When a search fix must survive several similar queries, testing one query at a time creates needless repetition. _.every turns that repetition into one check: give it a collection and a predicate, and it returns true only when the predicate succeeds for every element. section 15.4
Check a family of successful queries
Capture the expected search result, then test queries such as "Habit", "habit", "7 Habit", and "habits of" together. The predicate runs the search and compares each result with _.isEqual. Repeat the pattern with queries expected to return no books, such as "abit" and "bit".
