1 files changed, 45 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/css-grid/support/grid-child-utils.js b/testing/web-platform/tests/css/css-grid/support/grid-child-utils.js
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+++ b/testing/web-platform/tests/css/css-grid/support/grid-child-utils.js
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+// Any copyright is dedicated to the Public Domain.
+// https://creativecommons.org/publicdomain/zero/1.0/
+
+const gridChildHelperRow = "row";
+const gridChildHelperCol = "col";
+
+// Helper for building testcases for grid-template-* with a child div in
+// multiple positions. Prop is expected to be one of gridChildHelperRow or
+// gridChildHelperCol, to select testing grid rows or grid columns,
+// respectively.
+// The child div is found by the id of 'child'.
+function GridChildHelper(prop, style){
+  this.child = document.getElementById("child");
+  this.style = style;
+  this.prop = prop;
+}
+
+// Runs a test for computed values on the property the helper object was
+// constructed with. The childStyle is used for choosing the grid row/column
+// of the child div.
+// expected is passed as-is to the computed value test.
+// The child style is appended to the test name in such a way that different
+// tests for the same parent style but different child style values will have
+// different test names.
+GridChildHelper.prototype.runTest = function(childStyle, expected) {
+  'use strict';
+  const childProps = {
+    [gridChildHelperCol]:"gridColumn",
+    [gridChildHelperRow]:"gridRow"
+  };
+  const childProp = childProps[this.prop];
+
+  const parentProps = {
+    [gridChildHelperCol]:"grid-template-columns",
+    [gridChildHelperRow]:"grid-template-rows"
+  };
+  const parentProp = parentProps[this.prop];
+
+  const oldChildStyle = this.child[childProp];
+  this.child.style[childProp] = childStyle;
+
+  test_computed_value(parentProp, this.style, expected, childProp + " = " + childStyle);
+
+  this.child[childProp] = oldChildStyle;
+}