X_TEST_ISLAND_STATE_JSON_INVALID

an island state carries a value JSON does not

island props ride the data-x-props script tag, which is JSON.stringifyd — so a Date, a function, a Map, a cycle, a non-finite number or an undefined is not approximately right in the picture, it is a prop the component never receives. cause names the exact path

write the value the cause names as JSON — a string, a number, a boolean, null, an array or a plain object