Porting WebKit 114900 to blink: checkLayout() should error out if no data-expected* attributes were…

LayoutTests/resources/check-layout.js

 if (window.testRunner)
     testRunner.dumpAsText();
 
 (function() {
 
 function insertAfter(nodeToAdd, referenceNode)
 {
     if (referenceNode == document.body) {
         document.body.appendChild(nodeToAdd);
         return;
     }
 
     if (referenceNode.nextSibling)
         referenceNode.parentNode.insertBefore(nodeToAdd, referenceNode.nextSibling);
     else
         referenceNode.parentNode.appendChild(nodeToAdd);
 }
 
 function checkSubtreeExpectedValues(parent, failures)
 {
-    checkExpectedValues(parent, failures);
+    var checkedLayout = checkExpectedValues(parent, failures);
     Array.prototype.forEach.call(parent.childNodes, function(node) {
-        checkSubtreeExpectedValues(node, failures);
+        checkedLayout |= checkSubtreeExpectedValues(node, failures);
     });
+    return checkedLayout;
+}
+
+function checkAttribute(output, node, attribute)
+{
+    var result = node.getAttribute && node.getAttribute(attribute);
+    output.checked |= !!result;
+    return result;
 }
 
 function checkExpectedValues(node, failures)
 {
-    var expectedWidth = node.getAttribute && node.getAttribute("data-expected-width");
+    var output = { checked: false };
+    var expectedWidth = checkAttribute(output, node, "data-expected-width");
     if (expectedWidth) {
         if (node.offsetWidth != parseInt(expectedWidth))
             failures.push("Expected " + expectedWidth + " for width, but got " + node.offsetWidth + ". ");
     }
 
-    var expectedHeight = node.getAttribute && node.getAttribute("data-expected-height");
+    var expectedHeight = checkAttribute(output, node, "data-expected-height");
     if (expectedHeight) {
         if (node.offsetHeight != parseInt(expectedHeight))
             failures.push("Expected " + expectedHeight + " for height, but got " + node.offsetHeight + ". ");
     }
 
-    var expectedOffset = node.getAttribute && node.getAttribute("data-offset-x");
+    var expectedOffset = checkAttribute(output, node, "data-offset-x");
     if (expectedOffset) {
         if (node.offsetLeft != parseInt(expectedOffset))
             failures.push("Expected " + expectedOffset + " for offsetLeft, but got " + node.offsetLeft + ". ");
     }
 
-    var expectedOffset = node.getAttribute && node.getAttribute("data-offset-y");
+    var expectedOffset = checkAttribute(output, node, "data-offset-y");
     if (expectedOffset) {
         if (node.offsetTop != parseInt(expectedOffset))
             failures.push("Expected " + expectedOffset + " for offsetTop, but got " + node.offsetTop + ". ");
     }
 
-    var expectedWidth = node.getAttribute && node.getAttribute("data-expected-client-width");
+    var expectedWidth = checkAttribute(output, node, "data-expected-client-width");
     if (expectedWidth) {
         if (node.clientWidth != parseInt(expectedWidth))
             failures.push("Expected " + expectedWidth + " for clientWidth, but got " + node.clientWidth + ". ");
     }
 
-    var expectedHeight = node.getAttribute && node.getAttribute("data-expected-client-height");
+    var expectedHeight = checkAttribute(output, node, "data-expected-client-height");
     if (expectedHeight) {
         if (node.clientHeight != parseInt(expectedHeight))
             failures.push("Expected " + expectedHeight + " for clientHeight, but got " + node.clientHeight + ". ");
     }
 
-    var expectedWidth = node.getAttribute && node.getAttribute("data-expected-scroll-width");
+    var expectedWidth = checkAttribute(output, node, "data-expected-scroll-width");
     if (expectedWidth) {
         if (node.scrollWidth != parseInt(expectedWidth))
             failures.push("Expected " + expectedWidth + " for scrollWidth, but got " + node.scrollWidth + ". ");
     }
 
-    var expectedHeight = node.getAttribute && node.getAttribute("data-expected-scroll-height");
+    var expectedHeight = checkAttribute(output, node, "data-expected-scroll-height");
     if (expectedHeight) {
         if (node.scrollHeight != parseInt(expectedHeight))
             failures.push("Expected " + expectedHeight + " for scrollHeight, but got " + node.scrollHeight + ". ");
     }
 
-    var expectedOffset = node.getAttribute && node.getAttribute("data-total-x");
+    var expectedOffset = checkAttribute(output, node, "data-total-x");
     if (expectedOffset) {
         var totalLeft = node.clientLeft + node.offsetLeft;
         if (totalLeft != parseInt(expectedOffset))
             failures.push("Expected " + expectedOffset + " for clientLeft+offsetLeft, but got " + totalLeft + ", clientLeft: " + node.clientLeft + ", offsetLeft: " + node.offsetLeft + ". ");
     }
 
-    var expectedOffset = node.getAttribute && node.getAttribute("data-total-y");
+    var expectedOffset = checkAttribute(output, node, "data-total-y");
     if (expectedOffset) {
         var totalTop = node.clientTop + node.offsetTop;
         if (totalTop != parseInt(expectedOffset))
             failures.push("Expected " + expectedOffset + " for clientTop+offsetTop, but got " + totalTop + ", clientTop: " + node.clientTop + ", + offsetTop: " + node.offsetTop + ". ");
     }
 
-    var expectedDisplay = node.getAttribute && node.getAttribute("data-expected-display");
+    var expectedDisplay = checkAttribute(output, node, "data-expected-display");
     if (expectedDisplay) {
         var actualDisplay = getComputedStyle(node).display;
         if (actualDisplay != expectedDisplay)
             failures.push("Expected " + expectedDisplay + " for display, but got " + actualDisplay + ". ");
     }
 
-    var expectedPaddingTop = node.getAttribute && node.getAttribute("data-expected-padding-top");
+    var expectedPaddingTop = checkAttribute(output, node, "data-expected-padding-top");
     if (expectedPaddingTop) {
         var actualPaddingTop = getComputedStyle(node).paddingTop;
         // Trim the unit "px" from the output.
         actualPaddingTop = actualPaddingTop.substring(0, actualPaddingTop.length - 2);
         if (actualPaddingTop != expectedPaddingTop)
             failures.push("Expected " + expectedPaddingTop + " for padding-top, but got " + actualPaddingTop + ". ");
     }
 
-    var expectedPaddingBottom = node.getAttribute && node.getAttribute("data-expected-padding-bottom");
+    var expectedPaddingBottom = checkAttribute(output, node, "data-expected-padding-bottom");
     if (expectedPaddingBottom) {
         var actualPaddingBottom = getComputedStyle(node).paddingBottom;
         // Trim the unit "px" from the output.
         actualPaddingBottom = actualPaddingBottom.substring(0, actualPaddingBottom.length - 2);
         if (actualPaddingBottom != expectedPaddingBottom)
             failures.push("Expected " + expectedPaddingBottom + " for padding-bottom, but got " + actualPaddingBottom + ". ");
     }
 
-    var expectedPaddingLeft = node.getAttribute && node.getAttribute("data-expected-padding-left");
+    var expectedPaddingLeft = checkAttribute(output, node, "data-expected-padding-left");
     if (expectedPaddingLeft) {
         var actualPaddingLeft = getComputedStyle(node).paddingLeft;
         // Trim the unit "px" from the output.
         actualPaddingLeft = actualPaddingLeft.substring(0, actualPaddingLeft.length - 2);
         if (actualPaddingLeft != expectedPaddingLeft)
             failures.push("Expected " + expectedPaddingLeft + " for padding-left, but got " + actualPaddingLeft + ". ");
     }
 
-    var expectedPaddingRight = node.getAttribute && node.getAttribute("data-expected-padding-right");
+    var expectedPaddingRight = checkAttribute(output, node, "data-expected-padding-right");
     if (expectedPaddingRight) {
         var actualPaddingRight = getComputedStyle(node).paddingRight;
         // Trim the unit "px" from the output.
         actualPaddingRight = actualPaddingRight.substring(0, actualPaddingRight.length - 2);
         if (actualPaddingRight != expectedPaddingRight)
             failures.push("Expected " + expectedPaddingRight + " for padding-right, but got " + actualPaddingRight + ". ");
     }
 
-    var expectedMarginTop = node.getAttribute && node.getAttribute("data-expected-margin-top");
+    var expectedMarginTop = checkAttribute(output, node, "data-expected-margin-top");
     if (expectedMarginTop) {
         var actualMarginTop = getComputedStyle(node).marginTop;
         // Trim the unit "px" from the output.
         actualMarginTop = actualMarginTop.substring(0, actualMarginTop.length - 2);
         if (actualMarginTop != expectedMarginTop)
             failures.push("Expected " + expectedMarginTop + " for margin-top, but got " + actualMarginTop + ". ");
     }
 
-    var expectedMarginBottom = node.getAttribute && node.getAttribute("data-expected-margin-bottom");
+    var expectedMarginBottom = checkAttribute(output, node, "data-expected-margin-bottom");
     if (expectedMarginBottom) {
         var actualMarginBottom = getComputedStyle(node).marginBottom;
         // Trim the unit "px" from the output.
         actualMarginBottom = actualMarginBottom.substring(0, actualMarginBottom.length - 2);
         if (actualMarginBottom != expectedMarginBottom)
             failures.push("Expected " + expectedMarginBottom + " for margin-bottom, but got " + actualMarginBottom + ". ");
     }
 
-    var expectedMarginLeft = node.getAttribute && node.getAttribute("data-expected-margin-left");
+    var expectedMarginLeft = checkAttribute(output, node, "data-expected-margin-left");
     if (expectedMarginLeft) {
         var actualMarginLeft = getComputedStyle(node).marginLeft;
         // Trim the unit "px" from the output.
         actualMarginLeft = actualMarginLeft.substring(0, actualMarginLeft.length - 2);
         if (actualMarginLeft != expectedMarginLeft)
             failures.push("Expected " + expectedMarginLeft + " for margin-left, but got " + actualMarginLeft + ". ");
     }
 
-    var expectedMarginRight = node.getAttribute && node.getAttribute("data-expected-margin-right");
+    var expectedMarginRight = checkAttribute(output, node, "data-expected-margin-right");
     if (expectedMarginRight) {
         var actualMarginRight = getComputedStyle(node).marginRight;
         // Trim the unit "px" from the output.
         actualMarginRight = actualMarginRight.substring(0, actualMarginRight.length - 2);
         if (actualMarginRight != expectedMarginRight)
             failures.push("Expected " + expectedMarginRight + " for margin-right, but got " + actualMarginRight + ". ");
     }
+
+    return output.checked;
 }
 
 window.checkLayout = function(selectorList)
 {
     if (!selectorList) {
         console.error("You must provide a CSS selector of nodes to check.");
         return;
     }
     var nodes = document.querySelectorAll(selectorList);
     nodes = Array.prototype.slice.call(nodes);
     nodes.reverse();
+    var checkedLayout = false;
     Array.prototype.forEach.call(nodes, function(node) {
         var failures = [];
-        checkExpectedValues(node.parentNode, failures);
-        checkSubtreeExpectedValues(node, failures);
+        checkedLayout |= checkExpectedValues(node.parentNode, failures);
+        checkedLayout |= checkSubtreeExpectedValues(node, failures);
 
         var container = node.parentNode.className == 'container' ? node.parentNode : node;
 
         var pre = document.createElement('pre');
         if (failures.length)
             pre.className = 'FAIL';
         pre.appendChild(document.createTextNode(failures.length ? "FAIL:\n" + failures.join('\n') + '\n\n' + container.outerHTML : "PASS"));
         insertAfter(pre, container);
     });
+
+    if (!checkedLayout) {
+        document.body.innerHTML = "FAIL: No valid data-* attributes found in selector list : " + selectorList;
+        return;
+    }
+
     var pre = document.querySelector('.FAIL');
     if (pre)
         setTimeout(function() { pre.previousSibling.scrollIntoView(); }, 0);
 }
 
 })();