bugfix: handled acessing first element of an empty queue

hbarcelos · Feb 5, 2020 · d67fdf6 · d67fdf6
1 parent f4f8c9a
commit d67fdf6
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diff --git a/round-linked-queue.js b/round-linked-queue.js
@@ -17,6 +17,10 @@ class RoundLinkedQueue {
   }
 
   get first() {
+    if (!this._first) {
+      throw new Error("Cannot access the first element of an empty queue");
+    }
+
     return this._first.data;
   }
 

diff --git a/round-linked-queue.test.js b/round-linked-queue.test.js
@@ -115,4 +115,12 @@ describe("Round-Queue", () => {
       expect(() => queue.remove()).to.throw("Cannot remove element from an empty queue");
     });
   });
+
+  describe("When accessing elements", () => {
+    it("Should throw a proper error when acessing the first element of an empty queue", () => {
+      const queue = new RoundQueue(3);
+
+      expect(() => queue.first).to.throw("Cannot access the first element of an empty queue");
+    });
+  });
 });