ENH: tests: Add a little test for the FontDescriptor dataclass

This patch adds a little test for the FontDescriptor dataclass
to make codecov happy!

Author: PJBrs

tests/test_font.py

@@ -0,0 +1,27 @@
+"""Test font-related functionality."""
+
+
+from pypdf._font import FontDescriptor
+
+
+def test_font_descriptor():
+    font_res = {"/BaseFont": "/Helvetica"}
+    my_font = FontDescriptor.from_font_res(font_res)
+    assert my_font.family == "Helvetica"
+    assert my_font.weight == "Medium"
+    assert my_font.ascent == 718
+    assert my_font.descent == -207
+
+    test_string = "This is a long sentence. !@%%^€€€. çûįö¶´"
+    charwidth = sum(my_font.character_widths[char] for char in test_string)
+    assert charwidth == 19251
+
+    font_res = {"/BaseFont": "/Palatino"}
+    my_font = FontDescriptor.from_font_res(font_res)
+    assert my_font.weight == "Unknown"
+
+    font_res = {"/BaseFont": "/Courier-Bold"}
+    my_font = FontDescriptor.from_font_res(font_res)
+    assert my_font.italic_angle == 0
+    assert my_font.flags == 64
+    assert my_font.bbox == (-113.0, -250.0, 749.0, 801.0)