bugfix: handled acessing last element of an empty queue

hbarcelos · hbarcelos · commit b478170b61f2 · 2020-02-05T14:34:48.000-03:00
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");
+    });
   });
 });

Original file line number	Diff line number	Diff line change
`@@ -25,6 +25,10 @@ class RoundLinkedQueue {`
`25`	`25`	`}`
`26`	`26`
`27`	`27`	`get last() {`
	`28`	`+ if (!this._last) {`
	`29`	`+ throw new Error("Cannot access the last element of an empty queue");`
	`30`	`+ }`
	`31`	`+`
`28`	`32`	`return this._last.data;`
`29`	`33`	`}`
`30`	`34`