1 files changed, 32 insertions, 0 deletions
diff --git a/spec/ruby/core/hash/key_spec.rb b/spec/ruby/core/hash/key_spec.rb
new file mode 100644
index 0000000000..c2d7049aed
--- /dev/null
+++ b/spec/ruby/core/hash/key_spec.rb
@@ -0,0 +1,32 @@
+require_relative '../../spec_helper'
+
+describe "Hash#key?" do
+  it "is an alias of Hash#include?" do
+    Hash.instance_method(:key?).should == Hash.instance_method(:include?)
+  end
+end
+
+describe "Hash#key" do
+  it "returns the corresponding key for value" do
+    { 2 => 'a', 1 => 'b' }.key('b').should == 1
+  end
+
+  it "returns nil if the value is not found" do
+    { a: -1, b: 3.14, c: 2.718 }.key(1).should == nil
+  end
+
+  it "doesn't return default value if the value is not found" do
+    Hash.new(5).key(5).should == nil
+  end
+
+  it "compares values using ==" do
+    { 1 => 0 }.key(0.0).should == 1
+    { 1 => 0.0 }.key(0).should == 1
+
+    needle = mock('needle')
+    inhash = mock('inhash')
+    inhash.should_receive(:==).with(needle).and_return(true)
+
+    { 1 => inhash }.key(needle).should == 1
+  end
+end