#370 SetQueryParams bug with duplicate keys

tmenier · Sep 15, 2023 · 69b3b1c · 69b3b1c
1 parent 29df951
commit 69b3b1c
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/Test/Flurl.Test/UrlBuilder/UrlBuildingTests.cs b/Test/Flurl.Test/UrlBuilder/UrlBuildingTests.cs
@@ -199,7 +199,7 @@ public void can_set_query_params_from_dictionary() {
 			Assert.AreEqual("http://www.mysite.com?1=x&2=y", url.ToString());
 		}
 
-		[Test, Ignore("tricky to do while maintaining param order. deferring until append param w/o overwriting is fully supported.")]
+		[Test]
 		public void can_set_query_params_from_kv_pairs() {
 			var url = "http://foo.com".SetQueryParams(new[] {
 				new { key = "x", value = 1 },

diff --git a/src/Flurl/Url.cs b/src/Flurl/Url.cs
@@ -372,8 +372,13 @@ public Url SetQueryParams(object values, NullValueHandling nullValueHandling = N
 			if (values is string s)
 				return SetQueryParam(s);
 
-			foreach (var kv in values.ToKeyValuePairs())
-				SetQueryParam(kv.Key, kv.Value, nullValueHandling);
+			var visited = new HashSet<string>();
+			foreach (var kv in values.ToKeyValuePairs()) {
+				if (visited.Add(kv.Key))
+					SetQueryParam(kv.Key, kv.Value, nullValueHandling); // overwrite existing key(s)
+				else
+					AppendQueryParam(kv.Key, kv.Value, nullValueHandling); // unless they're in this same collection (#370)
+			}
 
 			return this;
 		}