Hey, some assertions seem pretty weird...

assert.strictEqual(betweenMarkers("", ""), "My new site"); - Empty and not enough arguments but answer is a whole sentence.

assert.strictEqual(betweenMarkers("No ", ">", "<"), ""); - No markers but answer is empty string

assert.strictEqual(betweenMarkers("No one", ">", "<"), "") - Again no markers but answer is empty string