1 files changed, 35 insertions, 1 deletions
diff --git a/spec/ruby/core/exception/case_compare_spec.rb b/spec/ruby/core/exception/case_compare_spec.rb
index a4c9eaa6bf..87b9dee3ca 100644
--- a/spec/ruby/core/exception/case_compare_spec.rb
+++ b/spec/ruby/core/exception/case_compare_spec.rb
@@ -1,5 +1,39 @@
 require_relative '../../spec_helper'
 
 describe "SystemCallError.===" do
-  it "needs to be reviewed for spec completeness"
+  before :all do
+    @example_errno_class = Errno::EINVAL
+    @example_errno = @example_errno_class::Errno
+  end
+
+  it "returns true for an instance of the same class" do
+    Errno::EINVAL.should === Errno::EINVAL.new
+  end
+
+  it "returns true if errnos same" do
+    e = SystemCallError.new('foo', @example_errno)
+    @example_errno_class.===(e).should == true
+  end
+
+  it "returns false if errnos different" do
+    e = SystemCallError.new('foo', @example_errno + 1)
+    @example_errno_class.===(e).should == false
+  end
+
+  it "returns false if arg is not kind of SystemCallError" do
+    e = Object.new
+    @example_errno_class.===(e).should == false
+  end
+
+  it "returns true if receiver is generic and arg is kind of SystemCallError" do
+    unknown_error_number = Errno.constants.size
+    e = SystemCallError.new('foo', @example_errno)
+    SystemCallError.===(e).should == true
+  end
+
+  it "returns false if receiver is generic and arg is not kind of SystemCallError" do
+    unknown_error_number = Errno.constants.size
+    e = Object.new
+    SystemCallError.===(e).should == false
+  end
 end