Function passed to withSelect not executed

This is inside the js of my block (which gets executed) trying to load data with withSelect. But the code bellow doesen’t get executed. Any idea why?

const test = withSelect( (select) => {
        console.log("test123"); /* <- no reaction inside the console*/
        return {posts: select( 'core' ).getEntityRecords( 'postType', 'post' )};
    }
);

example: https://github.com/WordPress/gutenberg/tree/master/packages/core-data