1 files changed, 60 insertions, 0 deletions
diff --git a/browser/components/migration/MigrationWizardParent.sys.mjs b/browser/components/migration/MigrationWizardParent.sys.mjs
new file mode 100644
index 0000000000..15120c8e09
--- /dev/null
+++ b/browser/components/migration/MigrationWizardParent.sys.mjs
@@ -0,0 +1,60 @@
+/* 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/. */
+
+import { MigrationUtils } from "resource:///modules/MigrationUtils.sys.mjs";
+import { E10SUtils } from "resource://gre/modules/E10SUtils.sys.mjs";
+
+/**
+ * This class is responsible for communicating with MigrationUtils to do the
+ * actual heavy-lifting of any kinds of migration work, based on messages from
+ * the associated MigrationWizardChild.
+ */
+export class MigrationWizardParent extends JSWindowActorParent {
+  /**
+   * General message handler function for messages received from the
+   * associated MigrationWizardChild JSWindowActor.
+   *
+   * @param {ReceiveMessageArgument} message
+   *   The message received from the MigrationWizardChild.
+   * @returns {Promise}
+   */
+  async receiveMessage(message) {
+    // Some belt-and-suspenders here, mainly because the migration-wizard
+    // component can be embedded in less privileged content pages, so let's
+    // make sure that any messages from content are coming from the privileged
+    // about content process type.
+    if (
+      !this.browsingContext.currentWindowGlobal.isInProcess &&
+      this.browsingContext.currentRemoteType !=
+        E10SUtils.PRIVILEGEDABOUT_REMOTE_TYPE
+    ) {
+      throw new Error(
+        "MigrationWizardParent: received message from the wrong content process type."
+      );
+    }
+
+    if (message.name == "GetAvailableMigrators") {
+      let availableMigrators = new Map();
+      for (const key of MigrationUtils.availableMigratorKeys) {
+        try {
+          let migratorPromise = MigrationUtils.getMigrator(key).catch(
+            console.error
+          );
+          if (migratorPromise) {
+            availableMigrators.set(key, migratorPromise);
+          }
+        } catch (e) {
+          console.error(`Could not get migrator with key ${key}`);
+        }
+      }
+      // Wait for all getMigrator calls to resolve in parallel
+      await Promise.all(availableMigrators.values());
+      // ...and then filter out any that resolved to null.
+      return Array.from(availableMigrators.keys()).filter(key => {
+        return availableMigrators.get(key);
+      });
+    }
+    return null;
+  }
+}