express-tguard 💂‍♀️

Minimalistic request validation middleware for express, with properly typed request object. Based on the widely popular tguard library.

Installation

npm install express-tguard

or

yarn add express-tguard

Example Usage

import express from "express";
import {
  validateSchema,
  RequestSchema,
  TString,
  TNumber,
  TArray,
} from "express-tguard";

const app = express();

app.post(
  "/users/:id",
  validateSchema(
    {
      params: { id: TString },
      body: { name: TString, age: TNumber, posts: TArray(TString) },
    },
    (req, res) => {
      // Now all validated types are available on the request object:
      const questions = req.body.posts.filter((post) => post.endsWith("?"));
      // typeof questions === string[]
      req.sendStatus(200);
    }
  )
);

validateSchema(schema: RequestSchema, handler?: RequestHandler): RequestHandler

validateSchema accepts a RequestSchema (learn more about Schemas), and optionally a RequestHandler. This will be called if the request was valid.

If handler wasn't provided, than the next() function would be called.

When the request was invalid, it will respond with 400 Bad Request, and an error message in the body. For example:

{
  "error": "Validation failed: Missing value at \"body.name\", expected type: string"
}

tguard

Every other name were just re-exported from tguard, to learn more about Guards, Validators (TSomething values), or how to reuse these type definitions: check out the documentation.