check-specific-attributes-on-activerecord-array.md

Check Specific Attributes On ActiveRecord Array

If you're writing a test against a method that returns a collection of ActiveRecord results, it can be tedious to check specific values for each. There are certainly an endless number of ways to approach those assertions.

You can keep your assertion fairly concise by using nested RSpec matchers. There are two in particular that can help with this kind of check:

books = get_books_by("David Sedaris")

expect(books).to match_array(
  [
    have_attributes(
      "title" => "Calypso",
      "publication_year" => "2018",
    ),
    have_attributes(
      "title" => "Theft By Finding",
      "publication_year" => "2017",
    ),
  ],
)

The outer part of the assertion is match_array which checks that the result is an array of a certain size with specific elements. On its own we'd have to spell out all the attributes of each book, including things like created_at and updated_at. However, by combining it with have_attributes matchers, we are able to make the assertion over a subset of each record's attributes.