[Fixed] Express Validator – Only allow letters, numbers and some special characters

Issue

With JavaScript on the front end, I created regex that allows letters, numbers and some special characters like so….

    function onlyAlphaSomeChar(value) {
      const re = /^[A-Za-z0-9 .,'!&]+$/;
      return re.test(value);
   }

what would be the equivalent of this if I were to build the validation process with express-validator on the backend?

I have this much created within my ExpressJs environment, but not sure what next steps should look like…

//...

app.post('/', [
    //VALIDATE
    check('comment')
        .notEmpty()
        .withMessage('Comment required')
        .isLength({min: 3,max:280})       
        .withMessage('Comment must be between 3 and 280 characters')
        .escape()
], (req, res) => {

//...

});

Solution

To check against a regular expression, you can use .match(regexp).

Thus, here, you could do:

//...

app.post('/', [
    //VALIDATE
    check('comment')
        .escape()
        .notEmpty()
        .withMessage('Comment required')
        .isLength({min: 3,max:280})       
        .withMessage('Comment must be between 3 and 280 characters')
        .matches(/^[A-Za-z0-9 .,'!&]+$/)
], (req, res) => {

//...

});
```

Does this answer your question?