1 files changed, 35 insertions, 0 deletions
diff --git a/spec/ruby/core/process/clock_gettime_spec.rb b/spec/ruby/core/process/clock_gettime_spec.rb
new file mode 100644
index 0000000000..165f0db730
--- /dev/null
+++ b/spec/ruby/core/process/clock_gettime_spec.rb
@@ -0,0 +1,35 @@
+require_relative '../../spec_helper'
+
+describe "Process.clock_gettime" do
+  describe 'time units' do
+    it 'handles a fixed set of time units' do
+      [:nanosecond, :microsecond, :millisecond, :second].each do |unit|
+        Process.clock_gettime(Process::CLOCK_MONOTONIC, unit).should be_kind_of(Integer)
+      end
+
+      [:float_microsecond, :float_millisecond, :float_second].each do |unit|
+        Process.clock_gettime(Process::CLOCK_MONOTONIC, unit).should be_an_instance_of(Float)
+      end
+    end
+
+    it 'raises an ArgumentError for an invalid time unit' do
+      lambda { Process.clock_gettime(Process::CLOCK_MONOTONIC, :bad) }.should raise_error(ArgumentError)
+    end
+
+    it 'defaults to :float_second' do
+      t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_second)
+
+      t1.should be_an_instance_of(Float)
+      t2.should be_close(t1, 2.0)  # 2.0 is chosen arbitrarily to allow for time skew without admitting failure cases, which would be off by an order of magnitude.
+    end
+
+    it 'uses the default time unit (:float_second) when passed nil' do
+      t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC, nil)
+      t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC, :float_second)
+
+      t1.should be_an_instance_of(Float)
+      t2.should be_close(t1, 2.0) # 2.0 is chosen arbitrarily to allow for time skew without admitting failure cases, which would be off by an order of magnitude.
+    end
+  end
+end