1 files changed, 75 insertions, 0 deletions
diff --git a/packages/idb-bridge/src/util/deepEquals.ts b/packages/idb-bridge/src/util/deepEquals.ts
new file mode 100644
index 000000000..8d05ad21e
--- /dev/null
+++ b/packages/idb-bridge/src/util/deepEquals.ts
@@ -0,0 +1,75 @@
+/*
+Copyright (c) 2017 Evgeny Poberezkin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+
+
+
+const isArray = Array.isArray;
+const keyList = Object.keys;
+const hasProp = Object.prototype.hasOwnProperty;
+
+function deepEquals(a: any, b: any): boolean {
+  if (a === b) return true;
+
+  if (a && b && typeof a == "object" && typeof b == "object") {
+    const arrA = isArray(a);
+    const arrB = isArray(b);
+    let i;
+    let length;
+    let key;
+
+    if (arrA && arrB) {
+      length = a.length;
+      if (length != b.length) return false;
+      for (i = length; i-- !== 0; ) if (!deepEquals(a[i], b[i])) return false;
+      return true;
+    }
+
+    if (arrA != arrB) return false;
+
+    const dateA = a instanceof Date;
+    const dateB = b instanceof Date;
+    if (dateA != dateB) return false;
+    if (dateA && dateB) return a.getTime() == b.getTime();
+
+    const regexpA = a instanceof RegExp;
+    const regexpB = b instanceof RegExp;
+    if (regexpA != regexpB) return false;
+    if (regexpA && regexpB) return a.toString() == b.toString();
+
+    const keys = keyList(a);
+    length = keys.length;
+
+    if (length !== keyList(b).length) return false;
+
+    for (i = length; i-- !== 0; ) if (!hasProp.call(b, keys[i])) return false;
+
+    for (i = length; i-- !== 0; ) {
+      key = keys[i];
+      if (!deepEquals(a[key], b[key])) return false;
+    }
+
+    return true;
+  }
+
+  return a !== a && b !== b;
+}