Project: RSpec Mocks 3.9

Publisher: RSpec

Allowing messages

Test doubles are "strict" by default -- messages that have not been specifically
allowed or expected will trigger an error. Use allow(...).to receive(...) to configure
which messages the double is allowed to receive. You can also use allow(...).to receive_messages(...) to configure allowed messages (and return values) in bulk.

Scenarios

Allowed messages return nil by default

Given

a file named "allow_message_spec.rb" with:

RSpec.describe "allow" do
  it "returns nil from allowed messages" do
    dbl = double("Some Collaborator")
    allow(dbl).to receive(:foo)
    expect(dbl.foo).to be_nil
  end
end

When

I run rspec allow_message_spec.rb

Then

the examples should all pass

Messages can be allowed in bulk using `receive_messages`

Given

a file named "receive_messages_spec.rb" with:

RSpec.describe "receive_messages" do
  it "configures return values for the provided messages" do
    dbl = double("Some Collaborator")
    allow(dbl).to receive_messages(:foo => 2, :bar => 3)
    expect(dbl.foo).to eq(2)
    expect(dbl.bar).to eq(3)
  end
end

When

I run rspec receive_messages_spec.rb

Then

the examples should all pass

Last published 11 months ago by Jon Rowe.

Allowing messages

RSpec Mocks settings