TypeScript - incorrect semicolon added to method with ECMAScript 6 arrow syntax

Example of method declaration in a class.

receiveBroadcast = (message: string): void => { this.broadcastMessage = message; };

Prettier added the semicolon at the end of the method. I’ve confirmed this by flipping the semi setting to false and observing the result.

[CiGit]

You have to put those semi in a case like:

class {
	b:()=>1;
	[computedMethodName](){}
}

I think it’s not the case with a block statement tho.

[CiGit]

Why is that incorrect? This is an assignment expression.