import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

devtools/client/shared/redux/middleware/task.js

@@ -0,0 +1,42 @@
+/* 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 { Task } = require("devtools/shared/task");
+const { executeSoon, isGenerator, reportException } = require("devtools/shared/DevToolsUtils");
+const ERROR_TYPE = exports.ERROR_TYPE = "@@redux/middleware/task#error";
+
+/**
+ * A middleware that allows generator thunks (functions) and promise
+ * to be dispatched. If it's a generator, it is called with `dispatch`
+ * and `getState`, allowing the action to create multiple actions (most likely
+ * asynchronously) and yield on each. If called with a promise, calls `dispatch`
+ * on the results.
+ */
+
+function task({ dispatch, getState }) {
+  return next => action => {
+    if (isGenerator(action)) {
+      return Task.spawn(action.bind(null, dispatch, getState))
+        .then(null, handleError.bind(null, dispatch));
+    }
+
+    /*
+    if (isPromise(action)) {
+      return action.then(dispatch, handleError.bind(null, dispatch));
+    }
+    */
+
+    return next(action);
+  };
+}
+
+function handleError(dispatch, error) {
+  executeSoon(() => {
+    reportException(ERROR_TYPE, error);
+    dispatch({ type: ERROR_TYPE, error });
+  });
+}
+
+exports.task = task;