1 files changed, 39 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_animation_reconstructState.js b/devtools/server/tests/browser/browser_animation_reconstructState.js
new file mode 100644
index 0000000000..a403e60265
--- /dev/null
+++ b/devtools/server/tests/browser/browser_animation_reconstructState.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that, even though the AnimationPlayerActor only sends the bits of its
+// state that change, the front reconstructs the whole state everytime.
+
+add_task(async function() {
+  const { target, walker, animations } = await initAnimationsFrontForUrl(
+    MAIN_DOMAIN + "animation.html"
+  );
+
+  await playerHasCompleteStateAtAllTimes(walker, animations);
+
+  await target.destroy();
+  gBrowser.removeCurrentTab();
+});
+
+async function playerHasCompleteStateAtAllTimes(walker, animations) {
+  const node = await walker.querySelector(walker.rootNode, ".simple-animation");
+  const [player] = await animations.getAnimationPlayersForNode(node);
+
+  // Get the list of state key names from the initialstate.
+  const keys = Object.keys(player.initialState);
+
+  // Get the state over and over again and check that the object returned
+  // contains all keys.
+  // Normally, only the currentTime will have changed in between 2 calls.
+  for (let i = 0; i < 10; i++) {
+    await player.refreshState();
+    keys.forEach(key => {
+      ok(
+        typeof player.state[key] !== "undefined",
+        "The state retrieved has key " + key
+      );
+    });
+  }
+}