Call custom form validator more than once

Question

I'm using a custom validator to check if the values of 2 inputs match:

import { FormGroup } from '@angular/forms';

// custom validator to check that two fields match
export function MustMatch(controlName: string, matchingControlName: string) {
    return (formGroup: FormGroup) => {
        const control = formGroup.controls[controlName];
        const matchingControl = formGroup.controls[matchingControlName];

        if (matchingControl.errors && !matchingControl.errors.mustMatch) {
            // return if another validator has already found an error on the matchingControl
            return;
        }

        // set error on matchingControl if validation fails
        if (control.value !== matchingControl.value) {
            matchingControl.setErrors({ mustMatch: true });
        } else {
            matchingControl.setErrors(null);
        }
    }
}

This works for the matching of 1 pair of inputs, implimented as below:

ngOnInit() {
        this.applicationForm = this.formBuilder.group({
            firstName: ['', Validators.required],
            password: ['', [Validators.required, Validators.minLength(6)]],
            confirmPassword: ['', Validators.required],
            acceptTerms: [false, Validators.requiredTrue]
        }, {
            validator: MustMatch('password', 'confirmPassword')
        });
    }

But I can't figure out how to enable it a second time for another pair such as email and confirm email.

Doing

validator: MustMatch('password', 'confirmPassword'), validator2: MustMatch('email', 'confirmEmail')

Doesn't error, but doesn't do anything, the validation still works for password, but not for email. You can't have multiple properties with the same name so I tried with "validator2".

I can't call a whole new

{
   validator: MustMatch('password', 'confirmPassword')
}

within this.formBuilder.group({}) as it only takes in 2 arguments.

Answer 1

From the doc, you must do this way

validators: [
               MustMatch('password', 'confirmPassword'),
               MustMatch('email', 'confirmEmail')
            ]