Bug 1357583: Test. r?heycam
MozReview-Commit-ID: BbMf3wcS6Pj
--- a/layout/style/test/mochitest.ini
+++ b/layout/style/test/mochitest.ini
@@ -268,16 +268,18 @@ skip-if = toolkit == 'android' #bug 7752
[test_shorthand_property_getters.html]
[test_specified_value_serialization.html]
[test_style_attr_listener.html]
[test_style_attribute_quirks.html]
[test_style_attribute_standards.html]
[test_style_struct_copy_constructors.html]
[test_stylesheet_clone_font_face.html]
skip-if = stylo # bug 1367523
+[test_stylesheet_additions.html]
+skip-if = !stylo
[test_supports_rules.html]
[test_system_font_serialization.html]
[test_text_decoration_shorthands.html]
[test_transitions_and_reframes.html]
[test_transitions_and_restyles.html]
[test_transitions_and_zoom.html]
[test_transitions_cancel_near_end.html]
[test_transitions_computed_values.html]
new file mode 100644
--- /dev/null
+++ b/layout/style/test/test_stylesheet_additions.html
@@ -0,0 +1,55 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>
+ Test for bug 1273303: Stylesheet additions and removals known to not
+ affect the document don't trigger restyles
+</title>
+<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<script src="/tests/SimpleTest/SimpleTest.js"></script>
+<div class="classScope">
+ <div></div>
+</div>
+<div id="idScope">
+ <div></div>
+</div>
+<!--
+ We do it this way, using `disabled`, because appending stylesheets to the
+ document marks a restyle as needed, so we can't accurately measure whether
+ we've restyled or not.
+-->
+<style id="target" disabled></style>
+<script>
+SimpleTest.waitForExplicitFinish();
+const utils = SpecialPowers.getDOMWindowUtils(window);
+const TESTS = [
+ { selector: ".nonexistentClassScope", restyle: false },
+ { selector: ".nonexistentClassScope + div", restyle: true },
+ { selector: ".nonexistentClassScope div + div", restyle: false },
+ { selector: ".classScope", restyle: true },
+ { selector: ".classScope div", restyle: true },
+ { selector: "#idScope", restyle: true },
+ { selector: "#nonexistentIdScope", restyle: false },
+ { selector: "#nonexistentIdScope div + bar", restyle: false },
+];
+
+for (const test of TESTS) {
+ // TODO(emilio): We don't as of right now, but we could also scan the
+ // stylesheet when removed if needed and test this too.
+ target.innerHTML = test.selector + " { color: green; }";
+ target.disabled = true;
+ document.body.offsetWidth;
+ const prevGeneration = utils.restyleGeneration;
+ target.disabled = false; // Make the stylesheet effective.
+ let element = document.querySelector(test.selector);
+ if (element) {
+ is(test.restyle, true, "How could we not expect a restyle?");
+ is(getComputedStyle(element).color, "rgb(0, 128, 0)",
+ "Element style should've changed appropriately");
+ }
+ document.body.offsetWidth;
+ is(test.restyle, utils.restyleGeneration != prevGeneration,
+ `Stylesheet addition with ${test.selector} should ${test.restyle ? "have" : "not have"} caused a restyle`);
+}
+
+SimpleTest.finish();
+</script>