--- /dev/null
+var baseIteratee = require('./_baseIteratee'),
+ baseSortedIndexBy = require('./_baseSortedIndexBy');
+
+/**
+ * This method is like `_.sortedIndex` except that it accepts `iteratee`
+ * which is invoked for `value` and each element of `array` to compute their
+ * sort ranking. The iteratee is invoked with one argument: (value).
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category Array
+ * @param {Array} array The sorted array to inspect.
+ * @param {*} value The value to evaluate.
+ * @param {Function} [iteratee=_.identity] The iteratee invoked per element.
+ * @returns {number} Returns the index at which `value` should be inserted
+ * into `array`.
+ * @example
+ *
+ * var objects = [{ 'x': 4 }, { 'x': 5 }];
+ *
+ * _.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
+ * // => 0
+ *
+ * // The `_.property` iteratee shorthand.
+ * _.sortedIndexBy(objects, { 'x': 4 }, 'x');
+ * // => 0
+ */
+function sortedIndexBy(array, value, iteratee) {
+ return baseSortedIndexBy(array, value, baseIteratee(iteratee, 2));
+}
+
+module.exports = sortedIndexBy;