Secret handshake

typescript/secret-handshake/secret-handshake.ts

@@ -0,0 +1,54 @@
+const responses = ["wink", "double blink", "close your eyes", "jump"] as const;
+
+export function commands(secret: Secret): Response[] {
+  if (secret < 1 || secret > 31) {
+    return [];
+  }
+
+  const result = secret
+    .toString(2)
+    .split("")
+    .reverse()
+    .map((s, i) => (s === "1" ? responses[i] : null))
+    .filter(Boolean);
+
+  if (secret >= 16) {
+    return result.reverse() as Response[];
+  }
+  return result as Response[];
+}
+
+type Secret =
+  | 1
+  | 2
+  | 3
+  | 4
+  | 5
+  | 6
+  | 7
+  | 8
+  | 9
+  | 10
+  | 11
+  | 12
+  | 13
+  | 14
+  | 15
+  | 16
+  | 17
+  | 18
+  | 19
+  | 20
+  | 21
+  | 22
+  | 23
+  | 24
+  | 25
+  | 26
+  | 27
+  | 28
+  | 29
+  | 30
+  | 31;
+
+type Response = typeof responses[number];