1 files changed, 58 insertions, 0 deletions
diff --git a/spec/rubyspec/core/integer/lcm_spec.rb b/spec/rubyspec/core/integer/lcm_spec.rb
new file mode 100644
index 0000000000..ddf25d3853
--- /dev/null
+++ b/spec/rubyspec/core/integer/lcm_spec.rb
@@ -0,0 +1,58 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+describe "Integer#lcm" do
+  it "returns self if equal to the argument" do
+    1.lcm(1).should == 1
+    398.lcm(398).should == 398
+  end
+
+  it "returns an Integer" do
+    36.lcm(6).should be_kind_of(Integer)
+    4.lcm(20981).should be_kind_of(Integer)
+  end
+
+  it "returns the least common multiple of self and argument" do
+    200.lcm(2001).should == 400200
+    99.lcm(90).should == 990
+  end
+
+  it "returns a positive integer even if self is negative" do
+    -12.lcm(6).should == 12
+    -100.lcm(100).should == 100
+  end
+
+  it "returns a positive integer even if the argument is negative" do
+    12.lcm(-6).should == 12
+    100.lcm(-100).should == 100
+  end
+
+  it "returns a positive integer even if both self and argument are negative" do
+    -12.lcm(-6).should == 12
+    -100.lcm(-100).should == 100
+  end
+
+  it "accepts a Bignum argument" do
+    bignum = 9999**99
+    bignum.should be_kind_of(Bignum)
+    99.lcm(bignum).should == bignum
+  end
+
+  it "works if self is a Bignum" do
+    bignum = 9999**99
+    bignum.should be_kind_of(Bignum)
+    bignum.lcm(99).should == bignum
+  end
+
+  it "raises an ArgumentError if not given an argument" do
+    lambda { 12.lcm }.should raise_error(ArgumentError)
+  end
+
+  it "raises an ArgumentError if given more than one argument" do
+    lambda { 12.lcm(30, 20) }.should raise_error(ArgumentError)
+  end
+
+  it "raises a TypeError unless the argument is an Integer" do
+    lambda { 39.lcm(3.8)   }.should raise_error(TypeError)
+    lambda { 45872.lcm([]) }.should raise_error(TypeError)
+  end
+end