Contents

covers 'facets/enumerable/find_yield'

test_case Enumerable do
  
  method :find_yield do

    test "a value" do
      r = [true].find_yield { |value| value }
      r.assert == true
    end

    test "detects correct value" do
      r = [1].find_yield { |value| value }
      r.assert == 1
    end

    test "returns value of block" do
      r = [1].find_yield { |v| v + 3 }
      r.assert == 4
    end

    test "detects first truthy value" do
      r = [false, false, 1].find_yield { |value| value }
      r.assert == 1
    end

    test "returns value when block is true" do
      r = [false].find_yield { |value| true }
      r.assert == true
    end

    test "returns early when block is true" do
      v1 = lambda { :something }
      v2 = lambda { raise "This shouldn't be called" }
      r = [v1, v2].find_yield { |obj| obj.call }
      r.assert == :something
    end

    test "returns nil when block returns false for all elements" do
      r = [1,2,3,4].find_yield { |value| false }
      r.assert == nil
    end

    test "returns nil when no elements in collection" do
      r = [].find_yield { |v| }
      r.assert == nil
    end

    test "can have return value specified when block isnt true" do
      r = [1,2,3].find_yield(:a_value){ |value| false }
      r.assert == :a_value
    end

    test "documentation correct" do
      obj1, obj2 = Object.new, Object.new

      class << obj1
        def foo?
          false
        end

        def foo
          raise
        end
      end

      class << obj2
        def foo?
          true
        end

        def foo
          "a value"
        end
      end

      obj1.foo?.assert == false
      obj2.foo?.assert == true
      obj2.foo.assert == "a value"

      result = [obj1, obj2].find_yield { |obj| obj.foo if obj.foo? }
      result.assert == "a value"
    end

  end

  method :map_detect do

    test "old alias for #find_yield" do
      r = [true].map_detect{ |value| value }
      r.assert == true
    end

  end

end

Version data entries

5 entries across 5 versions & 2 rubygems

Version	Path
facets-glimmer-3.2.0	test/core/enumerable/test_find_yield.rb
facets-3.1.0	test/core/enumerable/test_find_yield.rb
facets-3.0.0	test/core/enumerable/test_find_yield.rb
facets-2.9.3	test/core/enumerable/test_find_yield.rb
facets-2.9.2	test/core/enumerable/test_find_yield.rb