[2.x] Keep only partial data in mergeProps

inertiajs/inertia-laravel#745

Author: adrum

InertiaCore/Response.cs

@@ -159,13 +159,32 @@ protected internal async Task ProcessResponse()
            StringComparer.OrdinalIgnoreCase
        );
 
+        // Parse the "PARTIAL_ONLY" header into a collection of keys to include
+        var onlyProps = _context!.HttpContext.Request.Headers[InertiaHeader.PartialOnly]
+            .ToString()
+            .Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
+            .Select(s => s.Trim())
+            .Where(s => !string.IsNullOrEmpty(s))
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
+        // Parse the "PARTIAL_EXCEPT" header into a collection of keys to exclude
+        var exceptProps = new HashSet<string>(
+            _context!.HttpContext.Request.Headers[InertiaHeader.PartialExcept]
+                .ToString()
+                .Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
+                .Select(s => s.Trim()),
+            StringComparer.OrdinalIgnoreCase
+        );
+
         var resolvedProps = props
             .Select(kv => kv.Key.ToCamelCase()) // Convert property name to camelCase
             .ToList();
 
         // Filter the props that are Mergeable and should be merged
         var mergeProps = _props.Where(o => o.Value is Mergeable mergeable && mergeable.ShouldMerge()) // Check if value is Mergeable and should merge
             .Where(kv => !resetProps.Contains(kv.Key)) // Exclude reset keys
+            .Where(kv => onlyProps.Count == 0 || onlyProps.Contains(kv.Key)) // Include only specified keys if any
+            .Where(kv => !exceptProps.Contains(kv.Key)) // Exclude specified keys
             .Select(kv => kv.Key.ToCamelCase()) // Convert property name to camelCase
             .Where(resolvedProps.Contains) // Filter only the props that are in the resolved props
             .ToList();

InertiaCoreTests/UnitTestMergeData.cs

@@ -206,4 +206,116 @@ public async Task TestNoMergeProps()
         Assert.That(page?.MergeProps, Is.EqualTo(null));
     }
 
+    [Test]
+    [Description("Test if merge props are excluded when using PARTIAL_EXCEPT header.")]
+    public async Task TestMergePropsWithPartialExcept()
+    {
+        var response = _factory.Render("Test/Page", new
+        {
+            Test = "Test",
+            TestMerge1 = _factory.Merge(() => "Merge1"),
+            TestMerge2 = _factory.Merge(() => "Merge2"),
+            TestNormal = "Normal"
+        });
+
+        var headers = new HeaderDictionary
+        {
+            { "X-Inertia-Partial-Except", "testMerge1" },
+            { "X-Inertia-Partial-Component", "Test/Page" }
+        };
+
+        var context = PrepareContext(headers);
+
+        response.SetContext(context);
+        await response.ProcessResponse();
+
+        var page = response.GetJson().Value as Page;
+
+        Assert.That(page?.Props, Is.EqualTo(new Dictionary<string, object?>
+        {
+            { "test", "Test" },
+            { "testMerge2", "Merge2" },
+            { "testNormal", "Normal" },
+            { "errors", new Dictionary<string, string>(0) }
+        }));
+
+        // testMerge1 should be excluded from merge props due to PARTIAL_EXCEPT header
+        Assert.That(page?.MergeProps, Is.EqualTo(new List<string> { "testMerge2" }));
+    }
+
+    [Test]
+    [Description("Test if only specified merge props are included when using PARTIAL_ONLY header.")]
+    public async Task TestMergePropsWithPartialOnly()
+    {
+        var response = _factory.Render("Test/Page", new
+        {
+            Test = "Test",
+            TestMerge1 = _factory.Merge(() => "Merge1"),
+            TestMerge2 = _factory.Merge(() => "Merge2"),
+            TestNormal = "Normal"
+        });
+
+        var headers = new HeaderDictionary
+        {
+            { "X-Inertia-Partial-Data", "testMerge1,testNormal" },
+            { "X-Inertia-Partial-Component", "Test/Page" }
+        };
+
+        var context = PrepareContext(headers);
+
+        response.SetContext(context);
+        await response.ProcessResponse();
+
+        var page = response.GetJson().Value as Page;
+
+        Assert.That(page?.Props, Is.EqualTo(new Dictionary<string, object?>
+        {
+            { "testMerge1", "Merge1" },
+            { "testNormal", "Normal" },
+            { "errors", new Dictionary<string, string>(0) }
+        }));
+
+        // Only testMerge1 should be in merge props since testMerge2 was not included in PARTIAL_ONLY
+        Assert.That(page?.MergeProps, Is.EqualTo(new List<string> { "testMerge1" }));
+    }
+
+    [Test]
+    [Description("Test if merge props respect both PARTIAL_ONLY and PARTIAL_EXCEPT headers.")]
+    public async Task TestMergePropsWithPartialOnlyAndExcept()
+    {
+        var response = _factory.Render("Test/Page", new
+        {
+            Test = "Test",
+            TestMerge1 = _factory.Merge(() => "Merge1"),
+            TestMerge2 = _factory.Merge(() => "Merge2"),
+            TestMerge3 = _factory.Merge(() => "Merge3"),
+            TestNormal = "Normal"
+        });
+
+        var headers = new HeaderDictionary
+        {
+            { "X-Inertia-Partial-Data", "testMerge1,testMerge2,testMerge3,testNormal" },
+            { "X-Inertia-Partial-Except", "testMerge2" },
+            { "X-Inertia-Partial-Component", "Test/Page" }
+        };
+
+        var context = PrepareContext(headers);
+
+        response.SetContext(context);
+        await response.ProcessResponse();
+
+        var page = response.GetJson().Value as Page;
+
+        Assert.That(page?.Props, Is.EqualTo(new Dictionary<string, object?>
+        {
+            { "testMerge1", "Merge1" },
+            { "testMerge3", "Merge3" },
+            { "testNormal", "Normal" },
+            { "errors", new Dictionary<string, string>(0) }
+        }));
+
+        // testMerge1 and testMerge3 should be in merge props (testMerge2 excluded by PARTIAL_EXCEPT)
+        Assert.That(page?.MergeProps, Is.EqualTo(new List<string> { "testMerge1", "testMerge3" }));
+    }
+
 }