Fix tests

Author: javiercn

src/StaticWebAssetsSdk/Tasks/Data/StaticWebAssetEndpointProperty.cs

@@ -43,6 +43,7 @@ public static void PopulateFromMetadataValue(string value, List<StaticWebAssetEn
     {
         properties.Clear();
 
+        properties.Clear();
         if (string.IsNullOrEmpty(value))
         {
             return;

test/Microsoft.NET.Sdk.StaticWebAssets.Tests/StaticWebAssets/StaticWebAssetEndpointPropertyTest.cs

@@ -128,7 +128,7 @@ public void PopulateFromMetadataValue_MixedProperties_HandlesCorrectly()
     }
 
     [Fact]
-    public void PopulateFromMetadataValue_ExistingList_AppendsToList()
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_BeforeAppendingElements()
     {
         // Arrange
         var json = """[{"Name":"label","Value":"new-value"}]""";
@@ -141,11 +141,29 @@ public void PopulateFromMetadataValue_ExistingList_AppendsToList()
         StaticWebAssetEndpointProperty.PopulateFromMetadataValue(json, properties);
 
         // Assert
-        properties.Should().HaveCount(2);
-        properties[0].Name.Should().Be("existing");
-        properties[0].Value.Should().Be("existing-value");
-        properties[1].Name.Should().Be("label");
-        properties[1].Value.Should().Be("new-value");
+        properties.Should().HaveCount(1);
+        properties[0].Name.Should().Be("label");
+        properties[0].Value.Should().Be("new-value");
+    }
+
+    [Fact]
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_ValidatesClearingBehavior()
+    {
+        // Arrange
+        var json = """[{"Name":"newProp","Value":"newValue"}]""";
+        var properties = new List<StaticWebAssetEndpointProperty>
+        {
+            new() { Name = "existing1", Value = "existingValue1" },
+            new() { Name = "existing2", Value = "existingValue2" }
+        };
+
+        // Act
+        StaticWebAssetEndpointProperty.PopulateFromMetadataValue(json, properties);
+
+        // Assert - List should be cleared and contain only the new property
+        properties.Should().HaveCount(1);
+        properties[0].Name.Should().Be("newProp");
+        properties[0].Value.Should().Be("newValue");
     }
 
     [Fact]

test/Microsoft.NET.Sdk.StaticWebAssets.Tests/StaticWebAssets/StaticWebAssetEndpointResponseHeaderTest.cs

@@ -150,7 +150,7 @@ public void PopulateFromMetadataValue_MixedHeaders_HandlesCorrectly()
     }
 
     [Fact]
-    public void PopulateFromMetadataValue_ExistingList_AppendsToList()
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_BeforeAppendingElements()
     {
         // Arrange
         var json = """[{"Name":"Content-Type","Value":"application/json"}]""";
@@ -163,11 +163,29 @@ public void PopulateFromMetadataValue_ExistingList_AppendsToList()
         StaticWebAssetEndpointResponseHeader.PopulateFromMetadataValue(json, headers);
 
         // Assert
-        headers.Should().HaveCount(2);
-        headers[0].Name.Should().Be("X-Existing");
-        headers[0].Value.Should().Be("existing-value");
-        headers[1].Name.Should().Be("Content-Type");
-        headers[1].Value.Should().Be("application/json");
+        headers.Should().HaveCount(1);
+        headers[0].Name.Should().Be("Content-Type");
+        headers[0].Value.Should().Be("application/json");
+    }
+
+    [Fact]
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_ValidatesClearingBehavior()
+    {
+        // Arrange
+        var json = """[{"Name":"X-Custom","Value":"custom-value"}]""";
+        var headers = new List<StaticWebAssetEndpointResponseHeader>
+        {
+            new() { Name = "Content-Type", Value = "text/html" },
+            new() { Name = "Cache-Control", Value = "max-age=3600" }
+        };
+
+        // Act
+        StaticWebAssetEndpointResponseHeader.PopulateFromMetadataValue(json, headers);
+
+        // Assert - List should be cleared and contain only the new header
+        headers.Should().HaveCount(1);
+        headers[0].Name.Should().Be("X-Custom");
+        headers[0].Value.Should().Be("custom-value");
     }
 
     [Fact]

test/Microsoft.NET.Sdk.StaticWebAssets.Tests/StaticWebAssets/StaticWebAssetEndpointSelectorTest.cs

@@ -149,7 +149,7 @@ public void PopulateFromMetadataValue_MixedSelectors_HandlesCorrectly()
     }
 
     [Fact]
-    public void PopulateFromMetadataValue_ExistingList_AppendsToList()
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_BeforeAppendingElements()
     {
         // Arrange
         var json = """[{"Name":"Content-Encoding","Value":"gzip"}]""";
@@ -162,11 +162,29 @@ public void PopulateFromMetadataValue_ExistingList_AppendsToList()
         StaticWebAssetEndpointSelector.PopulateFromMetadataValue(json, selectors);
 
         // Assert
-        selectors.Should().HaveCount(2);
-        selectors[0].Name.Should().Be("Existing-Selector");
-        selectors[0].Value.Should().Be("existing-value");
-        selectors[1].Name.Should().Be("Content-Encoding");
-        selectors[1].Value.Should().Be("gzip");
+        selectors.Should().HaveCount(1);
+        selectors[0].Name.Should().Be("Content-Encoding");
+        selectors[0].Value.Should().Be("gzip");
+    }
+
+    [Fact]
+    public void PopulateFromMetadataValue_ExistingList_ClearsExistingItems_ValidatesClearingBehavior()
+    {
+        // Arrange
+        var json = """[{"Name":"Accept-Encoding","Value":"br"}]""";
+        var selectors = new List<StaticWebAssetEndpointSelector>
+        {
+            new() { Name = "Content-Encoding", Value = "gzip" },
+            new() { Name = "Content-Type", Value = "text/css" }
+        };
+
+        // Act
+        StaticWebAssetEndpointSelector.PopulateFromMetadataValue(json, selectors);
+
+        // Assert - List should be cleared and contain only the new selector
+        selectors.Should().HaveCount(1);
+        selectors[0].Name.Should().Be("Accept-Encoding");
+        selectors[0].Value.Should().Be("br");
     }
 
     [Fact]