From 03d3a84d1a1f8311a54fa20e0f935d8b6b0fd1be Mon Sep 17 00:00:00 2001
From: Matthew Edmondson <matthew.edmondson@gmail.com>
Date: Thu, 8 Oct 2026 22:35:03 +0000
Subject: [PATCH] Return every stacked block's properties from
 ExtractFrontmatter [patch]

ExtractBody, RemoveFrontmatter and AddFrontmatter treat consecutive
frontmatter blocks as one header, but ExtractFrontmatter returned only the
first block, so a later block's properties were in neither the extracted
frontmatter nor the body. Fold every block the way AddFrontmatter does, so
the first block to define a key wins.

Fixes #169

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019MupvoiQ9WM1vUJoCzYJ6W
---
 .../StackedBlockPreservationTests.cs          | 25 +++++++++++++++++++
 Frontmatter/Frontmatter.cs                    | 10 ++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/Frontmatter.Test/StackedBlockPreservationTests.cs b/Frontmatter.Test/StackedBlockPreservationTests.cs
index 480af95..c1410a4 100644
--- a/Frontmatter.Test/StackedBlockPreservationTests.cs
+++ b/Frontmatter.Test/StackedBlockPreservationTests.cs
@@ -41,6 +41,31 @@ public void AddFrontmatter_StackedBlocksRepeatAKey_FirstBlockWins()
 		Assert.AreEqual("First", frontmatter["title"]);
 	}
 
+	[TestMethod]
+	public void ExtractFrontmatter_TwoStackedBlocks_ReturnsPropertiesFromEveryBlock()
+	{
+		const string input = "---\ntitle: Hello\n---\n---\nauthor: Jane\n---\n# Body\n";
+
+		Dictionary<string, object>? frontmatter = Frontmatter.ExtractFrontmatter(input);
+
+		Assert.IsNotNull(frontmatter);
+		Assert.AreEqual("Hello", frontmatter["title"]);
+		Assert.AreEqual("Jane", frontmatter["author"], "The second block is header to ExtractBody, so ExtractFrontmatter must return it");
+		Assert.AreEqual("# Body", Frontmatter.ExtractBody(input));
+	}
+
+	[TestMethod]
+	public void ExtractFrontmatter_StackedBlocksRepeatAKey_FirstBlockWins()
+	{
+		const string input = "---\ntitle: First\n---\n---\ntitle: Second\nauthor: Jane\n---\nbody\n";
+
+		Dictionary<string, object>? frontmatter = Frontmatter.ExtractFrontmatter(input);
+
+		Assert.IsNotNull(frontmatter);
+		Assert.AreEqual("First", frontmatter["title"]);
+		Assert.AreEqual("Jane", frontmatter["author"]);
+	}
+
 	// The first block is always read as frontmatter, so an unparseable first block followed by one that
 	// parses is the case where the unreadable text sits in the header rather than the body.
 	private const string UnreadableFirstBlock = "---\nkey: [unclosed\n---\n---\ntitle: T\n---\nbody\n";
diff --git a/Frontmatter/Frontmatter.cs b/Frontmatter/Frontmatter.cs
index 9907721..1cdba09 100644
--- a/Frontmatter/Frontmatter.cs
+++ b/Frontmatter/Frontmatter.cs
@@ -126,6 +126,10 @@ public static string CombineFrontmatter(string input, FrontmatterNaming property
 	/// Extracts frontmatter from a markdown document.
 	/// </summary>
 	/// <param name="input">The markdown document content as a string.</param>
+	/// <remarks>
+	/// Consecutive frontmatter blocks form one header, so their properties are combined, and the first
+	/// block to define a key wins.
+	/// </remarks>
 	/// <returns>A dictionary containing the frontmatter properties, or null if no frontmatter is found.</returns>
 	/// <exception cref="ArgumentNullException">Thrown when input is null.</exception>
 	public static Dictionary<string, object>? ExtractFrontmatter(string input)
@@ -137,8 +141,10 @@ public static string CombineFrontmatter(string input, FrontmatterNaming property
 			return null;
 		}
 
-		List<Dictionary<string, object>> frontmatterObjects = ExtractFrontmatterObjects(input, out _);
-		return frontmatterObjects.Count > 0 ? frontmatterObjects.First() : null;
+		// Stacked blocks are one header, as AddFrontmatter and ExtractBody treat them, so fold them all
+		// and let an earlier block win a repeated key.
+		Dictionary<string, object> frontmatter = CombineAllFrontmatterObjects(ExtractFrontmatterObjects(input, out _));
+		return frontmatter.Count > 0 ? frontmatter : null;
 	}
 
 	/// <summary>