File#utime: Don't check for usec resolution on Darwin

Author: andre-richter

spec/ruby/core/file/utime_spec.rb

@@ -22,28 +22,30 @@
     File.mtime(@file2).to_i.should be_close(@mtime.to_i, 2)
   end
 
-  it "sets and gets microseconds from Time arguments" do
-    File.utime(@atime, @mtime, @file1, @file2)
-    File.atime(@file1).usec.should equal(10)
-    File.mtime(@file1).usec.should equal(10)
-    File.atime(@file2).usec.should equal(10)
-    File.mtime(@file2).usec.should equal(10)
-  end
-
-  it "sets and gets microseconds from Float arguments" do
-    File.utime(0.0001, 0.0001, @file1, @file2)
-    File.atime(@file1).usec.should equal(100)
-    File.mtime(@file1).usec.should equal(100)
-    File.atime(@file2).usec.should equal(100)
-    File.mtime(@file2).usec.should equal(100)
-  end
-
-  it "sets and gets microseconds from Rational arguments" do
-    File.utime(Rational(1, 1000), Rational(1, 1000), @file1, @file2)
-    File.atime(@file1).usec.should equal(1000)
-    File.mtime(@file1).usec.should equal(1000)
-    File.atime(@file2).usec.should equal(1000)
-    File.mtime(@file2).usec.should equal(1000)
+  platform_is_not :darwin do
+    it "sets and gets microseconds from Time arguments" do
+      File.utime(@atime, @mtime, @file1, @file2)
+      File.atime(@file1).usec.should equal(10)
+      File.mtime(@file1).usec.should equal(10)
+      File.atime(@file2).usec.should equal(10)
+      File.mtime(@file2).usec.should equal(10)
+    end
+
+    it "sets and gets microseconds from Float arguments" do
+      File.utime(0.0001, 0.0001, @file1, @file2)
+      File.atime(@file1).usec.should equal(100)
+      File.mtime(@file1).usec.should equal(100)
+      File.atime(@file2).usec.should equal(100)
+      File.mtime(@file2).usec.should equal(100)
+    end
+
+    it "sets and gets microseconds from Rational arguments" do
+      File.utime(Rational(1, 1000), Rational(1, 1000), @file1, @file2)
+      File.atime(@file1).usec.should equal(1000)
+      File.mtime(@file1).usec.should equal(1000)
+      File.atime(@file2).usec.should equal(1000)
+      File.mtime(@file2).usec.should equal(1000)
+    end
   end
 
   it "uses the current times if two nil values are passed" do