Utitities

utilities used to make development easier and maximize code reusability

User Input / Form Validation

Front-End

Client side validation as we know is just as important as server side. for this Formik with Yup

import * as yup from "yup";
export const loginValidationSchema = yup.object({
  email: yup.string().email("Enter a valid email").required("Email is required."),
  password: yup
    .string()
    .min(8, "Minimum of 8 characters")
    .max(30, "Maximum of 30 characters")
    .trim()
    .required("Password field is required."),
});

import * as yup from "yup";
const formik = useFormik({
  initialValues: {
    email: "",
    password: "",
  },
  validationSchema: loginValidationSchema,
  onSubmit: loginFormSubmitHandler,
});

Back-End

On the backend, user input validation is handled by Express Validator
Different Types of validation is done in this controller

router.post(
  "/login",
  [
    body("email").trim().isEmail().normalizeEmail().withMessage("Email is Invalid"),
    body("password").trim().isLength({ min: 8, max: 30 }).withMessage("Password is Invalid"),
  ],
  postLogin
);

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Error Handling

Error Handling is handled by 1 helper function and 1 middleware to minimize the work This function returns an Error Object it is just so we can easily pass an errorMessage and errorCode rather than manually setting it after creating a new Error object.

module.exports = (errorMessage, errorCode) => {
  const newErr = new Error(errorMessage);
  newErr.statusCode = errorCode || 500;
  return newErr;
};

Usage

This is how i normally handle error and pass an error code

const foundUser = await userModel.findOne({ email: email });
if (!foundUser) {
  const newErr = new Error("Invalid Email");
  newErr.statusCode = 422;
  throw newErr;
}

With the Helper Function

const foundUser = await userModel.findOne({ email: email });
if (!foundUser) throw newError("Invalid Email", 422);

it makes handling error and attach a statusCode easy