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-rw-r--r--spec/ruby/core/enumerator/peek_spec.rb36
1 files changed, 36 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/peek_spec.rb b/spec/ruby/core/enumerator/peek_spec.rb
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+++ b/spec/ruby/core/enumerator/peek_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "Enumerator#peek" do
+ before :each do
+ @e = (1..5).to_a.to_enum
+ end
+
+ it "returns the next element in self" do
+ @e.peek.should == 1
+ end
+
+ it "does not advance the position of the current element" do
+ @e.next.should == 1
+ @e.peek.should == 2
+ @e.next.should == 2
+ end
+
+ it "can be called repeatedly without advancing the position of the current element" do
+ @e.peek
+ @e.peek
+ @e.peek.should == 1
+ @e.next.should == 1
+ end
+
+ it "works in concert with #rewind" do
+ @e.next
+ @e.next
+ @e.rewind
+ @e.peek.should == 1
+ end
+
+ it "raises StopIteration if called on a finished enumerator" do
+ 5.times { @e.next }
+ lambda { @e.peek }.should raise_error(StopIteration)
+ end
+end