Why is my Angular FormGroup Valid when a control that is marked as required is empty?

I am trying to setup a basic form validation for a select.

In my constructor I have the following FormGroup

this.formSubmission = new FormGroup(
  {
    triggers: new FormControl(['', [ Validators.required]])
  }
)

I have a button on the screen to test the validity of the FormGroup and it always comes back as valid even when there is nothing selected for "triggers".

When clicked the following code executes:

console.log('FormGroup Status: ' + this.formSubmission.status)

This will return VALID.

The HTML portion of this can be found here:

<div [formGroup]="formSubmission">
  <mat-form-field appearance="fill">
    <mat-label>Triggers</mat-label>
    <mat-select 
    formControlName="triggers" multiple
    >
      <mat-option *ngFor="let trigger of triggersList" [value]="trigger.TRIGGER_NAME">{{trigger.TRIGGER_NAME}}</mat-option>
    </mat-select>
  </mat-form-field>
</div>

>Solution :

You defined triggers wrong.

  triggers: new FormControl(['', [ Validators.required]])

will result in triggers: array.
First argument is the value, second is the validators, asyncValidators or options

what you probably meant to do is this:

triggers: new FormControl('', [ Validators.required])