improve querystring handling

Author: mythz

src/ServiceStack.Text/HttpUtils.cs

@@ -21,17 +21,22 @@ public static class HttpUtils
 
         public static string AddQueryParam(this string url, string key, object val, bool encode = true)
         {
-            return url.AddQueryParam(key, val.ToString(), encode);
+            return url.AddQueryParam(key, val?.ToString(), encode);
         }
 
         public static string AddQueryParam(this string url, object key, string val, bool encode = true)
         {
-            return AddQueryParam(url, (key ?? "").ToString(), val, encode);
+            return AddQueryParam(url, key?.ToString(), val, encode);
         }
 
         public static string AddQueryParam(this string url, string key, string val, bool encode = true)
         {
-            if (string.IsNullOrEmpty(url)) return null;
+            if (url == null)
+                url = "";
+
+            if (key == null || val == null)
+                return url;
+            
             var prefix = string.Empty;
             if (!url.EndsWith("?") && !url.EndsWith("&"))
             {
@@ -42,7 +47,12 @@ public static string AddQueryParam(this string url, string key, string val, bool
 
         public static string SetQueryParam(this string url, string key, string val)
         {
-            if (string.IsNullOrEmpty(url)) return null;
+            if (url == null)
+                url = "";
+            
+            if (key == null || val == null)
+                return url;
+            
             var qsPos = url.IndexOf('?');
             if (qsPos != -1)
             {
@@ -69,19 +79,29 @@ public static string SetQueryParam(this string url, string key, string val)
 
         public static string AddHashParam(this string url, string key, object val)
         {
-            return url.AddHashParam(key, val.ToString());
+            return url.AddHashParam(key, val?.ToString());
         }
 
         public static string AddHashParam(this string url, string key, string val)
         {
-            if (string.IsNullOrEmpty(url)) return null;
+            if (url == null)
+                url = "";
+            
+            if (key == null || val == null)
+                return url;
+            
             var prefix = url.IndexOf('#') == -1 ? "#" : "/";
             return url + prefix + key + "=" + val.UrlEncode();
         }
 
         public static string SetHashParam(this string url, string key, string val)
         {
-            if (string.IsNullOrEmpty(url)) return null;
+            if (url == null)
+                url = "";
+            
+            if (key == null || val == null)
+                return url;
+            
             var hPos = url.IndexOf('#');
             if (hPos != -1)
             {

src/ServiceStack.Text/StringExtensions.cs

@@ -107,7 +107,8 @@ public static string DecodeJsv(this string value)
 
         public static string UrlEncode(this string text, bool upperCase=false)
         {
-            if (String.IsNullOrEmpty(text)) return text;
+            if (string.IsNullOrEmpty(text)) 
+                return text;
 
             var sb = StringBuilderThreadStatic.Allocate();
             var fmt = upperCase ? "X2" : "x2";

tests/ServiceStack.Text.Tests/HttpUtilsTests.cs

@@ -16,6 +16,13 @@ public void Can_AddQueryParam()
             Assert.That("http://example.com?".AddQueryParam("f", "1"), Is.EqualTo("http://example.com?f=1"));
             Assert.That("http://example.com?f=1&".AddQueryParam("f", "2"), Is.EqualTo("http://example.com?f=1&f=2"));
             Assert.That("http://example.com?ab=0".AddQueryParam("a", "1"), Is.EqualTo("http://example.com?ab=0&a=1"));
+            
+            Assert.That("".AddQueryParam("a", ""), Is.EqualTo("?a="));
+            Assert.That("".AddQueryParam("a", null), Is.EqualTo(""));
+            Assert.That("/".AddQueryParam("a", null), Is.EqualTo("/"));
+            Assert.That("/".AddQueryParam("a", ""), Is.EqualTo("/?a="));
+            Assert.That("/".AddQueryParam("a", "b"), Is.EqualTo("/?a=b"));
+            Assert.That((null as string).AddQueryParam("a", "b"), Is.EqualTo("?a=b"));
         }
 
         [Test]
@@ -38,6 +45,13 @@ public void Can_AddHashParam()
             Assert.That("http://example.com#s=0/f=1/s=1".AddHashParam("f", "2"), Is.EqualTo("http://example.com#s=0/f=1/s=1/f=2"));
             Assert.That("http://example.com#s=rf/f=1".AddHashParam("f", "2"), Is.EqualTo("http://example.com#s=rf/f=1/f=2"));
             Assert.That("http://example.com#ab=0".AddHashParam("a", "1"), Is.EqualTo("http://example.com#ab=0/a=1"));
+            
+            Assert.That("".AddHashParam("a", ""), Is.EqualTo("#a="));
+            Assert.That("".AddHashParam("a", null), Is.EqualTo(""));
+            Assert.That("/".AddHashParam("a", null), Is.EqualTo("/"));
+            Assert.That("/".AddHashParam("a", ""), Is.EqualTo("/#a="));
+            Assert.That("/".AddHashParam("a", "b"), Is.EqualTo("/#a=b"));
+            Assert.That((null as string).AddHashParam("a", "b"), Is.EqualTo("#a=b"));
         }
 
         [Test]