1 files changed, 33 insertions, 0 deletions
diff --git a/spec/ruby/core/integer/sqrt_spec.rb b/spec/ruby/core/integer/sqrt_spec.rb
new file mode 100644
index 0000000000..b7d9ef441b
--- /dev/null
+++ b/spec/ruby/core/integer/sqrt_spec.rb
@@ -0,0 +1,33 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+ruby_version_is "2.5" do
+  describe "Integer.sqrt" do
+    it "returns an integer" do
+      Integer.sqrt(10).should be_kind_of(Integer)
+    end
+
+    it "returns the integer square root of the argument" do
+      Integer.sqrt(0).should == 0
+      Integer.sqrt(1).should == 1
+      Integer.sqrt(24).should == 4
+      Integer.sqrt(25).should == 5
+      Integer.sqrt(10**400).should == 10**200
+    end
+
+    it "raises a Math::DomainError if the argument is negative" do
+      lambda { Integer.sqrt(-4) }.should raise_error(Math::DomainError)
+    end
+
+    it "accepts any argument that can be coerced to Integer" do
+      Integer.sqrt(10.0).should == 3
+    end
+
+    it "converts the argument with #to_int" do
+      Integer.sqrt(mock_int(10)).should == 3
+    end
+
+    it "raises a TypeError if the argument cannot be coerced to Integer" do
+      lambda { Integer.sqrt("test") }.should raise_error(TypeError)
+    end
+  end
+end