Some code cleanup, add jest coverage and begin using it for utility functions

resources/scripts/lib/helpers.ts

@@ -0,0 +1,17 @@
+/**
+ * Given a valid six character HEX color code, converts it into its associated
+ * RGBA value with a user controllable alpha channel.
+ */
+function hexToRgba (hex: string, alpha = 1): string {
+    // noinspection RegExpSimplifiable
+    if (!/#?([a-fA-F0-9]{2}){3}/.test(hex)) {
+        return hex;
+    }
+
+    // noinspection RegExpSimplifiable
+    const [ r, g, b ] = hex.match(/[a-fA-F0-9]{2}/g)!.map(v => parseInt(v, 16));
+
+    return `rgba(${r}, ${g}, ${b}, ${alpha})`;
+}
+
+export { hexToRgba };