I have the following code:
sample_code.rb
class Foo
def bar
Timeout.timeout(0.5){
puts "Interupt this if it takes longer then 0.5 seconds"
}
end
end
foo = Foo.new()
foo.bar
The example above works when you paste it in irb,
but when you place it in a script and run it like this:
ruby ./sample_code.rb
It will give the following error.
Traceback (most recent call last):
1: from ./irb_works_ruby_dont.rb:11:in `<main>'
./irb_works_ruby_dont.rb:4:in `bar': uninitialized constant Foo::Timeout (NameError)
Is this a Timeout issue? Does irb load some modules that the normal ruby command doesn't? How to make the code work when run as a script?
The most likely explaination is that IRB requires Timeout when it starts up the REPL - but your script file is being executed before that happens. You can fix it by simply requiring it:
require 'timeout'
class Foo
def bar
Timeout.timeout(0.5){
puts "Interupt this if it takes longer then 0.5 seconds"
}
end
end
foo = Foo.new
foo.bar
Related
using
rspec 2.6.4
rails 3.1.6
How to use let variables in rails test console?
1.9.3-p0 :032 > let(:user) { create(:user) }
NoMethodError: undefined method `let' for main:Object
Please advise, which library should be required here?
For example: below is executed in console to use stub methods in console.
require 'rspec/mocks/standalone'
Is it possible, to define and call let variables in rails console?
If you are fine with let just creating globals, you can polyfill it like this:
def let(name)
Object.send :instance_variable_set, "##{name}", yield
Object.send :define_method, name do
Object.send :instance_variable_get, "##{name}"
end
end
Usage is the same as rspec:
irb(main):007:0> let(:foo) { 1 }
=> :foo
irb(main):008:0> foo
=> 1
though you really shouldn't be pasting your test code into console to debug it. It's much better to use a breakpoint tool like pry or byebug.
let in rspec is not much more than a lazily executed and memoized method definition. If you must have in the irb you could define it like this:
$ cat let.rb
def let(sym)
$let ||= {}
define_method sym do
$let[sym] ||= yield
end
end
require './let in irb or place it in .irbrc and you have your rspec-like let. Note, that rspec reevaluates let in each new example (it or specify block). Since you don't have them in irb you may need to clear your let cache manually ($let = {}) to force re-evaluation.
It's fairly common in Ruby for methods that take blocks to look like this:
class File
def open(path, mode)
perform_some_setup
yield
ensure
do_some_teardown
end
end
It's also fairly idiomatic for a method to look like this:
def frobnicate
File.open('/path/to/something', 'r') do |f|
f.grep(/foo/).first
end
end
I want to write a spec for this that doesn't hit the filesystem, which ensures it pulls the right word out of the file, something like:
describe 'frobnicate' do
it 'returns the first line containing the substring foo' do
File.expects(:open).yields(StringIO.new(<<EOF))
not this line
foo bar baz
not this line either
EOF
expect(frobnicate).to match(/foo bar baz/)
end
end
The problem here is that, by mocking out the call to File.open, I've also removed its return value, which means that frobnicate will return nil. If I were to add something like File.returns('foo bar baz') to the chain, however, I'd end up with a test that doesn't actually hit any of the code I'm interested in; the contents of the block in frobnicate could do anything and the test would still pass.
How might I appropriately test my frobnicate method without hitting the filesystem? I'm not particularly attached to any particular testing framework, so if your answer is "use this awesome gem that'll do it for you" then I'm OK with that.
It seems like you just need to mock the call to File a little differently. I was getting syntax errors running your code as-is, so I'm not sure what version of RSpec you're on, but if you're on 3.x this will do the job:
frobnicate_spec.rb
gem 'rspec', '~> 3.4.0'
require 'rspec/autorun'
RSpec.configure do |config|
config.mock_with :rspec
end
def frobnicate
File.open('/path/to/something', 'r') do |f|
f.grep(/foo/).first
end
end
RSpec.describe 'frobnicate' do
it 'returns the first line containing the substring foo' do
allow(File).to receive(:open).and_call_original
allow(File).to receive(:open).and_yield StringIO.new <<-EOF
not this line
foo bar baz
not this line either
EOF
expect(frobnicate).to match(/foo bar baz/)
end
end
Invoke with ruby frobnicate_spec.rb so we can use a specified RSpec version.
Source: RSpec Mocks expecting messages and yielding responses
Using minitest it could be done like I post below. I have added the whole runnable file, so you can test it from the command line with ruby -Ilib:test test_file.rb:
def frobnicate
found_string = nil
File.open('/path/to/something', 'r') do |f|
found_string = f.grep(/foo/).first
end
found_string
end
class FrabnicateTest < Minitest::Test
def test_it_works
mock_file = StringIO.new(%(
not this line
foo bar baz
not hthis line either
))
search_result = nil
File.stub(:open, nil, mock_file) do
search_result = frobnicate
end
assert_match(/foo bar baz/, search_result)
end
end
Here is the class that I'm testing contained in Foo.rb:
class Foo
def bar
return 2
end
end
Here is the my test contained in Foo_spec.rb:
require "./Foo.rb"
describe "Foo" do
before(:all) do
puts "#{Foo == nil}"
Foo.any_instance.stub(:bar).and_return(1)
end
it "should pass this" do
f = Foo.new
f.bar.should eq 1
end
end
I am getting the following output:
false
F
Failures:
1) Foo Should pass this
Failure/Error: Foo.any_instance.stub(:bar).and_return(1)
NoMethodError:
undefined method `any_instance_recorder_for' for nil:NilClass
# ./Foo_spec.rb:6:in `block (2 levels) in <top (required)>'
Finished in 0 seconds
1 example, 1 failure
Failed examples:
rspec ./Foo_spec.rb:9 # Foo Should pass this
I've consulted the doc and the example given is passing on my machine (so it isn't a problem with the rspec code), but it isn't giving me any information on what I might be doing wrong. The error message is also quite confusing as it's telling me not to call .any_instance on a nil:NilClass, but as I proved with my output, Foo isn't nil. How am I supposed to call .any_instance.stub on my custom object?
I'm using Ruby 1.9.3 and rspec 2.14.5.
You should use before(:each) for stubbing.
Stubs in before(:all) are not supported. The reason is that all stubs and mocks get cleared out after each example, so any stub that is set in before(:all) would work in the first example that happens to run in that group, but not for any others.
rspec-mocks readme
From Rspec 3 any_instance is not defined anymore.
Now use:
allow_any_instance_of(Foo).to receive(:bar).and_return(1)
Source for this and older versions:
https://makandracards.com/makandra/2561-stub-methods-on-any-instance-of-a-class-in-rspec-1-and-rspec-2
Updating rspec worked for me. You can do it using the following command:
bundle update rspec
It's rather hard to find any documentation on Mocha, so I'm afraid I'm totally at sea here. I have found a problem with stubbing methods that pass arguments. So for instance if I set up a class like this:
class Red
def gets(*args)
#input.gets(*args)
end
def puts(*args)
#output.puts(*args)
end
def initialize
#input = $stdin
#output = $stdout
end
private
def first_method
input = gets.chomp
if input == "test"
second_method(input)
end
end
def second_method(value)
puts value
second_method(value)
end
end
Yes it's contrived, but it's a simplification of the idea that you may have a method that you don't want called in the test.
So I might write a test such as:
setup do
#project = Red.new
#project.instance_variable_set(:#input, StringIO.new("test\n"))
#project.stubs(:second_method)
end
should "pass input value to second_method" do
#project.expects(:second_method).with("test").once
#project.instance_eval {first_method}
end
Now I would expect this to pass. But instead I get this rather arcane error message:
Errno::ENOENT: No such file or directory - getcwd
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/backtrace_filter.rb:12:in `expand_path'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/backtrace_filter.rb:12:in `block in filtered'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/backtrace_filter.rb:12:in `reject'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/backtrace_filter.rb:12:in `filtered'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/expectation_error.rb:10:in `initialize'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/mockery.rb:53:in `new'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/mockery.rb:53:in `verify'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/api.rb:156:in `mocha_verify'
/Users/i0n/.rvm/gems/ruby-1.9.2-head/gems/mocha-0.9.8/lib/mocha/integration/mini_test/version_131_and_above.rb:27:in `run'
This means absolutely nothing to me, other than something deep in Mochas bowels has just gone clang. If I write the same sort of test without an argument passing to the second method I get no problem. Am I missing something?
I think it must be something in shoulda causing the problem. I use test/unit, and everything appears to be OK.
require 'rubygems'
require "test/unit"
require 'mocha'
require File.dirname(__FILE__) + '/../src/red'
class RedTest < Test::Unit::TestCase
def setup
#project = Red.new
#project.instance_variable_set(:#input, StringIO.new("test\n"))
#project.stubs(:second_method)
end
def test_description_of_thing_being_tested
#project.expects(:second_method).with("test").once
#project.instance_eval {first_method}
end
end
gives the following output:
stephen#iolanta:~/tmp/red/test # ruby red_test.rb
Loaded suite red_test
Started
.
Finished in 0.000679 seconds.
1 tests, 1 assertions, 0 failures, 0 errors
stephen#iolanta:~/tmp/red/test #
Sorry - I've only just seen this. It's better to submit bug reports to us in Lighthouse. What documentation have you found? Have you seen the RDoc on Rubyforge? What sort of documentation were you looking for that you did not find?
I've been unable to reproduce your bug. What version of Ruby, Rubygems, Shoulda & Mocha were you using?
You can see the results of me running your test in this Gist.
Know of a way to mock %[]? I'm writing tests for code that makes a few system calls, for example:
def log(file)
%x[git log #{file}]
end
and would like to avoid actually executing system calls while testing this method. Ideally I'd like to mock %x[..] and assert that the correct shell command is passed to it.
%x{…} is Ruby built-in syntax that will actually call Kernel method Backtick (`). So you can redefine that method. As backtick method returns the standard output of running cmd in a subshell, your redefined method should return something similar to that ,for example, a string.
module Kernel
def `(cmd)
"call #{cmd}"
end
end
puts %x(ls)
puts `ls`
# output
# call ls
# call ls
Using Mocha, if you want to mock to following class:
class Test
def method_under_test
system "echo 'Hello World!"
`ls -l`
end
end
your test would look something like:
def test_method_under_test
Test.any_instance.expects(:system).with("echo 'Hello World!'").returns('Hello World!').once
Test.any_instance.expects(:`).with("ls -l").once
end
This works because every object inherits methods like system and ` from the Kernel object.
I don't know of a way to mock a module, I'm afraid. With Mocha at least, Kernel.expects doesn't help. You could always wrap the calling in a class and mock that, something like this:
require 'test/unit'
require 'mocha'
class SystemCaller
def self.call(cmd)
system cmd
end
end
class TestMockingSystem < Test::Unit::TestCase
def test_mocked_out_system_call
SystemCaller.expects(:call).with('dir')
SystemCaller.call "dir"
end
end
which gives me what I'd hope for:
Started
.
Finished in 0.0 seconds.
1 tests, 1 assertions, 0 failures, 0 errors
How about logging it to a text file, or outputting it to your console?
def log(file)
puts "git log #{file}"
end
Can't you just ovverride the function with a method that returns true when it gets the command?