1 files changed, 62 insertions, 0 deletions
diff --git a/devtools/client/webconsole/enhancers/actor-releaser.js b/devtools/client/webconsole/enhancers/actor-releaser.js
new file mode 100644
index 0000000000..30232c232a
--- /dev/null
+++ b/devtools/client/webconsole/enhancers/actor-releaser.js
@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {
+  MESSAGES_ADD,
+  MESSAGES_CLEAR,
+  PRIVATE_MESSAGES_CLEAR,
+  FRONTS_TO_RELEASE_CLEAR,
+} = require("resource://devtools/client/webconsole/constants.js");
+
+/**
+ * This enhancer is responsible for releasing actors on the backend.
+ * When messages with arguments are removed from the store we should also
+ * clean up the backend.
+ */
+function enableActorReleaser(webConsoleUI) {
+  return next => (reducer, initialState, enhancer) => {
+    function releaseActorsEnhancer(state, action) {
+      state = reducer(state, action);
+
+      const { type } = action;
+      if (
+        webConsoleUI &&
+        [MESSAGES_ADD, MESSAGES_CLEAR, PRIVATE_MESSAGES_CLEAR].includes(type)
+      ) {
+        const promises = [];
+        state.messages.frontsToRelease.forEach(front => {
+          // We only release the front if it actually has a release method, if it isn't
+          // already destroyed, and if it's not in the sidebar (where we might still need it).
+          if (
+            front &&
+            typeof front.release === "function" &&
+            !front.isDestroyed() &&
+            (!state.ui.frontInSidebar ||
+              state.ui.frontInSidebar.actorID !== front.actorID)
+          ) {
+            promises.push(front.release());
+          }
+        });
+
+        // Emit an event we can listen to to make sure all the fronts were released.
+        Promise.all(promises).then(() =>
+          webConsoleUI.emitForTests("fronts-released")
+        );
+
+        // Reset `frontsToRelease` in message reducer.
+        state = reducer(state, {
+          type: FRONTS_TO_RELEASE_CLEAR,
+        });
+      }
+
+      return state;
+    }
+
+    return next(releaseActorsEnhancer, initialState, enhancer);
+  };
+}
+
+module.exports = enableActorReleaser;