I'm trying to test that an error is raised correctly under certain conditions. In this spec, the error is raised, but the test still fails. What am I doing wrong?
require 'spec_helper'
describe USBTeensyRenderer do
context 'when the correct USB port name is not present' do
it 'raises an error on instantiation' do
expect(renderer = USBTeensyRenderer.new).to raise_error(USBInitError)
end
end
end
And the terminal output of 'bundle exec rspec':
Failures:
1) USBTeensyRenderer when the correct USB port name is not present raises an error on instantiation
Failure/Error: expect(renderer = USBTeensyRenderer.new).to raise_error(USBInitError)
USBInitError:
USB output couldn't be initialized
# ./lib/ivan/view/renderers/usb_teensy_renderer.rb:9:in `rescue in initialize'
# ./lib/ivan/view/renderers/usb_teensy_renderer.rb:6:in `initialize'
# ./spec/models/usb_teensy_renderer_spec.rb:10:in `new'
# ./spec/models/usb_teensy_renderer_spec.rb:10:in `block (3 levels) in <top (required)>'
Finished in 0.00351 seconds (files took 0.11638 seconds to load)
8 examples, 1 failure
Failed examples:
rspec ./spec/models/usb_teensy_renderer_spec.rb:9 # USBTeensyRenderer when the correct USB port name is not present raises an error on instantiation
Here's how the error is raised in the class:
def initialize
begin
#sp = SerialPort.new("/dev/tty.usbmodem54121", 9600, 8, 1)
rescue
raise USBInitError, "USB output couldn't be initialized"
end
#sp.get_modem_params()
end
I believe expect should take a block in this case:
expect { renderer = USBTeensyRenderer.new }.to raise_error(USBInitError)
This thread has a pretty good explanation on expect() vs expect {}
Rspec: expect vs expect with block - what's the difference?
Related
I'm trying to write specs for an extension to rspec.
This is the gist of what I'm trying to test:
require 'rspec-let-and-after-extension'
RSpec.describe "let(...).and_after" do
it 'is called if the `let` is invoked even if the example fails' do
call_order = []
RSpec.describe do
let(:foo) { }.and_after { call_order << :and_after }
it { foo; call_order << :example; raise 'failed!' }
end.run
expect(call_order).to eq [:example, :and_after]
end
end
One of the important behaviours is that if running the example fails, the cleanup code still runs. So I test this by recording the order of the calls and raising an exception from the example.
Problem is, when I run it, it sees this block as a second example, which then fails with errors:
.F
Failures:
1)
Got 0 failures and 2 other errors:
1.1) Failure/Error: it { foo; call_order << :example; raise 'failed!' }
RuntimeError:
failed!
# ./spec/spec.rb:43:in `block (4 levels) in <top (required)>'
# ./spec/spec.rb:44:in `block (2 levels) in <top (required)>'
1.2) Failure/Error: it { foo; call_order << :example; raise 'failed!' }
RuntimeError:
failed!
# ./spec/spec.rb:43:in `block (4 levels) in <top (required)>'
Finished in 0.00167 seconds (files took 0.08011 seconds to load)
2 examples, 1 failure
Failed examples:
rspec ./spec/spec.rb:43 #
As you can see, the output did have one dot, so the actual example passed. But then there is an F, because it has seen the internal example, run that, and unsurprisingly that one failed.
How do I make rspec not see this nested example as one of the examples it's supposed to run, so that this example completes with a single dot?
(If you're wondering about what the rspec devs themselves do about their tests, it looks like they use cucumber. Do they use cucumber because they couldn't figure this out either? :))
You can use the new sandboxing API (available in 3.2+).
RSpec.configure do |rspec|
rspec.around do |ex|
RSpec::Core::Sandbox.sandboxed do |config|
# re-configure any configuration defined by your extension here
# before allowing the example to run. The sandbox runs with a fresh
# config instance, which means any configuration you have set in
# `rspec-let-and-after-extension` will not apply while the example
# is running.
# config.extend MyExtensionModule
ex.run
end
end
end
I have a method that should raise a custom error with a message. When I catch the error and raise my own custom error, it is still raising and printing the backtrace of the original error. I just want the custom error and message. Code below.
Method:
def load(configs)
begin
opts = {access_token: configs['token'],
api_endpoint: configs['endpoint'],
web_endpoint: configs['site'],
auto_paginate: configs['pagination']}
client = Octokit::Client.new(opts)
repos = client.org_repos(configs['org'])
repos.each do |r|
Project.create(name: r.name)
end
rescue Octokit::Unauthorized
raise GitConfigError, "boom"
end
#rescue Octokit::Unauthorized
end
class GitConfigError < StandardError
end
My test (which is failling):
context 'with incorrect git configs' do
before do
allow(loader).to receive(:load).and_raise Octokit::Unauthorized
end
it { expect{loader.load(configs)}.to raise_error(GitConfigError, "boom" ) }
end
Test Output:
GitProjectLoader#load with incorrect git configs should raise GitConfigError with "boom"
Failure/Error: it { expect{loader.load(configs)}.to raise_error(GitConfigError, "boom" ) }
expected GitConfigError with "boom", got #<Octokit::Unauthorized: Octokit::Unauthorized> with backtrace:
# ./spec/lib/git_project_loader_spec.rb:24:in `block (5 levels) in <top (required)>'
# ./spec/lib/git_project_loader_spec.rb:24:in `block (4 levels) in <top (required)>'
# ./spec/lib/git_project_loader_spec.rb:24:in `block (4 levels) in <top (required)>'
If you intend to test the handling of the Octokit::Unauthorized error, then raise the error anywhere before the rescue kicks in. Preferably, someplace where it would actually be raised.
Something like this, for example:
before do
allow(Octokit::Client).to receive(:new).and_raise(Octokit::Unauthorized)
end
And then:
expect{ loader.load(configs) }.to raise_error(GitConfigError, "boom" )
As a side note, I would discourage enclosing all lines of your method in a begin;rescue;end structure; you should enclose only the lines from which you are expecting errors.
You are not testing your code as you think. You have mocked it out.
The line
allow(loader).to receive(:load).and_raise Octokit::Unauthorized
replaces the load method on loader with a stub which just raises the named error.
Remove your before block, and it should test your code as intended. Note as written it will make a real request via Octokit, unless you mock that out instead.
This is something that I've seen before when using RSpec Rails and I believe that I know what is happening, I just don't know how I can get around it.
To me, it appears that the following test should pass. It expects an error, and an error is raised although I assume that the source of the error is what it is tripping up on.
csv_file_spec.rb
require 'spec_helper'
RSpec.describe Cleaner::CSVFile do
context 'when CSV file does not exist' do
let(:file) { Cleaner::CSVFile.new('tmp/file-does-not-exist.csv') }
it 'raises error' do
expect(file).to raise_error
end
end
end
csv_file.rb
module Cleaner
# A CSVFile is a CSV file loaded into memory. It exposes the clean method.
class CSVFile
attr_accessor :raw
def initialize(file)
#raw = File.open(file)
end
end
end
Output
1) Cleaner::CSVFile is not valid
Failure/Error: expect(Cleaner::CSVFile.new('tmp/file-does-not-exist.csv')).to raise_error
Errno::ENOENT:
No such file or directory # rb_sysopen - tmp/file-does-not-exist.csv
# ./lib/cleaner/csv_file.rb:8:in `initialize'
# ./lib/cleaner/csv_file.rb:8:in `open'
# ./lib/cleaner/csv_file.rb:8:in `initialize'
# ./spec/csv_file_spec.rb:7:in `new'
# ./spec/csv_file_spec.rb:7:in `block (2 levels) in <top (required)>'
I can see that the CSVFile object is not able to be initialized because the file does not exist and that'll be why RSpesc can't continue the test but what can I do to get around this?
I get the feeling that there is something fundamentally wrong with my approach to testing that I'm not seeing. I'd rather delegate the error to the standard File class, and not raise my own error messages as the error is verbose enough and I'd only be duplicating effort - should I be implementing my own instead?
Thanks!
For exceptions you should use block or lambda in expect syntax:
it 'raises error' do
expect{ Cleaner::CSVFile.new('tmp/file-not-exist.csv') }.to raise_error
end
You could use stubbing also :
require 'spec_helper'
RSpec.describe Cleaner::CSVFile do
context 'when CSV file does not exist' do
it 'raises error' do
allow(described_class).to receive(:new).and_raise("File not exist")
expect { described_class.new }.to raise_error("File not exist")
end
end
end
Read match message with a string.
I have an rspec test on a pure Ruby model:
require 'spec_helper'
require 'organization'
describe Organization do
context '#is_root?' do
it "creates a root organization" do
org = Organization.new
expect { org.is_root?.to eq true }
end
end
end
My organization model looks like this:
class Organization
attr_accessor :parent
def initialize(parent = nil)
self.parent = parent
end
end
The output when running the tests:
bundle exec rspec spec/organization_spec.rb:6
Run options: include {:locations=>{"./spec/organization_spec.rb"=>[6]}}
.
Finished in 0.00051 seconds
1 example, 0 failures
When I run the test, it passes, despite the fact that the method is_root? doesn't exist on the model. I usually work in Rails, not pure Ruby, and I've never seen this happen. What is going on?
Thanks!
It should be:
expect(org.is_root?).to eq true
When you pass block to expect it is being wrapped in ExpectationTarget class (strictly speaking BlockExpectationTarget < ExpectationTarget). Since you didn't specify what you expect from this object, the block is never executed, hence no error is raised.
You are passing a block to expect, which is never being called. You can see this by setting an expectation on that block
expect { org.is_root?.to eq true }.to_not raise_error
1) Organization#is_root? creates a root organization
Failure/Error: expect { puts "HI";org.is_root?.to eq true }.to_not raise_error
expected no Exception, got #<NoMethodError: undefined method `is_root?' for #<Organization:0x007ffa798c2ed8 #parent=nil>> with backtrace:
# ./test_spec.rb:15:in `block (4 levels) in <top (required)>'
# ./test_spec.rb:15:in `block (3 levels) in <top (required)>'
# ./test_spec.rb:15:in `block (3 levels) in <top (required)>'
Or by just putting a plain raise or puts inside the block, neither of which will be called:
expect { puts "HI"; raise; org.is_root?.to eq true }
The block form is used for expecting that a piece of code raises an exception or not. The correct syntax for checking values is:
expect(org.is_root?).to eq(true)
I am writing an ATM-system-like socket/server solution. I would appreciate if someone could tell me what I'm missing. For some reason, I get the following error running my stub test suite:
# Running tests:
.E
Finished tests in 0.002411s, 829.4384 tests/s, 414.7192 assertions/s.
1) Error:
test_0001_connects_to_a_host_with_a_socket(AtmClient::connection):
NoMethodError: undefined method `new' for #<SpoofServer:0x9dce2dc #clients=[], #server=#<TCPServer:fd 5>>
/media/wildfyre/Files/Programming/KTH/progp/Atm/spec/client/SpoofServer.rb:12:in `start'
/media/wildfyre/Files/Programming/KTH/progp/Atm/spec/client/client_spec.rb:12:in `block (3 levels) in <top (required)>'
2 tests, 1 assertions, 0 failures, 1 errors, 0 skips
My minispec file is:
require_relative '../spec_helper.rb'
require_relative '../../lib/AtmClient.rb'
require_relative 'SpoofServer.rb'
describe AtmClient do
it "can be created with no arguments" do
AtmClient.new.must_be_instance_of AtmClient
end
describe 'connection' do
it "connects to a host with a socket" do
spoof = SpoofServer.new.start
client = AtmClient.new.connect
spoof.any_incoming_connection?.must_be true
spoof.kill
end
end
end
My SpoofServer file is:
require 'socket'
class SpoofServer
def initialize
end
def start
#clients = []
#server = TCPServer.new 1234
#listener_thread = new Thread do
#clients.add #server.accept
end
end
def any_incoming_connection?
#clients.size > 0
end
def kill
#listener_thread.exit
#clients.each {|c| c.close}
end
end
As you can read in the trace of the calls stack:
NoMethodError: undefined method `new' for #<SpoofServer:...>
/.../spec/client/SpoofServer.rb:12:in `start'
The error is inside the start method defined in SpoofServer.rb, at line 12, the wrong line is:
#listener_thread = new Thread do
That should be:
#listener_thread = Thread.new do
As you have written it, what you are actually doing is to calling the new method passing the Thread class as argument. Since no new method is defined for instances of the SpoofServer class you get the NoMethodError exception.
In body of instance method SpoofServer#start, you can't call the class method SpoofServer.new by new.