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|
Feature: Replacing classes with fakes
Bogus is an opinionated piece of software. One of the opinions we have is that you should use dependency injection to make your code more modular and your classes easier to compose. However, we respect the fact, that this is currently not very popular among Ruby developers.
In order to make life easier for people who choose not to use Dependency Injection, Bogus makes it convenient to replace chosen classes in your tests with fakes.
All you need to do, is put the following code in your describe:
fake_class(FooBar, foo: "bar")
Which is a shortcut for:
before do
fake_class(FooBar, foo: "bar")
end
Background:
Given a file named "app.rb" with:
"""ruby
require "yaml"
class Library
FILE = "library.yml"
def self.books
YAML.load_file(FILE)
end
end
class BookIndex
def self.by_author(author)
Library.books.select{|book| book[:author] == author}
end
end
"""
And a file named "spec_helper.rb" with:
"""ruby
require 'bogus/rspec'
require_relative 'app'
"""
Scenario: Replacing classes and contracts
Given a file named "library_spec.rb" with:
"""ruby
require_relative 'spec_helper'
require 'fileutils'
describe Library do
verify_contract(:library)
it "reads the books from the yaml file" do
books = [{name: "Tom Sawyer", author: "Mark Twain"},
{name: "Moby Dick", author: "Herman Melville"}]
File.open(Library::FILE, "w") { |f| f.print books.to_yaml }
expect(Library.books).to eq(books)
end
after do
FileUtils.rm_rf(Library::FILE)
end
end
"""
And a file named "book_index_spec.rb" with:
"""ruby
require_relative 'spec_helper'
describe BookIndex do
verify_contract(:book_index)
it "returns books written by author" do
tom_sawyer = {name: "Tom Sawyer", author: "Mark Twain"}
moby_dick = {name: "Moby Dick", author: "Herman Melville"}
fake_class(Library, books: [tom_sawyer, moby_dick])
expect(BookIndex.by_author("Mark Twain")).to eq([tom_sawyer])
end
end
"""
When I run `rspec book_index_spec.rb library_spec.rb`
Then the specs should pass
Scenario: Replacing classes and contracts with a different fake name
Given a file named "library_spec.rb" with:
"""ruby
require_relative 'spec_helper'
require 'fileutils'
describe Library do
verify_contract(:book_repository)
it "reads the books from the yaml file" do
books = [{name: "Tom Sawyer", author: "Mark Twain"},
{name: "Moby Dick", author: "Herman Melville"}]
File.open(Library::FILE, "w") { |f| f.print books.to_yaml }
expect(Library.books).to eq(books)
end
after do
FileUtils.rm_rf(Library::FILE)
end
end
"""
And a file named "book_index_spec.rb" with:
"""ruby
require_relative 'spec_helper'
describe BookIndex do
verify_contract(:book_index)
it "returns books written by author" do
tom_sawyer = {name: "Tom Sawyer", author: "Mark Twain"}
moby_dick = {name: "Moby Dick", author: "Herman Melville"}
fake_class(Library, fake_name: :book_repository,
books: [tom_sawyer, moby_dick])
expect(BookIndex.by_author("Mark Twain")).to eq([tom_sawyer])
end
end
"""
When I run `rspec book_index_spec.rb library_spec.rb`
Then the specs should pass
Scenario: Replacing classes with a macro
Given a file named "book_index_spec.rb" with:
"""ruby
require_relative 'spec_helper'
describe BookIndex do
fake_class(Library, books: [])
it "returns books written by author" do
expect(BookIndex.by_author("Mark Twain")).to eq([])
end
end
"""
When I run `rspec book_index_spec.rb`
Then the specs should pass
|
