From 0d956c225399e0e4af9ad16785fa426efdaeeda2 Mon Sep 17 00:00:00 2001
From: Alex Rock Ancelet <pierstoval@gmail.com>
Date: Wed, 18 Dec 2019 08:45:00 +0100
Subject: [PATCH] Make sure graph vertex value is converted to string

---
 src/data-structures/graph/GraphVertex.js         |  2 +-
 .../graph/__test__/GraphVertex.test.js           | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/data-structures/graph/GraphVertex.js b/src/data-structures/graph/GraphVertex.js
index f11dd2c1..f3514d44 100644
--- a/src/data-structures/graph/GraphVertex.js
+++ b/src/data-structures/graph/GraphVertex.js
@@ -133,6 +133,6 @@ export default class GraphVertex {
    * @returns {string}
    */
   toString(callback) {
-    return callback ? callback(this.value) : `${this.value}`;
+    return callback ? callback(this.value).toString() : this.value.toString();
   }
 }
diff --git a/src/data-structures/graph/__test__/GraphVertex.test.js b/src/data-structures/graph/__test__/GraphVertex.test.js
index 4810a1c2..3fc2110d 100644
--- a/src/data-structures/graph/__test__/GraphVertex.test.js
+++ b/src/data-structures/graph/__test__/GraphVertex.test.js
@@ -185,4 +185,20 @@ describe('GraphVertex', () => {
 
     expect(vertexA.getEdges().length).toEqual(3);
   });
+
+  it('should execute callback when passed to toString', () => {
+    const vertex = new GraphVertex('A');
+
+    expect(vertex.toString(() => 'B')).toEqual('B');
+  });
+
+  it('should execute toString on value when calling toString on vertex', () => {
+    const value = {
+      toString() { return 'A'; },
+    };
+
+    const vertex = new GraphVertex(value);
+
+    expect(vertex.toString()).toEqual('A');
+  });
 });