bugfix: handled acessing last element of an empty queue

hbarcelos · Feb 5, 2020 · b478170b61f23b8ac8ed865624cfd22b3f6f68a0 · b478170
1 parent d67fdf6
commit b478170b61f23b8ac8ed865624cfd22b3f6f68a0
Showing 2 changed files with 10 additions and 0 deletions.
diff --git a/round-linked-queue.js b/round-linked-queue.js
@@ -25,6 +25,10 @@ class RoundLinkedQueue {
   }
 
   get last() {
+    if (!this._last) {
+      throw new Error("Cannot access the last element of an empty queue");
+    }
+
     return this._last.data;
   }
 

diff --git a/round-linked-queue.test.js b/round-linked-queue.test.js
@@ -122,5 +122,11 @@ describe("Round-Queue", () => {
 
       expect(() => queue.first).to.throw("Cannot access the first element of an empty queue");
     });
+
+    it("Should throw a proper error when acessing the last element of an empty queue", () => {
+      const queue = new RoundQueue(3);
+
+      expect(() => queue.last).to.throw("Cannot access the last element of an empty queue");
+    });
   });
 });