Initial data commit

Task/Factorial/JavaScript/factorial-7.js

@@ -0,0 +1,28 @@
+(() => {
+    'use strict';
+
+    // factorial :: Int -> Int
+    const factorial = n =>
+        enumFromTo(1, n)
+        .reduce(product, 1);
+
+
+    const test = () =>
+        factorial(18);
+    // --> 6402373705728000
+
+
+    // GENERIC FUNCTIONS ----------------------------------
+
+    // product :: Num -> Num -> Num
+    const product = (a, b) => a * b;
+
+    // range :: Int -> Int -> [Int]
+    const enumFromTo = (m, n) =>
+        Array.from({
+            length: (n - m) + 1
+        }, (_, i) => m + i);
+
+    // MAIN ------
+    return test();
+})();