Noissue - Allow identifying the element in case of error in test

test/browser/elemHideEmulation.js

Index: test/browser/elemHideEmulation.js
===================================================================
--- a/test/browser/elemHideEmulation.js
+++ b/test/browser/elemHideEmulation.js
@@ -50,26 +50,32 @@
 }
 
 function unexpectedError(error)
 {
   console.error(error);
   this.ok(false, "Unexpected error: " + error);
 }
 
-function expectHidden(test, element)
+function expectHidden(test, element, id)
 {
-  test.equal(window.getComputedStyle(element).display, "none",
-             "The element's display property should be set to 'none'");
+  let message = id ?

[kzar, 2018/03/21 18:11:59]

This seems kind of messy, also I guess the ID might be zero. How about something
like this? (Though to be honest its still kind of messy :/)

function expectHidden(test, element, id)
{
  let withId = "";
  if (typeof id != "undefined")
    withId = ` with ID '${id}'`;

  test.equal(
    window.getComputedStyle(element).display, "none",
    "The element" + withId + "'s display property should be set to none"
  );
}

[hub, 2018/03/21 19:05:04]

Done.

[hub, 2018/03/21 19:05:04]

Hence my original approach, since these are just test and not end-user visible
text.

[kzar, 2018/03/22 09:40:04]

Sorry I was talking nonsense here, the ID is a string not a number.

[kzar, 2018/03/22 09:40:04]

Yea fair enough.

+      `The element with ID '${id}' display property should be set to 'none'` :
+      "The element's display property should be set to 'none'";
+  test.equal(
+    window.getComputedStyle(element).display, "none", message);
 }
 
-function expectVisible(test, element)
+function expectVisible(test, element, id)
 {
-  test.notEqual(window.getComputedStyle(element).display, "none",
-                "The element's display property should not be set to 'none'");
+  let message = id ?
+      `The element with ID '${id}' display property should not be set to 'none'` :
+      "The element's display property should not be set to 'none'";
+  test.notEqual(
+    window.getComputedStyle(element).display, "none", message);
 }
 
 function findUniqueId()
 {
   let id = "elemHideEmulationTest-" + Math.floor(Math.random() * 10000);
   if (!testDocument.getElementById(id))
     return id;
   return findUniqueId();
@@ -355,19 +361,19 @@
 
 function compareExpectations(test, elems, expectations)
 {
   for (let elem in expectations)
   {
     if (elems[elem])
     {
       if (expectations[elem])
-        expectVisible(test, elems[elem]);
+        expectVisible(test, elems[elem], elem);
       else
-        expectHidden(test, elems[elem]);
+        expectHidden(test, elems[elem], elem);
     }
   }
 }
 
 function runTestPseudoClassHasSelectorWithHasAndWithSuffixSibling(test, selector, expectations)
 {
   testDocument.body.innerHTML = `<div id="parent">
       <div id="middle">