ruby 中的 'where' 行为是什么？

Question

我正在尝试编写一个模块来通过我的所有测试。它看起来像是一个哈希数组。我想弄清楚 'where' 逻辑是什么？所以我可以尝试编写一个模块来通过所有测试。

测试：

require 'test/unit'

class WhereTest < Test::Unit::TestCase
def setup
 @boris   = {:name => 'Boris The Blade', :quote => "Heavy is good. Heavy is reliable. If it doesn't work you can always hit them.", :title => 'Snatch', :rank => 4}
 @charles = {:name => 'Charles De Mar', :quote => 'Go that way, really fast. If something gets in your way, turn.', :title => 'Better Off Dead', :rank => 3}
 @wolf    = {:name => 'The Wolf', :quote => 'I think fast, I talk fast and I need you guys to act fast if you wanna get out of this', :title => 'Pulp Fiction', :rank => 4}
 @glen    = {:name => 'Glengarry Glen Ross', :quote => "Put. That coffee. Down. Coffee is for closers only.",  :title => "Blake", :rank => 5}

 @fixtures = [@boris, @charles, @wolf, @glen]
end

def test_where_with_exact_match
  assert_equal [@wolf], @fixtures.where(:name => 'The Wolf')
end

def test_where_with_partial_match
  assert_equal [@charles, @glen], @fixtures.where(:title => /^B.*/)
end

def test_where_with_mutliple_exact_results
  assert_equal [@boris, @wolf], @fixtures.where(:rank => 4)
end

def test_with_with_multiple_criteria
  assert_equal [@wolf], @fixtures.where(:rank => 4, :quote => /get/)
end

def test_with_chain_calls
  assert_equal [@charles], @fixtures.where(:quote => /if/i).where(:rank => 3)
end

end

Answer 1

仔细看你的第一个测试：

@fixtures.where(:name => 'The Wolf')

@fixtures 对象属于 class Array，您正在对其调用名称为 where 的方法。因此，要使此测试通过，您必须在 Array 或其父 class 之一上定义一个名为 where 的方法。作为第一次尝试，您可以这样写：

class Array
  def where(options)
  end
end

我想这就是你要问的。编写上面的代码后，您应该从测试中得到不同的错误消息。您的工作是在 where 方法中编写代码以使您的所有测试都通过。

ruby 中的 'where' 行为是什么？

What is the 'where' behavior in ruby?

ruby

arrays

methods

hash