code review + one more test

src/krux/qr.py

@@ -185,10 +185,9 @@ def max_qr_bytes(max_width):
     max_width -= 2  # Subtract frame width
     qr_version = (max_width - 17) // 4
     try:
-        capacity = QR_CAPACITY[qr_version - 1]
+        return QR_CAPACITY[qr_version - 1]
     except:
-        capacity = QR_CAPACITY[-1]
-    return capacity
+        return QR_CAPACITY[-1]
 
 
 def find_min_num_parts(data, max_width, qr_format):
@@ -217,9 +216,7 @@ def find_min_num_parts(data, max_width, qr_format):
         num_parts = (data_length + qr_capacity - 1) // qr_capacity
         # For UR, part size will be the input for "max_fragment_len"
         part_size = len(data.cbor) // num_parts
-        part_size = max(
-            part_size, UR_MIN_FRAGMENT_LENGTH
-        )
+        part_size = max(part_size, UR_MIN_FRAGMENT_LENGTH)
     else:
         raise ValueError("Invalid format type")
     return num_parts, part_size

tests/test_qr.py

@@ -135,7 +135,7 @@ def test_to_qr_codes(mocker, m5stickv, tdata):
     for case in cases:
         mocker.patch(
             "krux.display.lcd",
-            new=mocker.MagicMock(width=mocker.MagicMock(return_value=case[2]))
+            new=mocker.MagicMock(width=mocker.MagicMock(return_value=case[2])),
         )
         display = Display()
         qr_data_width = display.qr_data_width()
@@ -154,7 +154,7 @@ def test_to_qr_codes(mocker, m5stickv, tdata):
                 if i == total - 1:
                     break
             except Exception as e:
-                print("Error:",e)
+                print("Error:", e)
                 break
             i += 1
         assert len(codes) == expected_parts
@@ -168,3 +168,13 @@ def test_detect_plaintext_qr(mocker, m5stickv):
     )
 
     detect_format(PLAINTEXT_QR_DATA)
+
+
+def test_find_min_num_parts(m5stickv):
+    from krux.qr import find_min_num_parts
+
+    with pytest.raises(ValueError) as raised_ex:
+        find_min_num_parts("", 10, "format unknown")
+
+    assert raised_ex.type is ValueError
+    assert raised_ex.value.args[0] == "Invalid format type"