client: Add withinRange

1 files changed, 11 insertions, 0 deletions

diff --git a/src/client/react/lib/withinRange.js b/src/client/react/lib/withinRange.js
new file mode 100644
index 0000000..d3d4f24
--- /dev/null
+++ b/src/client/react/lib/withinRange.js
@@ -0,0 +1,11 @@
+export default function withinRange(number, rangeMax) {
+  if (number < 0) {
+    return withinRange(number + (rangeMax + 1), rangeMax);
+  }
+
+  if (number > rangeMax) {
+    return withinRange(number - (rangeMax + 1), rangeMax);
+  }
+
+  return number;
+}