v3 new release (#80)

node_modules/underscore/modules/_methodFingerprint.js

@@ -0,0 +1,37 @@
+import getLength from './_getLength.js';
+import isFunction from './isFunction.js';
+import allKeys from './allKeys.js';
+
+// Since the regular `Object.prototype.toString` type tests don't work for
+// some types in IE 11, we use a fingerprinting heuristic instead, based
+// on the methods. It's not great, but it's the best we got.
+// The fingerprint method lists are defined below.
+export function ie11fingerprint(methods) {
+  var length = getLength(methods);
+  return function(obj) {
+    if (obj == null) return false;
+    // `Map`, `WeakMap` and `Set` have no enumerable keys.
+    var keys = allKeys(obj);
+    if (getLength(keys)) return false;
+    for (var i = 0; i < length; i++) {
+      if (!isFunction(obj[methods[i]])) return false;
+    }
+    // If we are testing against `WeakMap`, we need to ensure that
+    // `obj` doesn't have a `forEach` method in order to distinguish
+    // it from a regular `Map`.
+    return methods !== weakMapMethods || !isFunction(obj[forEachName]);
+  };
+}
+
+// In the interest of compact minification, we write
+// each string in the fingerprints only once.
+var forEachName = 'forEach',
+    hasName = 'has',
+    commonInit = ['clear', 'delete'],
+    mapTail = ['get', hasName, 'set'];
+
+// `Map`, `WeakMap` and `Set` each have slightly different
+// combinations of the above sublists.
+export var mapMethods = commonInit.concat(forEachName, mapTail),
+    weakMapMethods = commonInit.concat(mapTail),
+    setMethods = ['add'].concat(commonInit, forEachName, hasName);