layout/style/test/test_reframe_input.html

   1 <!doctype html>
   2 <meta charset="utf-8">
   3 <title>Test for bug 1658302: We don't reframe for placeholder attribute value changes.</title>
   4 <link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
   5 <script src="/tests/SimpleTest/SimpleTest.js"></script>
   6 <input id="input">
   7 <textarea id="textarea"></textarea>
   8 <script>
   9 SimpleTest.waitForExplicitFinish();
  10 const utils = SpecialPowers.DOMWindowUtils;
  11
  12 function expectReframe(shouldHaveReframed, callback) {
  13   document.documentElement.offsetTop;
  14   const previousConstructCount = utils.framesConstructed;
  15   const previousReflowCount = utils.framesReflowed;
  16
  17   callback();
  18
  19   document.documentElement.offsetTop;
  20   isnot(previousReflowCount, utils.framesReflowed, "We should have reflowed");
  21   (shouldHaveReframed ? isnot : is)(previousConstructCount,
  22                                     utils.framesConstructed,
  23     `We should ${shouldHaveReframed ? "" : "not"} have reframed`);
  24 }
  25
  26 for (const control of document.querySelectorAll("input, textarea")) {
  27   // Creating the placeholder attribute reframes right now.
  28   //
  29   // TODO: Could be avoided with some more work.
  30   expectReframe(true, () => {
  31     control.placeholder = "foo";
  32   });
  33
  34   // Incrementally changing it should not reframe, just reflow.
  35   expectReframe(false, () => {
  36     control.placeholder = "bar";
  37   });
  38
  39   // Removing the placeholder attribute reframes right now.
  40   //
  41   // TODO: Could maybe be avoided with some more work.
  42   expectReframe(true, () => {
  43     control.removeAttribute("placeholder");
  44   });
  45 }
  46
  47 SimpleTest.finish();
  48 </script>