Import wpt@ed94c51f3dfaa5ff4c9c311add1a560408059c51

third_party/WebKit/LayoutTests/imported/wpt/common/stringifiers.js

+// Tests <http://heycam.github.io/webidl/#es-stringifier>.
+function test_stringifier_attribute(aObject, aAttribute, aIsUnforgeable) {
+  // Step 1.
+  test(function() {
+    [null, undefined].forEach(function(v) {
+      assert_throws(new TypeError(), function() {
+        aObject.toString.call(v);
+      });
+    });
+  });
+
+  // TODO Step 2: security check.
+
+  // Step 3.
+  test(function() {
+    assert_false("Window" in window && aObject instanceof window.Window);
+    [{}, window].forEach(function(v) {
+      assert_throws(new TypeError(), function() {
+        aObject.toString.call(v)
+      });
+    });
+  });
+
+  // Step 4-6.
+  var expected_value;
+  test(function() {
+    expected_value = aObject[aAttribute];
+    assert_equals(aObject[aAttribute], expected_value,
+                  "The attribute " + aAttribute + " should be pure.");
+  });
+
+  var test_error = { name: "test" };
+  test(function() {
+    if (!aIsUnforgeable) {
+      Object.defineProperty(aObject, aAttribute, {
+        configurable: true,
+        get: function() { throw test_error; }
+      });
+    }
+    assert_equals(aObject.toString(), expected_value);
+  });
+
+  test(function() {
+    if (!aIsUnforgeable) {
+      Object.defineProperty(aObject, aAttribute, {
+        configurable: true,
+        value: { toString: function() { throw test_error; } }
+      });
+    }
+    assert_equals(aObject.toString(), expected_value);
+  });
+}