1 files changed, 60 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/lazy/drop_while_spec.rb b/spec/ruby/core/enumerator/lazy/drop_while_spec.rb
new file mode 100644
index 0000000000..a08644a20c
--- /dev/null
+++ b/spec/ruby/core/enumerator/lazy/drop_while_spec.rb
@@ -0,0 +1,60 @@
+# -*- encoding: us-ascii -*-
+
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Enumerator::Lazy#drop_while" do
+  before :each do
+    @yieldsmixed = EnumeratorLazySpecs::YieldsMixed.new.to_enum.lazy
+    @eventsmixed = EnumeratorLazySpecs::EventsMixed.new.to_enum.lazy
+    ScratchPad.record []
+  end
+
+  after :each do
+    ScratchPad.clear
+  end
+
+  it "returns a new instance of Enumerator::Lazy" do
+    ret = @yieldsmixed.drop_while {}
+    ret.should be_an_instance_of(Enumerator::Lazy)
+    ret.should_not equal(@yieldsmixed)
+  end
+
+  it "sets #size to nil" do
+    Enumerator::Lazy.new(Object.new, 100) {}.drop_while { |v| v }.size.should == nil
+  end
+
+  describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
+    it "stops after specified times" do
+      (0..Float::INFINITY).lazy.drop_while { |n| n < 5 }.first(2).should == [5, 6]
+
+      @eventsmixed.drop_while { false }.first(1)
+      ScratchPad.recorded.should == [:before_yield]
+    end
+  end
+
+  it "calls the block with initial values when yield with multiple arguments" do
+    yields = []
+    @yieldsmixed.drop_while { |v| yields << v; true }.force
+    yields.should == EnumeratorLazySpecs::YieldsMixed.initial_yields
+  end
+
+  it "raises an ArgumentError when not given a block" do
+    lambda { @yieldsmixed.drop_while }.should raise_error(ArgumentError)
+  end
+
+  describe "on a nested Lazy" do
+    it "sets #size to nil" do
+      Enumerator::Lazy.new(Object.new, 100) {}.take(20).drop_while { |v| v }.size.should == nil
+    end
+
+    describe "when the returned lazy enumerator is evaluated by Enumerable#first" do
+      it "stops after specified times" do
+        (0..Float::INFINITY).lazy.drop_while { |n| n < 5 }.drop_while { |n| n.odd? }.first(2).should == [6, 7]
+
+        @eventsmixed.drop_while { false }.drop_while { false }.first(1)
+        ScratchPad.recorded.should == [:before_yield]
+      end
+    end
+  end
+end