Project: RSpec Expectations 2.2

Publisher: RSpec

Expect error

Expect a proc to raise an error when called.

Scenarios

Given

a file named "expect_error_spec.rb" with:

describe Object, "#non_existent_message" do
  it "should raise" do
    expect{Object.non_existent_message}.to raise_error(NameError)
  end
end

#deliberate failure
describe Object, "#public_instance_methods" do
  it "should raise" do
    expect{Object.public_instance_methods}.to raise_error(NameError)
  end
end

When

I run "rspec ./expect_error_spec.rb"

Then

the output should contain "2 examples, 1 failure"

Then

the output should contain "expected NameError but nothing was raised"

expect no error

Given

a file named "expect_no_error_spec.rb" with:

describe Object, "#public_instance_methods" do
  it "should not raise" do
    expect{Object.public_instance_methods}.to_not raise_error(NameError)
  end
end

#deliberate failure
describe Object, "#non_existent_message" do
  it "should not raise" do
    expect{Object.non_existent_message}.to_not raise_error(NameError)
  end
end

When

I run "rspec ./expect_no_error_spec.rb"

Then

the output should contain "2 examples, 1 failure"

Then

the output should contain "undefined method `non_existent_message'"

Last published over 5 years ago by dchelimsky.

Expect error

RSpec Expectations settings