Don't crash on front matter with non-string mapping keys

frontmatter/__init__.py

@@ -191,7 +191,13 @@ def loads(
     text = u(text, encoding)
     handler = handler or detect_format(text, handlers)
     metadata, content = parse(text, encoding, handler, **defaults)
-    return Post(content, handler, **metadata)
+    # Assign the metadata dict directly rather than splatting it as keyword
+    # arguments: YAML/TOML mappings allow non-string keys (ints, booleans,
+    # dates), and Post(content, handler, **metadata) raises "keywords must be
+    # strings" on those, even though the front matter itself is valid.
+    post = Post(content, handler)
+    post.metadata = metadata
+    return post
 
 
 def dump(

tests/unit_test.py

@@ -61,6 +61,14 @@ def test_check_empty_frontmatter(self):
 
         self.assertEqual(ret, True)
 
+    def test_non_string_metadata_keys(self):
+        "YAML allows non-string mapping keys (e.g. ints); loads must not choke on them."
+        post = frontmatter.loads("---\n1: one\n2: two\n---\nbody")
+        self.assertEqual(post.metadata, {1: "one", 2: "two"})
+        self.assertEqual(post.content, "body")
+        # and the post still round-trips through dumps/loads
+        self.assertEqual(frontmatter.loads(frontmatter.dumps(post)).metadata, post.metadata)
+
     def test_no_frontmatter(self):
         "This is not a zen exercise."
         post = frontmatter.load("tests/empty/no-frontmatter.txt")