1 files changed, 33 insertions, 0 deletions
diff --git a/spec/ruby/core/process/clock_getres_spec.rb b/spec/ruby/core/process/clock_getres_spec.rb
new file mode 100644
index 0000000000..85aa2b25f1
--- /dev/null
+++ b/spec/ruby/core/process/clock_getres_spec.rb
@@ -0,0 +1,33 @@
+require_relative '../../spec_helper'
+
+describe "Process.clock_getres" do
+  # These are documented
+
+  it "with :GETTIMEOFDAY_BASED_CLOCK_REALTIME reports 1 microsecond" do
+    Process.clock_getres(:GETTIMEOFDAY_BASED_CLOCK_REALTIME, :nanosecond).should == 1_000
+  end
+
+  it "with :TIME_BASED_CLOCK_REALTIME reports 1 second" do
+    Process.clock_getres(:TIME_BASED_CLOCK_REALTIME, :nanosecond).should == 1_000_000_000
+  end
+
+  platform_is_not :windows do
+    it "with :GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID reports 1 microsecond" do
+      Process.clock_getres(:GETRUSAGE_BASED_CLOCK_PROCESS_CPUTIME_ID, :nanosecond).should == 1_000
+    end
+  end
+
+  # These are observed
+
+  platform_is :linux, :darwin, :windows do
+    it "with Process::CLOCK_REALTIME reports at least 10 millisecond" do
+      Process.clock_getres(Process::CLOCK_REALTIME, :nanosecond).should <= 10_000_000
+    end
+  end
+
+  platform_is :linux, :darwin, :windows do
+    it "with Process::CLOCK_MONOTONIC reports at least 10 millisecond" do
+      Process.clock_getres(Process::CLOCK_MONOTONIC, :nanosecond).should <= 10_000_000
+    end
+  end
+end