Hooks

RSpec hooks are special methods that run at specific points during the execution of RSpec test suite. They provide a way to run code before or after certain events, such as before or after each example, before or after each describe block, or before or after the entire suite.

Here are the basics of using RSpec hooks:

1. Before hooks: A before hook is a block of code that runs before each example in a group (describe block). It can be used to set up the necessary test data, establish connections to external services or databases, or perform any other setup that needs to be done before running the test. To use a before hook, simply define a method called before and pass a block of code to it.

Example:

rubyCopy codedescribe "some feature" do
  before do
    @foo = Foo.new
  end

  it "should do something" do
    expect(@foo.do_something).to eq("something")
  end
end

In the above example, the before hook sets up an instance variable @foo before each example is run. This allows the example to use the @foo variable without having to create a new instance of Foo for each example.

2. After hooks: An after hook is a block of code that runs after each example in a group. It can be used to clean up any resources used during the test or to perform any other necessary cleanup. To use an after hook, define a method called after and pass a block of code to it.

Example:

rubyCopy codedescribe "some feature" do
  after do
    # clean up any resources used during the test
  end

  it "should do something" do
    # test code here
  end
end

In the above example, the after hook is defined to clean up any resources used during the test.

3. Around hooks: An around hook is a block of code that runs before and after each example in a group. It can be used to modify the behavior of the test or to wrap the test in a transaction. To use an around hook, define a method called around and pass a block of code to it.

Example:

rubyCopy codedescribe "some feature" do
  around do |example|
    # run before each example
    # example.run runs the example
    # run after each example
  end

  it "should do something" do
    # test code here
  end
end

In the above example, the around hook is defined to run before and after each example in the group.

4. Hooks for entire suite: RSpec also provides hooks that run before and after the entire test suite. These hooks can be used to set up global test configuration or to perform any necessary cleanup after the test suite has run.

Example:

rubyCopy codeRSpec.configure do |config|
  config.before(:suite) do
    # run before the entire test suite
  end

  config.after(:suite) do
    # run after the entire test suite
  end
end

In the above example, the before(:suite) and after(:suite) hooks are defined to run before and after the entire test suite, respectively.

These are the basics of using RSpec hooks. Hooks are a powerful feature of RSpec that allow you to set up and tear down test data and resources, and modify the behavior of tests. By using hooks, you can write more maintainable and flexible tests.