1 files changed, 49 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_animation_setPlaybackRate.js b/devtools/server/tests/browser/browser_animation_setPlaybackRate.js
new file mode 100644
index 0000000000..b14751b114
--- /dev/null
+++ b/devtools/server/tests/browser/browser_animation_setPlaybackRate.js
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that a player's playbackRate can be changed, and that multiple players
+// can have their rates changed at the same time.
+
+add_task(async function () {
+  const { target, walker, animations } = await initAnimationsFrontForUrl(
+    MAIN_DOMAIN + "animation.html"
+  );
+
+  info("Retrieve an animated node");
+  let node = await walker.querySelector(walker.rootNode, ".simple-animation");
+
+  info("Retrieve the animation player for the node");
+  const [player] = await animations.getAnimationPlayersForNode(node);
+
+  info("Change the rate to 10");
+  await animations.setPlaybackRates([player], 10);
+
+  info("Query the state again");
+  let state = await player.getCurrentState();
+  is(state.playbackRate, 10, "The playbackRate was updated");
+
+  info("Change the rate back to 1");
+  await animations.setPlaybackRates([player], 1);
+
+  info("Query the state again");
+  state = await player.getCurrentState();
+  is(state.playbackRate, 1, "The playbackRate was changed back");
+
+  info("Retrieve several animation players and set their rates");
+  node = await walker.querySelector(walker.rootNode, "body");
+  const players = await animations.getAnimationPlayersForNode(node);
+
+  info("Change all animations in <body> to .5 rate");
+  await animations.setPlaybackRates(players, 0.5);
+
+  info("Query their states and check they are correct");
+  for (const animPlayer of players) {
+    const animPlayerState = await animPlayer.getCurrentState();
+    is(animPlayerState.playbackRate, 0.5, "The playbackRate was updated");
+  }
+
+  await target.destroy();
+  gBrowser.removeCurrentTab();
+});