Express Helper

Express helper is a plugin that saves logic when writing applications using express.

Installation

npm i @loksly/expresshelper

Usage

import { expresshelper, ResponseHelper } from "@loksly/expresshelper";

/* ... */

app.use(expresshelper());

/* or you may customize
app.use(expresshelper({
    logger: console,
    enableJSONP: false;
    shouldSend404onEmpty: true;
}));
*/

app.get("/api/v1/pizzas/:id", (req, res: ResponseHelper) => {
    if (typeof req.params.id === "string") {
        res.locals.expresshelper.promiseWrapper(pizzas.findOne(id));
    } else {
        res.locals.expresshelper.promiseWrapper(pizzas.find(id));
    }
});

app.put("/api/v1/pizzas/:id", (req, res) => {
    if (typeof req.params.id === "string") {
        res.locals.expresshelper.promiseWrapper(pizzas.findOne(id));
    } else {
        res.locals.expresshelper.missingParameter("id");
    }
});

app.listen(3000, "localhost", () => console.log("Listening on http://localhost:3000"));

Now you can the expected output for your application is:

curl http://localhost:3000/pizzas # outputs the whole list of pizzas
curl http://localhost:3000/pizzas/nonexistingId # outputs 404 status code (not found error), body `{ "error": "An error has occurred", "details": "Not found" }`
curl http://localhost:3000/pizzas/existingId # outputs a single pizza element
curl -X PUT http://localhost:3000/pizzas/ # outputs 400 status code (Bad Request Error), body: `{ "error": "Missing parameter", "details": "id" }`

API

• callbackErrorHelper(err: any): void
• cb(err: any, value: any): void
• cbWithDefaultValue(defaultValue: any): (err: any) => void
• errorHelper(errCode?: number | string, defaultMessage?: undefined | string): (err: any) => void
• forbiddenHelper(details: any): void
• missingParameterHelper(parametername: string): void
• notFoundHelper(): void
• notImplementedHelper(): void
• okHelper(shouldSend404onEmpty?: undefined | false | true): (data: any) => void
• okHelperWithDefaultValue(defaultvalue: any, statusCode?: undefined | number): (data: any) => void
• promiseWrapper(promise: Promise<any>, shouldSend404onEmpty?: undefined | false | true): void
• send(content: any, statusCode?: undefined | number): void
• unauthenticatedHelper(details: any): void
• unauthorizedHelper(details: any): void

For examples of usage you should check the tests.