I am following Lynda tutorial on Rspec. I was solving one of the challenges but something seems not to be working.
My file structure is:
food_finder/lib/support/number_helper.rb
food_finder/spec/support/number_helper_spec.rb
My number_helper.rb looks like:
module NumberHelper
def number_to_currency(number, options={})
#some_code
end
end
and number_helper_spec.rb is:
describe 'NumberHelper' do
include NumberHelper
describe '#number_to_currency' do
#some_test_code
end
end
on executing form food_finder directory:
rspec spec/support/number_helper_spec.rb
I get error:
in `block in ': uninitialized constant NumberHelper
(NameError)
Your code was fine. The module should be loaded with include NumberHelper, not require 'support/number_helper'. The problem came from not running rspec --init from the app's root, so none of the configuration in spec_helper.rb got loaded.
Regarding the comments mentioning Rails' number_to_currency method, the module being loaded in this exercise is modeled after the Rails version, but is self-contained:
number_helper.rb
# This module illustrates how additional functionality can be
# included (or "mixed-in") to a class and then reused.
# Borrows heavily from Ruby on Rails' number_to_currency method.
module NumberHelper
def number_to_currency(number, options={})
unit = options[:unit] || '$'
precision = options[:precision] || 2
delimiter = options[:delimiter] || ','
separator = options[:separator] || '.'
...
Related
I've been looking all around and didn't found any kind of answer to the problem i'm facing in Ruby. I'm writing an app that use core modules sets that are available in different versions. If I'm sourcing a core set version after an another one both code version will be sourced at the same and will clash with each other. That is quite normal and I'm ok with this.
One approach could be to unload the previous version to load the new one but I'd like to keep all the ones loaded into specific namespaces (to avoid time consuming to unload/reload code all the time). 2 possible solutions to me (or maybe other)
Either source the code then move it into a version namespace (some clues to do it see below but doesn't work yet)
Or source the code directly into a version namespace (don't know how to do it exactly, maybe with module_eval but need to recode the require process with dependencies). Does any solution seems possible ?
Here is a very simple poc of what I'm trying to achieve
file : coreset_1.0.0.rb
module CoreA
def self.who_am_i?; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.who_am_i?; self.to_s; end
end
file : coreset_2.0.0.rb (got some changes)
module CoreA
def self.my_name; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.my_name; self.to_s; end
end
file : coreManager.rb
module CoreManager
def self.load_version(arg_version)
#Create a module set for the selected version
core_set_name = CoreSet + '_' + arg_version.gsub('.', '_')
core_set = eval("Module #{core_set_name}; end; #{core_set_name}"
#Load the requested code
require "coreset_#{arg_version}.rb"
#Move loaded code into it core set module
core_set.const_set(:CoreA, Object.send(:remove_const, :CoreA))
core_set.const_set(:CoreB, Object.send(:remove_const,:CoreB))
#Return the created core set
core_set
end
end
If running the code :
require 'coreManager.rb'
core_set = CoreManager.load_version("1.0.0")
puts core_set::CoreA.who_am_i?
puts core_set::CoreA.get_coreB
it returns :
CoreA #not CoreSet_1_0_0::CoreA
uninitialized constant CoreA::CoreB (NameError)
If running something statically defined, it works
module CoreSet
module CoreA
def self.who_am_i?; self.to_s; end
def self.get_coreb; CoreB end
end
module CoreB
def self.who_am_i?; self.to_s; end
end
end
CoreSet::CoreA.get_coreb
It returns as expected :
CoreSet::CoreB
Depite of what is usually said :"a module is a constant", it seems to be more than that. What are the differencies and how to make the dynamic version working ?
Any other ideas ?
Thanks for your help folks :)
There are several things broken in your code (which is ok for POC, I guess), but the main one is that require loads constants and globals into the global namespace.
So, your Core<X> modules are not namespaced this way, as you might expect. There is Kernel#load method that allows "wrapped" execution of the loaded file, but it's wrapped into an anonymous module, so you can prevent the global namespace from being polluted, but you cannot "target" the constants to be defined into a particular namespace this way.
What you could try is to load the code as text and then eval it within the dynamically created module, matching your version. For example, look at this quick and very dirty sketch (coreset_...rb files are expected to sit into coresets directory):
module CoreSet; end
class CoreManager
class << self
def load_version(ver)
raise "Vesion #{ver} unknown" unless exists?(ver)
file = filename(ver)
code = File.read(file)
versioned_wrapper = Module.new do
class_eval code
end
CoreSet.const_set("V_#{ver.gsub('.', '_')}", versioned_wrapper)
end
private
def exists?(ver)
File.exists? filename(ver)
end
def filename(ver)
"coresets/coreset_#{ver.gsub('.', '_')}.rb"
end
end
end
CoreManager.load_version("1.0.0")
CoreManager.load_version("2.0.0")
p CoreSet::V_1_0_0::CoreA.who_am_i? # => "CoreSet::V_1_0_0::CoreA"
p CoreSet::V_1_0_0::CoreA.get_coreb # => CoreSet::V_1_0_0::CoreB
p CoreSet::V_2_0_0::CoreA.my_name # => "CoreSet::V_2_0_0::CoreA"
p CoreSet::V_2_0_0::CoreA.get_coreb # => CoreSet::V_2_0_0::CoreB
But, DON'T do this at home, please :) At least, I would think twice.
If all you need is to have all the versions loaded at once (you need namespaces exactly for this, right?) what stops you from defining them statically, like CoreSet::V1::Core<X> etc and use the idiomatic and safe ways to (auto)load them? :) Playing with dynamic nested constants definition (and, especially, their removing) is one of the easiest ways to shoot your own foot...
Ok I finally came to a solution that may help others or that can be discussed.
Getting the error uninitialized constant CoreA::CoreB (NameError) leads me to take the problem under a new angle. If I'm not able to access to CoreB module from CoreA (because the module nesting has been broken when redefining module constants into the CoreSet module) then why not referencing in each core module the other ones in the set ? And finaly it works without any dirty hack, I'm just creating pointers and the Ruby Core find it natively ;)
module CoreManager
def self.load_version(arg_version)
#Create a module set for the selected version
core_set_name = CoreSet + '_' + arg_version.gsub('.', '_')
core_set = eval("Module #{core_set_name}; end; #{core_set_name}"
#Load the requested code
toplevel_consts = Object.constants
require "coreset_#{arg_version}.rb"
core_modules = Object.constants - toplevel_consts
#Move the core modules to the set namespace
core_modules.collect! do |core_module|
core_module_sym = core_module.to_s.to_sym
core_set.const_set(core_module_sym, Object.send(:remove_const, core_module_sym))
eval("#{core_set}::#{core_module}")
end
#Create connexion between set cores to skirt broken module nesting
core_modules.each do |current_core|
core_modules.each do |other_core|
current_core.const_set(other_core.to_s.to_sym, other_core) unless current_core == other_core
end
end
#Return the created core set
core_set
end
end
Given I have defined the following modules in my features/support directory
apiworld.rb
module Api
class User
...
end
...
end
and also
webworld.rb
module Web
class User
...
end
...
end
in my env.rb file I have
env.rb
require File.expand_path(File.dirname(__FILE__)+'/webworld')
require File.expand_path(File.dirname(__FILE__)+'/apiworld')
if ENV['USE_API'] == 1
World(Api)
else
World(Web)
end
So if I try to use this construct in a step definition like
Given /^a user is created$/ do
#user = User.new
end
And run cucumber, my ruby interpreter will give me the this output
uninitialized constant User (NameError)
./features/step_definitions/user_steps.rb:17: [...]
How to make this work? Is there a way or am I thinking i the wrong direction. I am pretty new to ruby - so I don't really know what it can do and what it can not do.
You can't use World for this. World is for mixing methods into the self object in each stepdef.
Instead of this:
if ENV['USE_API'] == 1
World(Api)
else
World(Web)
end
Try this:
User = ENV['USE_API'] == 1 ? Api::User : Web::User
So, I'm trying to build a quick console program for my development needs, akin to rails console (I'm using Sinatra + DataMapper + pry).
I run it and launch cat = Category.new(name: 'TestCat', type: :referential). It gives me the following error:
Error: Cannot open "/home/art-solopov/Projects/by-language/Ruby/billy-bones/=" for reading.
What could be the cause of the problem?
console:
#!/usr/bin/env ruby
$LOAD_PATH << 'lib'
require 'pry'
require 'config'
binding.pry
lib/config.rb:
# Configuration files and app-wide requires go here
require 'sinatra'
require 'data_mapper'
require 'model/bill'
require 'model/category'
configure :production do
DataMapper::Logger.new('db-log', :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones')
DataMapper.finalize
end
configure :development do
DataMapper::Logger.new($stderr, :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones-dev')
DataMapper.finalize
DataMapper.auto_upgrade!
end
configure :test do
require 'dm_migrations'
DataMapper::Logger.new($stderr, :debug)
DataMapper.setup(:default,
'postgres://billy-bones:billy#localhost/billy-bones-test')
DataMapper.finalize
DataMapper.auto_migrate!
end
lib/model/category.rb:
require 'data_mapper'
class Category
include DataMapper::Resource
property :id, Serial
property :name, String
property :type, Enum[:referential, :predefined, :computable]
has n, :bills
# has n, :tariffs TODO uncomment when tariff ready
def create_bill(params)
# A bill factory for current category type
case type
when :referential
ReferentialBill.new params
when :predefined
PredefinedBill.new params
when :computable
ComputableBill.new params
end
end
end
If I substitute pry with irb in the console script, it goes fine.
Thank you very much!
P. S.
Okay, yesterday I tried this script again, and it worked perfectly. I didn't change anything. I'm not sure whether I should remove the question now or not.
P. P. S.
Or actually not... Today I've encountered it again. Still completely oblivious to what could cause it.
** SOLVED **
DAMN YOU PRY!
Okay, so here's the difference.
When I tested it the second time, I actually entered a = Category.new(name: 'TestCat', type: :referential) and it worked. Looks like pry just thinks cat is a Unix command, not a valid variable name.
Not answer to the pry question I just generally hate case statements in ruby.
Why not change:
def create_bill(params)
# A bill factory for current category type
case type
when :referential
ReferentialBill.new params
when :predefined
PredefinedBill.new params
when :computable
ComputableBill.new params
end
end
to:
def create_bill(params)
# A bill factory for current category type
self.send("new_#{type}_bill",params)
end
def new_referential_bill(params)
ReferentialBill.new params
end
def new_predefined_bill(params)
PredefinedBill.new params
end
def new_computable_bill(params)
ComputableBill.new params
end
You could make this more dynamic but I think that would take away from readability in this case but if you'd like in rails this should do the trick
def create_bill(params)
if [:referential, :predefined, :computable].include?(type)
"#{type}_bill".classify.constantize.new(params)
else
#Some Kind of Handling for non Defined Bill Types
end
end
Or this will work inside or outside rails
def create_bill(params)
if [:referential, :predefined, :computable].include?(type)
Object.const_get("#{type.to_s.capitalize}Bill").new(params)
else
#Some Kind of Handling for non Defined Bill Types
end
end
I'm trying to use the google_search ruby library (code follows) but it complains that 'cattr_accessor is an undefined method' - any ideas why this might be or how I could fix it?
require 'rubygems'
require 'google_search'
GoogleSearch.web :q => "pink floyd"
cattr_accessor seems to be a Rails extension that acts like attr_accessor, but is accessible on both the class and its instances.
If you want to copy the source of the cattr_accessor method, check out this documentation:
# File vendor/rails/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb, line 46
def cattr_accessor(*syms)
cattr_reader(*syms)
cattr_writer(*syms)
end
# File vendor/rails/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb, line 4
def cattr_reader(*syms)
syms.flatten.each do |sym|
next if sym.is_a?(Hash)
class_eval("unless defined? ##\#{sym}\n##\#{sym} = nil\nend\n\ndef self.\#{sym}\n##\#{sym}\nend\n\ndef \#{sym}\n##\#{sym}\nend\n", __FILE__, __LINE__)
end
end
# File vendor/rails/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb, line 24
def cattr_writer(*syms)
options = syms.extract_options!
syms.flatten.each do |sym|
class_eval("unless defined? ##\#{sym}\n##\#{sym} = nil\nend\n\ndef self.\#{sym}=(obj)\n##\#{sym} = obj\nend\n\n\#{\"\ndef \#{sym}=(obj)\n##\#{sym} = obj\nend\n\" unless options[:instance_writer] == false }\n", __FILE__, __LINE__)
end
end
You can get this functionality by including the Ruby Facets gem. Reference the source here:
https://github.com/rubyworks/facets/blob/master/lib/core/facets/cattr.rb
You generally don't need to require all code from the gem. You can selectively require what you want. There are quite a few useful extensions in the gem though.
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.