1 files changed, 123 insertions, 0 deletions
diff --git a/devtools/client/dom/content/reducers/grips.js b/devtools/client/dom/content/reducers/grips.js
new file mode 100644
index 0000000000..acfb1146f2
--- /dev/null
+++ b/devtools/client/dom/content/reducers/grips.js
@@ -0,0 +1,123 @@
+/* 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 constants = require("devtools/client/dom/content/constants");
+
+/**
+ * Initial state definition
+ */
+function getInitialState() {
+  return new Map();
+}
+
+/**
+ * Maintain a cache of received grip responses from the backend.
+ */
+function grips(state = getInitialState(), action) {
+  // This reducer supports only one action, fetching actor properties
+  // from the backend so, bail out if we are dealing with any other
+  // action.
+  if (action.type != constants.FETCH_PROPERTIES) {
+    return state;
+  }
+
+  switch (action.status) {
+    case "start":
+      return onRequestProperties(state, action);
+    case "end":
+      return onReceiveProperties(state, action);
+  }
+
+  return state;
+}
+
+/**
+ * Handle requestProperties action
+ */
+function onRequestProperties(state, action) {
+  return state;
+}
+
+/**
+ * Handle receiveProperties action
+ */
+function onReceiveProperties(cache, action) {
+  const response = action.response;
+  const from = response.from;
+  const className = action.grip?.getGrip
+    ? action.grip.getGrip().class
+    : action.grip.class;
+
+  // Properly deal with getters.
+  mergeProperties(response);
+
+  // Compute list of requested children.
+  const previewProps = response.preview ? response.preview.ownProperties : null;
+  const ownProps = response.ownProperties || previewProps || [];
+
+  const props = Object.keys(ownProps).map(key => {
+    // Array indexes as a special case. We convert any keys that are string
+    // representations of integers to integers.
+    if (className === "Array" && isInteger(key)) {
+      key = parseInt(key, 10);
+    }
+    return new Property(key, ownProps[key], key);
+  });
+
+  props.sort(sortName);
+
+  // Return new state/map.
+  const newCache = new Map(cache);
+  newCache.set(from, props);
+
+  return newCache;
+}
+
+// Helpers
+
+function mergeProperties(response) {
+  const { ownProperties } = response;
+
+  // 'safeGetterValues' is new and isn't necessary defined on old grips.
+  const safeGetterValues = response.safeGetterValues || {};
+
+  // Merge the safe getter values into one object such that we can use it
+  // in variablesView.
+  for (const name of Object.keys(safeGetterValues)) {
+    if (name in ownProperties) {
+      const { getterValue, getterPrototypeLevel } = safeGetterValues[name];
+      ownProperties[name].getterValue = getterValue;
+      ownProperties[name].getterPrototypeLevel = getterPrototypeLevel;
+    } else {
+      ownProperties[name] = safeGetterValues[name];
+    }
+  }
+}
+
+function sortName(a, b) {
+  // Display non-enumerable properties at the end.
+  if (!a.value.enumerable && b.value.enumerable) {
+    return 1;
+  }
+  if (a.value.enumerable && !b.value.enumerable) {
+    return -1;
+  }
+  return a.name > b.name ? 1 : -1;
+}
+
+function isInteger(n) {
+  // We use parseInt(n, 10) == n to disregard scientific notation e.g. "3e24"
+  return isFinite(n) && parseInt(n, 10) == n;
+}
+
+function Property(name, value, key) {
+  this.name = name;
+  this.value = value;
+  this.key = key;
+}
+
+// Exports from this module
+exports.grips = grips;
+exports.Property = Property;