Add class method and tests for p5.Vector.toString()

src/math/p5.Vector.js

@@ -2364,4 +2364,23 @@ p5.Vector.normalize = function normalize(v, target) {
   return target.normalize();
 };
 
+/**
+ * Returns a string representation of a vector v. This method is useful for
+ * logging vectors in the console.
+ * Note that the static method p5.Vector.toString() overrides the existing
+ * inherited method Function.prototype.toString().
+ */
+/**
+ * @method toString
+ * @static
+ * @param  {p5.Vector}    v the vector to stringify
+ * @return {String}       the string representation
+ */
+p5.Vector.toString = function toString(v) {
+  // NOTE: Returning `v.toString()` directly here will cause test cases such as
+  //       `assert.instanceOf(v, p5.Vector)` that check if something is an instance
+  //       of a p5.Vector to fail. Using `String(v)` as a workaround.
+  return String(v);
+};
+
 export default p5.Vector;

test/unit/math/p5.Vector.js

@@ -58,7 +58,7 @@ suite('p5.Vector', function() {
     setup(function() {
       v = new p5.Vector();
     });
-    test('should set constant to DEGREES', function() {
+    test('should create instance of p5.Vector', function() {
       assert.instanceOf(v, p5.Vector);
     });
 
@@ -1288,4 +1288,29 @@ suite('p5.Vector', function() {
       );
     });
   });
+
+  suite('toString', function() {
+    let v, vString;
+
+    setup(function() {
+      v = new p5.Vector(0, -1, 1);
+      vString = 'p5.Vector Object : [0, -1, 1]';
+    });
+
+    suite('p5.Vector.prototype.toString() [INSTANCE]', function() {
+      test('v.toString() should return "p5.Vector Object : [0, -1, 1]"', function() {
+        expect(v.toString()).to.equal(vString);
+      });
+
+      test('String(v) should return "p5.Vector Object : [0, -1, 1]"', function() {
+        expect(String(v)).to.equal(vString);
+      });
+    });
+
+    suite('p5.Vector.toString() [CLASS]', function() {
+      test('p5.Vector.toString(v) should return "p5.Vector Object : [0, -1, 1]"', function() {
+        expect(p5.Vector.toString(v)).to.equal(vString);
+      });
+    });
+  });
 });