From f15a136e00cbd741cf92f9d9a3cd239151d66b1a Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sat, 17 Sep 2016 20:46:48 +0200
Subject: [PATCH] Throw an exception if FontWeight <= 0

In FormattedText. Fixes #700.
---
 .../Media/FormattedText.cs                    | 11 +++++++-
 .../Media/FormattedTextTests.cs               | 28 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 tests/Avalonia.SceneGraph.UnitTests/Media/FormattedTextTests.cs

diff --git a/src/Avalonia.SceneGraph/Media/FormattedText.cs b/src/Avalonia.SceneGraph/Media/FormattedText.cs
index 1169a56343..f6aeaf5f5f 100644
--- a/src/Avalonia.SceneGraph/Media/FormattedText.cs
+++ b/src/Avalonia.SceneGraph/Media/FormattedText.cs
@@ -33,7 +33,16 @@ namespace Avalonia.Media
         {
             Contract.Requires<ArgumentNullException>(text != null);
             Contract.Requires<ArgumentNullException>(fontFamilyName != null);
-            Contract.Requires<ArgumentException>(fontSize > 0);
+
+            if (fontSize <= 0)
+            {
+                throw new ArgumentException("FontSize must be greater than 0");
+            }
+
+            if (fontWeight <= 0)
+            {
+                throw new ArgumentException("FontWeight must be greater than 0");
+            }
 
             Text = text;
             FontFamilyName = fontFamilyName;
diff --git a/tests/Avalonia.SceneGraph.UnitTests/Media/FormattedTextTests.cs b/tests/Avalonia.SceneGraph.UnitTests/Media/FormattedTextTests.cs
new file mode 100644
index 0000000000..d36e23a6d8
--- /dev/null
+++ b/tests/Avalonia.SceneGraph.UnitTests/Media/FormattedTextTests.cs
@@ -0,0 +1,28 @@
+using System;
+using Avalonia.Media;
+using Xunit;
+
+namespace Avalonia.SceneGraph.UnitTests.Media
+{
+    public class FormattedTextTests
+    {
+        [Fact]
+        public void Exception_Should_Be_Thrown_If_FontSize_0()
+        {
+            Assert.Throws<ArgumentException>(() => new FormattedText(
+                "foo",
+                "Ariel",
+                0));
+        }
+
+        [Fact]
+        public void Exception_Should_Be_Thrown_If_FontWeight_0()
+        {
+            Assert.Throws<ArgumentException>(() => new FormattedText(
+                "foo",
+                "Ariel",
+                12,
+                fontWeight: 0));
+        }
+    }
+}