Add tests for frontmatter

tests/unit/test_frontmatter.py

@@ -0,0 +1,93 @@
+import datetime
+import pytest
+import yaml
+from omicron.ssg.output.article import ArticleMeta
+from omicron.ssg.output.content import ContentError
+
+
+@pytest.fixture
+def valid_data():
+    return yaml.safe_load("""
+        section: posts
+        slug: hello
+        title: Hello
+        date: 2024-01-01
+        """)
+
+
+@pytest.fixture
+def full_data():
+    return yaml.safe_load("""
+        section: posts
+        slug: hello
+        title: Hello
+        date: 2024-01-01
+        updated: 2024-02-01
+        tags: [python, testing]
+        summary: A short summary.
+        draft: true
+        """)
+
+
+@pytest.mark.parametrize("key", ["section", "slug", "title", "date"])
+def test_from_dict_missing_required_key(valid_data, key):
+    del valid_data[key]
+
+    with pytest.raises(ContentError, match=f"must contain a {key} property"):
+        ArticleMeta.from_dict(valid_data)
+
+
+@pytest.mark.parametrize(
+    "key, value, expected_type",
+    [
+        ("section", 1, "string"),
+        ("slug", 1, "string"),
+        ("title", 1, "string"),
+        ("date", "2024-01-01", "date"),
+        ("updated", "2024-01-01", "date"),
+        ("tags", "python", "list of strings"),
+        ("tags", [1, "python"], "list of strings"),
+        ("summary", 1, "string"),
+        ("draft", "yes", "boolean"),
+    ],
+)
+def test_from_dict_wrong_type(valid_data, key, value, expected_type):
+    valid_data[key] = value
+
+    with pytest.raises(
+        ContentError, match=f"{key} frontmatter property must be a {expected_type}"
+    ):
+        ArticleMeta.from_dict(valid_data)
+
+
+def test_from_dict_unexpected_field(valid_data):
+    valid_data["bogus"] = "value"
+
+    with pytest.raises(ContentError, match="unexpected frontmatter field.*bogus"):
+        ArticleMeta.from_dict(valid_data)
+
+
+def test_from_dict_minimal(valid_data):
+    meta = ArticleMeta.from_dict(valid_data)
+
+    assert meta.section == "posts"
+    assert meta.slug == "hello"
+    assert meta.title == "Hello"
+    assert meta.date == datetime.date(2024, 1, 1)
+    assert meta.updated is None
+    assert meta.tags == set()
+    assert meta.summary is None
+    assert meta.draft is False
+
+
+def test_from_dict_full(full_data):
+    meta = ArticleMeta.from_dict(full_data)
+
+    assert meta.section == "posts"
+    assert meta.slug == "hello"
+    assert meta.title == "Hello"
+    assert meta.date == datetime.date(2024, 1, 1)
+    assert meta.updated == datetime.date(2024, 2, 1)
+    assert meta.tags == {"python", "testing"}
+    assert meta.summary == "A short summary."
+    assert meta.draft is True