Test migration to jest by hand

Apparently using regular expressions is way easier.

test/isArmstrongNumber/isArmstrongNumber.js

@@ -0,0 +1,5 @@
+const isArmstrongNumber = digits =>
+(arr => arr.reduce((a, d) => a + parseInt(d) ** arr.length, 0) == digits)(
+(digits + '').split('')
+);
+module.exports = isArmstrongNumber;