<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" href="chrome://mochikit/content/tests/SimpleTest/test.css" />
<style>
  #grid {
    display: grid;
    width: 100px;
    height: 100px;
  }

  .cellOriginal {
    grid-column-end: span 2;
  }

  .cellChanged {
    grid-column-end: span 5;
  }
</style>
<script>
"use strict";

SimpleTest.waitForExplicitFinish();

function runTests() {
  const grid = document.getElementById("grid");
  const cell = document.getElementById("cell");

  const gridA = grid.getGridFragments()[0];

  // Check that grid fragments are equal across reflows.
  document.documentElement.offsetHeight; // Flush layout.
  const gridB = grid.getGridFragments()[0];
  is(gridB, gridA, "Grid fragments should be the same across reflows.");

  // Check that grid fragments are different when styles are different.
  cell.classList.replace("cellOriginal", "cellChanged");
  const gridC = grid.getGridFragments()[0];
  isnot(gridC, gridA, "Grids with different styles should have different fragments.");

  // Check that changing a grid to a matching style results in different fragments.
  cell.classList.replace("cellChanged", "cellOriginal");
  const gridD = grid.getGridFragments()[0];
  isnot(gridD, gridA, "Grids changed to the same styles should have different fragments.");

  SimpleTest.finish();
}
</script>
</head>
<body onLoad="runTests();">
<div id="grid">
  <div id="cell" class="cellOriginal"></div>
</div>
</body>
</html>
