This rule considers the following JSX bad:
function Foo() {
return <img alt={foo || ''} />;
}
this is also considered bad:
function Foo() {
return <img alt="" />;
}
but this is okay:
function Foo() {
return <img alt={foo} />;
}
However, I think that all three should be okay. Empty strings can be used appropriately for alt text on images that are decorative.