fix: trailing YAML comments in front matter (zig-yaml 0.3.1)

CHANGELOG.md

@@ -10,6 +10,15 @@ same stability guarantee.
 
 ## [0.9.0] — 2026-07-16
 
+### Fixed
+
+- **A trailing `# comment` after a plain scalar no longer breaks front-matter
+  parsing.** YAML like `- date: 2025-01-01  # when` inside a block sequence
+  (e.g. a policy revision entry) previously failed the whole document with
+  `ParseFailure`. Fixed upstream in the sc2in/zig-yaml fork (0.3.1, "comment
+  terminates a plain scalar"); this release bumps the pin and adds
+  front-matter regression tests.
+
 ### Added
 
 - **Opt-in TeX math** (`Parser{ .math = true }`; off by default). `$…$` parses

build.zig.zon

@@ -67,8 +67,8 @@
             .lazy = true,
         },
         .yaml = .{
-            .url = "git+https://github.com/sc2in/zig-yaml#691a2c37f1546fe843f7080fd7bf4450f1facb2e",
-            .hash = "zig_yaml-0.3.0-C1161oSpAgCiEJXrktVkXNSWNQifQ8NWvNB-20PqoFc3",
+            .url = "git+https://github.com/sc2in/zig-yaml#7c60d9cd6ae596c8247ac74b5b8e32c329e7c1d0",
+            .hash = "zig_yaml-0.3.1-C1161s2zAgBOYGjCQB3uWdAadPevfdNiTaffefbhAhBq",
         },
     },
     // Specifies the set of files and directories that are included in this package.

build.zig.zon2json-lock

@@ -39,9 +39,9 @@
     "url": "git+https://github.com/mnemnion/mvzr?ref=v0.3.10#dd0e1bd2d6b10f9650317b30baef7ab7bc9dd9ec",
     "hash": "sha256-hUGdJPjC1PAm6zWL9eAE7A+wAfzf6Q7uSutT2Xe7EMU="
   },
-  "zig_yaml-0.3.0-C1161oSpAgCiEJXrktVkXNSWNQifQ8NWvNB-20PqoFc3": {
+  "zig_yaml-0.3.1-C1161s2zAgBOYGjCQB3uWdAadPevfdNiTaffefbhAhBq": {
     "name": "yaml",
-    "url": "git+https://github.com/sc2in/zig-yaml#691a2c37f1546fe843f7080fd7bf4450f1facb2e",
-    "hash": "sha256-8BNs41Ch8CmvRME13b6xXTD6VN2/2LewIsW7kp30tCY="
+    "url": "git+https://github.com/sc2in/zig-yaml#7c60d9cd6ae596c8247ac74b5b8e32c329e7c1d0",
+    "hash": "sha256-JAYq7B7gXd4+c60KXZ9b5IuaKLY7x7Bn9TNynyx4kog="
   }
 }

src/markdown/frontmatter_test.zig

@@ -978,3 +978,31 @@ test "frontmatter: parseFieldArg errors" {
     try tst.expectError(error.InvalidFieldArg, FrontMatter.parseFieldArg("no-equals-sign"));
     try tst.expectError(error.InvalidFieldArg, FrontMatter.parseFieldArg("=value-no-path"));
 }
+
+test "frontmatter: trailing comment on a block-sequence mapping line" {
+    // Regression: a trailing `# comment` after a plain scalar inside a block
+    // sequence (e.g. a policy revision entry) made the whole front matter
+    // fail with ParseFailure before zig-yaml 0.3.1.
+    const md =
+        "---\n" ++
+        "extra:\n" ++
+        "  major_revisions:\n" ++
+        "    - date: 2025-01-01  # when it happened\n" ++
+        "      version: \"1.0\"\n" ++
+        "---\n" ++
+        "Body.\n";
+    var fm = try FrontMatter.initFromMarkdown(tst.allocator, md);
+    defer fm.deinit();
+    const revs = fm.get("extra.major_revisions") orelse return error.Missing;
+    try tst.expectEqual(@as(usize, 1), revs.array.items.len);
+    const date = revs.array.items[0].object.get("date") orelse return error.Missing;
+    try tst.expectEqualStrings("2025-01-01", date.string);
+}
+
+test "frontmatter: trailing comment keeps top-level scalar intact" {
+    const md = "---\ntitle: My Policy  # a note\n---\nBody.\n";
+    var fm = try FrontMatter.initFromMarkdown(tst.allocator, md);
+    defer fm.deinit();
+    const t = fm.get("title") orelse return error.Missing;
+    try tst.expectEqualStrings("My Policy", t.string);
+}