added assert tests for getCardValue

Author: Zadri415

Sprint-3/1-implement-and-rewrite-tests/implement/3-get-card-value.js

@@ -22,7 +22,41 @@
 // execute the code to ensure all tests pass.
 
 function getCardValue(card) {
-  // TODO: Implement this function
+  // Student-friendly step-by-step parsing and validation.
+  // 1) Expect a string like "A♠", "10♥", "K♦" where the last character is the suit emoji
+  // 2) The rank is everything before the final character (so "10" or "A")
+  // 3) Check the suit is one of the four allowed suits, and the rank is valid
+
+  if (typeof card !== "string") {
+    throw new Error('Card must be a string, e.g. "A♠"');
+  }
+
+  const text = card.trim();
+  if (text.length < 2) {
+    throw new Error(
+      'Invalid card: too short. Expect a rank and a suit, e.g. "10♠"'
+    );
+  }
+
+  // The suit is the last character, the rank is the rest
+  const suit = text[text.length - 1];
+  const rank = text.slice(0, -1);
+
+  const validSuits = new Set(["♠", "♥", "♦", "♣"]);
+  if (!validSuits.has(suit)) {
+    throw new Error(`Invalid suit "${suit}". Use one of: ♠ ♥ ♦ ♣`);
+  }
+
+  // Handle special ranks first
+  if (rank === "A") return 11;
+  if (rank === "J" || rank === "Q" || rank === "K") return 10;
+
+  // Otherwise expect a number between 2 and 10
+  const n = Number(rank);
+  if (Number.isInteger(n) && n >= 2 && n <= 10) return n;
+
+  // If we get here, the rank wasn't recognised
+  throw new Error(`Invalid rank "${rank}". Use A, 2-10, J, Q or K`);
 }
 
 // The line below allows us to load the getCardValue function into tests in other files.
@@ -52,3 +86,26 @@ try {
 }
 
 // What other invalid card cases can you think of?
+
+// === Student-friendly examples ===
+// These examples show how the function behaves. Run the file with node to see messages.
+console.log("\nRunning student-friendly examples for getCardValue:");
+
+// Good cards
+console.log("A♠ =>", getCardValue("A♠"), "(expected 11)");
+console.log("K♦ =>", getCardValue("K♦"), "(expected 10)");
+console.log("10♥ =>", getCardValue("10♥"), "(expected 10)");
+console.log("3♣ =>", getCardValue("3♣"), "(expected 3)");
+
+// Examples that should throw (wrapped in try/catch so the script keeps running)
+const examples = ["invalid", "9x", "a♠", ""];
+examples.forEach((example) => {
+  try {
+    const v = getCardValue(example);
+    console.log(`${example} => ${v} (unexpected: should have thrown)`);
+  } catch (e) {
+    console.log(`${example} => throws: ${e.message}`);
+  }
+});
+
+console.log("\nCompleted student-friendly examples");