From 26ec36d5f34e7fc52169509a5b366a88f10a593b Mon Sep 17 00:00:00 2001
From: Marcus Jaschen <mjaschen@gmail.com>
Date: Fri, 22 Mar 2019 08:22:41 +0100
Subject: [PATCH] add exception message

---
 src/Formatter/Polygon/GeoJSON.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Formatter/Polygon/GeoJSON.php b/src/Formatter/Polygon/GeoJSON.php
index 59a184a..3d06c57 100644
--- a/src/Formatter/Polygon/GeoJSON.php
+++ b/src/Formatter/Polygon/GeoJSON.php
@@ -24,8 +24,9 @@ class GeoJSON implements FormatterInterface
     public function format(Polygon $polygon): string
     {
         if ($polygon->getNumberOfPoints() < 3) {
-            throw new InvalidPolygonException();
+            throw new InvalidPolygonException('A polygon must consist of at least three points.');
         }
+
         $points = [];
 
         /** @var Coordinate $point */
@@ -35,7 +36,7 @@ public function format(Polygon $polygon): string
 
         return json_encode(
             [
-                'type'        => 'Polygon',
+                'type' => 'Polygon',
                 'coordinates' => [$points],
             ]
         );