Render threadables

app/javascript/extensions/array_extensions.js

@@ -0,0 +1,17 @@
+Array.prototype.toSentence = function() {
+  const length = this.length
+
+  switch (length) {
+    case 0:
+      return ""
+    case 1:
+      return `${this[0]}.`
+    case 2:
+      return `${this[0]} and ${this[1]}.`
+    default:
+      return this.map((item, index) => {
+        const isLast = index === length - 1
+        return isLast ? `and ${item}.` : item
+      }).join(", ")
+  }
+}