fix(fonts): group compound weight and style variants by family

tests/test_font_routes.py

@@ -1,3 +1,8 @@
+import pytest
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+import routes.font_routes as font_routes
 from routes.font_routes import _derive_family
 
 
@@ -9,3 +14,37 @@ def test_derive_family_splits_common_family_suffixes():
     assert _derive_family("FiraCode-SemiBold.ttf") == "Fira Code"
     assert _derive_family("NotoSans-Bold.otf") == "Noto Sans"
     assert _derive_family("RobotoSlab-Bold.woff2") == "Roboto Slab"
+
+
+@pytest.mark.parametrize("filename,expected", [
+    ("JetBrainsMono-SemiBoldItalic.woff2", "JetBrains Mono"),
+    ("FiraCode-BoldItalic.ttf", "Fira Code"),
+    ("NotoSans-ExtraLightItalic.otf", "Noto Sans"),
+    ("RobotoSlab-UltraBoldOblique.WOFF2", "Roboto Slab"),
+    ("SourceSansPro-Bold-Italic.woff", "Source Sans Pro"),
+    ("FiraCode-SemiBold_Italic.ttf", "Fira Code"),
+    ("FiraCode-Italic.woff2", "Fira Code"),
+    ("FiraCode-VF.woff2", "Fira Code"),
+    ("MyFont-Book.woff2", "My Font Book"),
+])
+def test_compound_weight_and_style_are_not_part_of_the_family(filename, expected):
+    assert _derive_family(filename) == expected
+
+
+def test_custom_font_endpoint_groups_all_styles_under_one_family(tmp_path, monkeypatch):
+    files = ["JetBrainsMono-Regular.woff2", "JetBrainsMono-SemiBoldItalic.woff2",
+             "JetBrainsMono-Bold-Oblique.ttf"]
+    for name in [*files, "OtherFont-Regular.otf", "README.md"]:
+        (tmp_path / name).write_bytes(b"filename-only discovery fixture")
+    monkeypatch.setattr(font_routes, "CUSTOM_FONTS_DIR", str(tmp_path))
+    app = FastAPI()
+    app.include_router(font_routes.setup_font_routes())
+    with TestClient(app) as client:
+        response = client.get("/api/fonts/custom")
+    assert response.status_code == 200
+    fonts = response.json()["fonts"]
+    assert set(fonts) == {"JetBrains Mono", "Other Font"}
+    assert fonts["JetBrains Mono"] == [
+        {"file": name, "url": f"/static/fonts/custom/{name}", "format": name.rsplit(".", 1)[1]}
+        for name in sorted(files)
+    ]