Merge pull request #28 from mstriemer/fix-triple-shift-1019729

Fix the >>>= operator (bug 1019729)

appvalidator/testcases/javascript/nodedefinitions.py

@@ -1,3 +1,4 @@
+import ctypes
 import types
 
 from appvalidator.constants import MAX_STR_SIZE
@@ -354,7 +355,8 @@ ASSIGNMENT_OPERATORS = {
     "%=": lambda l, r, gl, gr: 0 if gr == 0 else (gl % gr),
     "<<=": lambda l, r, gl, gr: int(gl) << int(gr),
     ">>=": lambda l, r, gl, gr: int(gl) >> int(gr),
-    ">>>=": lambda l, r, gl, gr: float(abs(int(gl)) >> gr),
+    ">>>=": lambda l, r, gl, gr: float(
+        ctypes.c_uint(int(gl)).value >> int(gr)),
     "|=": lambda l, r, gl, gr: int(gl) | int(gr),
     "^=": lambda l, r, gl, gr: int(gl) ^ int(gr),
     "&=": lambda l, r, gl, gr: int(gl) & int(gr),

tests/js/js_helper.py

@@ -66,6 +66,8 @@ class TestCase(helper.TestCase):
         Run the standard set of JS engine tests on the script passed via
         `script`.
         """
+        print "Running", script
+
         if self.err is None:
             self.setup_err()
 
@@ -90,6 +92,7 @@ class TestCase(helper.TestCase):
         Assert that the value of a variable from the final script context
         contains the value specified.
         """
+        print "Testing {var} == {val}".format(var=name, val=value)
         val = self.get_var(name)
         if isinstance(val, float):
             val *= 100000

tests/js/test_math.py

@@ -170,3 +170,23 @@ class TestMathFuncs(TestCase):
         """)
 
         # We really don't care about the output here.
+
+    def test_bit_shifting(self):
+        """Test for bit shifting operators."""
+        self.setUp()
+        self.run_script("""
+            var x = 1;
+            x >>= 0;""")
+        self.assert_var_eq("x", 1)
+        self.run_script("""
+            var x = 1;
+            x >>= 1""")
+        self.assert_var_eq("x", 0)
+        self.run_script("""
+            var x = -1;
+            x >>= 0;""")
+        self.assert_var_eq("x", -1)
+        self.run_script("""
+            var x = -1;
+            x >>>= 0.2""")
+        self.assert_var_eq("x", 0xFFFFFFFF)