1 files changed, 71 insertions, 0 deletions
diff --git a/devtools/client/webconsole/middleware/history-persistence.js b/devtools/client/webconsole/middleware/history-persistence.js
new file mode 100644
index 0000000000..b6b6ca9f7c
--- /dev/null
+++ b/devtools/client/webconsole/middleware/history-persistence.js
@@ -0,0 +1,71 @@
+/* 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 {
+  APPEND_TO_HISTORY,
+  CLEAR_HISTORY,
+  EVALUATE_EXPRESSION,
+} = require("resource://devtools/client/webconsole/constants.js");
+
+const historyActions = require("resource://devtools/client/webconsole/actions/history.js");
+
+loader.lazyRequireGetter(
+  this,
+  "asyncStorage",
+  "resource://devtools/shared/async-storage.js"
+);
+
+/**
+ * History persistence middleware is responsible for loading
+ * and maintaining history of executed expressions in JSTerm.
+ */
+function historyPersistenceMiddleware(webConsoleUI, store) {
+  let historyLoaded = false;
+  asyncStorage.getItem("webConsoleHistory").then(
+    value => {
+      if (Array.isArray(value)) {
+        store.dispatch(historyActions.historyLoaded(value));
+      }
+      historyLoaded = true;
+    },
+    err => {
+      historyLoaded = true;
+      console.error(err);
+    }
+  );
+
+  return next => action => {
+    const res = next(action);
+
+    const triggerStoreActions = [
+      APPEND_TO_HISTORY,
+      CLEAR_HISTORY,
+      EVALUATE_EXPRESSION,
+    ];
+
+    // Save the current history entries when modified, but wait till
+    // entries from the previous session are loaded.
+    const { isPrivate } =
+      webConsoleUI.hud?.commands?.targetCommand?.targetFront?.targetForm || {};
+
+    if (
+      !isPrivate &&
+      historyLoaded &&
+      triggerStoreActions.includes(action.type)
+    ) {
+      const state = store.getState();
+      asyncStorage
+        .setItem("webConsoleHistory", state.history.entries)
+        .catch(e => {
+          console.error("Error when saving WebConsole input history", e);
+        });
+    }
+
+    return res;
+  };
+}
+
+module.exports = historyPersistenceMiddleware;