Example:
notEmpty({}) // produces: false
notEmpty({I: 'am not empty'}) // produces: true
notEmpty([]) // produces: false
notEmpty([1, 2, 3]) // produces: true
notEmpty('') // produces: false
notEmpty('not empty') // produces: true
notEmpty(NaN) // produces: false
notEmpty(0) // produces: true
A false result does not prove absence: '' and [] and {} are present but empty, yet the negative branch narrows as though the value were null or undefined. Guard with has/notEmpty when you want substance; compare against undefined when you only care about presence.
A value that is not empty.