@phoenix35/express-async-methods
My own take at making express compatible with async functions.
Heavily inspired by
@awaitjs/express
and @root/async-router.
Most credits go to them.
How to use
addAsync
addAsync(
app[, methods ]
);
The default methods that this adds support to
methods = [ "use", "delete", "get", "head", "param", "patch", "post", "put" ]If you don't use a router, wrap your express app with this.
const express = require("express");
const { addAsync } = require("@phoenix35/express-async-methods");
const app = addAsync(express());
// Supports error-handling middleware
app.useAsync(async (err, req, res, next) => {
await asyncLog(err.stack);
res.status(500).send("Something broke!");
});
// Supports any routing
app.getAsync("/users/:userId", async (req, res) => {
const userInfo = await dbFetch({ user: req.params.userId });
res.json(userInfo);
});Router
Router(
[[ options, ] methods ]
)
options is the options object you would pass to the creation of the router instance
See addAsync for the default methods.
If you want to use a router, import the async-ready version.
const express = require("express");
const { Router } = require("@phoenix35/express-async-methods");
const app = express(); // This app isn't async friendly.
const router = Router(); // But this router is.
router.getAsync("/i-am-error", async (req, res) => {
await new Promise(resolve => {
setTimeout(resolve, 100);
});
throw new Error("You summoned an error, you devil!");
});
app.use(router);wrap
If you want granular control, you can wrap individual callback functions.
(NOT for app.param, see below).
const express = require("express");
const { wrap } = require("@phoenix35/express-async-methods");
const app = express();
app.put("/users/:userId", wrap(async (req, res) => {
await dbUpdate({ user: req.params.userId, newInfo: req.body });
res.sendStatus(204);
}));
// Regular methods can still be used without wrapping
app.get("/users/:userId", (req, res, next) => {
dbFetch({ user: req.params.userId }, (err, userInfo) => {
if (err)
return next(err);
res.json(userInfo);
})
});wrapParam
Because of the specific signature of app.param, use wrapParam instead.
const express = require("express");
const { wrap, wrapParam } = require("@phoenix35/express-async-methods");
const app = express();
app.param("userId", wrapParam(async (req, res, next, id) => {
const userInfo = await dbFetch({ user: id });
if (userInfo == null) {
throw new TypeError("Failed to load user");
// next will be called automatically
}
req.user = userInfo;
// next will be called automatically
}));
app.put("/users/:userId", wrap(async (req, res) => {
await dbUpdate({ user: req.user.id, newInfo: req.body });
res.sendStatus(204);
}));Note that app.paramAsync and Router.paramAsync are properly created and handled by default.