno-lint-ignore no-explicit-any
return (r as any).request instanceof Request;
}
const webhookLogger = new Router().post("/webhook", async (ctx) => {
assert(isNativeRequest(ctx.request.originalRequest));
const status = await verifyGitHubWebhook(ctx.request.originalRequest.request);
console.log(status);
ctx.response.status = 200;
});
const app = new Application()
.use(webhookLogger.routes())
.use(webhookLogger.allowedMethods());
// The port is not important in Deno Deploy
await app.listen({ port: 8080 });

Why would a query param be undefined in NextJS?

I'm calling a page withRouter(Page) and expect the variable for the page (the page is called [category].js) to be present on initial page load. Query itself is there, the key is there, but the value is 'undefined.' There seem to be a few calls to getInitialProps on the server side with 2/3 being undefined.
The react component has a constructor, etc. it's not a functional component.
This is my current getInitialProps:
Category.getInitialProps = async ({ req, query }) => {
let authUser = req && req.session && req.session.authUser
let categoryData = {}
let categoryItemData = {}
let category = query.category
if(category){
let res = await fetch(url1,
{
method: 'POST',
credentials: 'include',
})
categoryData = await res.json();
let categoryItemsRes = await fetch(url2,
{
method: 'POST',
credentials: 'include',
})
categoryItemData = await categoryItemsRes.json();
}
return { query, authUser, categoryData, categoryItemData }
}
This might be redundant at this point, but I ran into this as well and found the docs explain this here
During prerendering, the router's query object will be empty since we do not have query information to provide during this phase. After hydration, Next.js will trigger an update to your application to provide the route parameters in the query object.
You might try this instead:
export async function getServerSideProps(ctx) {
const { id } = ctx.query;
return {
props: {
id,
},
};
}
This way it gets the query params when rendering server side, so they're instantly available.
For others who use express custom server, to fix the undefined params, we have to set the dynamic route at server.js as follow:
# server.js
...
app.prepare().then(() => {
const server = express();
....
server.get('/product/:category', (req, res) => {
const { category } = req.params;
return app.render(req, res, `/product/${category}`, req.query)
})
...
}
And then, as Valentijn answers, we can get the category params.
# pages/product/[category].js
....
export async function getServerSideProps(ctx) {
const {category} = ctx.params;
return {
props: {
category
},
};
};
...
The key is dynamic path /product/${category}. Don't use /product/:category

FeathersJS: Injecting HTTP headers in Service Test

In a feathersJS service, I have a before hook being ran that expects a certain HTTP header to exist:
src/services/service_name/service_name.hooks.js
const validationHook = () => (context, next) => {
if (!context.params.headers.hasOwnProperty('header-wanted'))
throw new errors.BadRequest();
next(null, context);
};
module.exports = {
before: {
all: [cronValidationHook()],
...
..
.
When testing this service in a generated test file from feathers-cli, however, I haven't found a way to inject headers prior to the before hook being called. The test in question is:
test/services/service_name.test.js
describe('get', () => {
it('should run "id" endpoint', async () => {
const service = app.service('v1/cron');
const resp = await service.get('id', params);
// Assertions exist after this call
});
});
Is there a way to do this that does not require utilizing an HTTP call via node-fetch or requests?
params will be whatever you pass. Just set params.headers to what you would like to test, e.g.
const getParams = {
...params,
headers: { 'header-wanted': 'something' }
};
const resp = await service.get('id', getParams);

How to mock es6 class using Jest

I am attempting to mock a class Mailer using jest and I can't figure out how to do it. The docs don't give many examples of how this works. The process is the I will have a node event password-reset that is fired and when that event is fired, I want to send an email using Mailer.send(to, subject, body). Here is my directory structure:
project_root
-- __test__
---- server
------ services
-------- emails
---------- mailer.test.js
-- server
---- services
------ emails
-------- mailer.js
-------- __mocks__
---------- mailer.js
Here is my mock file __mocks__/mailer.js:
const Mailer = jest.genMockFromModule('Mailer');
function send(to, subject, body) {
return { to, subject, body };
}
module.exports = Mailer;
and my mailer.test.js
const EventEmitter = require('events');
const Mailer = jest.mock('../../../../server/services/emails/mailer');
test('sends an email when the password-reset event is fired', () => {
const send = Mailer.send();
const event = new EventEmitter();
event.emit('password-reset');
expect(send).toHaveBeenCalled();
});
and finally my mailer.js class:
class Mailer {
constructor() {
this.mailgun = require('mailgun-js')({
apiKey: process.env.MAILGUN_API_KEY,
domain: process.env.MAILGUN_DOMAIN,
});
}
send(to, subject, body) {
return new Promise((reject, resolve) => {
this.mailgun.messages().send({
from: 'Securely App <friendly-robot#securelyapp.com>',
to,
subject: subject,
html: body,
}, (error, body) => {
if (error) {
return reject(error);
}
return resolve('The email was sent successfully!');
});
});
}
}
module.exports = new Mailer();
So, how do I successfully mock and test this class, using Jest? Many thanks for helping!
You don't have to mock your mailer class but the mailgun-js module. So mailgun is a function that returns the function messages that return the function send. So the mock will look like this.
for the happy path
const happyPath = () => ({
messages: () => ({
send: (args, callback) => callback()
})
})
for the error case
const errorCase = () => ({
messages: () => ({
send: (args, callback) => callback('someError')
})
})
as you have this 2 cases it make sense to mock the module inside your test. First you have to mock it with a simple spy where we later can set the implementation for our cases and then we have to import the module.
jest.mock('mailgun-js', jest.fn())
import mailgun from 'mailgun-js'
import Mailer from '../../../../server/services/emails/mailer'
As your module uses promises we have 2 options either return the promise from the test or use async/await. I use the later one for more info have a look here.
test('test the happy path', async() => {
//mock the mailgun so it returns our happy path mock
mailgun.mockImplementation(() => happyPath)
//we need to use async/awit here to let jest recognize the promise
const send = await Mailer.send();
expect(send).toBe('The email was sent successfully!')
});
If you would like to test that the mailgun send method was called with the correct parameter you need to adapt the mock like this:
const send = jest.fn((args, callback) => callback())
const happyPath = () => ({
messages: () => ({
send: send
})
})
Now you could check that the first parameter for send was correct:
expect(send.mock.calls[0][0]).toMatchSnapshot()
Just for Googlers and future visitors, here's how I've setup jest mocking for ES6 classes.
I also have a working example at github, with babel-jest for transpiling the ES module syntax so that jest can mock them properly.
__mocks__/MockedClass.js
const stub = {
someMethod: jest.fn(),
someAttribute: true
}
module.exports = () => stub;
Your code can call this with new, and in your tests you can call the function and overwrite any default implementation.
example.spec.js
const mockedClass = require("path/to/MockedClass")();
const AnotherClass = require("path/to/AnotherClass");
let anotherClass;
jest.mock("path/to/MockedClass");
describe("AnotherClass", () => {
beforeEach(() => {
mockedClass.someMethod.mockImplementation(() => {
return { "foo": "bar" };
});
anotherClass = new AnotherClass();
});
describe("on init", () => {
beforeEach(() => {
anotherClass.init();
});
it("uses a mock", () => {
expect(mockedClass.someMethod.toHaveBeenCalled();
expect(anotherClass.settings)
.toEqual(expect.objectContaining({ "foo": "bar" }));
});
});
});

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