Alternative to a selective Mocha::ClassMethods#any_instance

foo_test.rb

require "test/unit"
require "rubygems"
require "mocha"

class Foo
  attr_reader :argument
  def initialize(argument)
    @argument = argument
  end
  def bar
    "bar"
  end
end

class FooTest < Test::Unit::TestCase
  def test_foo
    foo_one = Foo.new(1)
    foo_one.stubs(:bar).returns("one")

    foo_two = Foo.new(2)
    foo_two.stubs(:bar).returns("two")

    default_foo = Foo.new(nil)

    Foo.stubs(:new).returns(default_foo)
    Foo.stubs(:new).with(1).returns(foo_one)
    Foo.stubs(:new).with(2).returns(foo_two)

    assert_equal 1, Foo.new(1).argument
    assert_equal "one", Foo.new(1).bar

    assert_equal 2, Foo.new(2).argument
    assert_equal "two", Foo.new(2).bar

    assert_equal nil, Foo.new(3).argument
    assert_equal "bar", Foo.new(3).bar
  end
end


# $ ruby foo_test.rb
# Loaded suite foo_test
# Started
# .
# Finished in 0.001324 seconds.
#
# 1 tests, 6 assertions, 0 failures, 0 errors