ran npm run tdd & generated TDD

test/formatDuration/formatDuration.js

@@ -0,0 +1,14 @@
+module.exports = ms => {
+if (ms < 0) ms = -ms;
+const time = {
+day: Math.floor(ms / 86400000),
+hour: Math.floor(ms / 3600000) % 24,
+minute: Math.floor(ms / 60000) % 60,
+second: Math.floor(ms / 1000) % 60,
+millisecond: Math.floor(ms) % 1000
+};
+return Object.entries(time)
+.filter(val => val[1] !== 0)
+.map(val => val[1] + ' ' + (val[1] !== 1 ? val[0] + 's' : val[0]))
+.join(', ');
+};