tests: Add tests of common module

Introduces unit tests for Solaar.

Related #1097

tests/logitech_receiver/test_common.py

@@ -0,0 +1,83 @@
+import pytest
+
+from lib.logitech_receiver import common
+
+
+def test_crc16():
+    value = b'123456789'
+    expected = 0x29B1
+
+    result = common.crc16(value)
+
+    assert result == expected
+
+
+def test_named_int():
+    named_int = common.NamedInt(0x2, 'pulse')
+
+    assert named_int.name == 'pulse'
+    assert named_int == 2
+
+
+def test_named_int_comparison():
+    default_value = 0
+    default_name = 'entry'
+    named_int = common.NamedInt(default_value, default_name)
+
+    named_int_equal = common.NamedInt(default_value, default_name)
+    named_int_unequal_name = common.NamedInt(default_value, 'unequal')
+    named_int_unequal_value = common.NamedInt(5, default_name)
+    named_int_unequal = common.NamedInt(2, 'unequal')
+
+    assert named_int == named_int_equal
+    assert named_int != named_int_unequal_name
+    assert named_int != named_int_unequal_value
+    assert named_int != named_int_unequal
+
+
+@pytest.fixture
+def named_ints():
+    return common.NamedInts(empty=0, critical=5, low=20, good=50, full=90)
+
+
+def test_named_ints(named_ints):
+    assert named_ints.empty == 0
+    assert named_ints.empty.name == 'empty'
+    assert named_ints.critical == 5
+    assert named_ints.critical.name == 'critical'
+    assert named_ints.low == 20
+    assert named_ints.low.name == 'low'
+    assert named_ints.good == 50
+    assert named_ints.good.name == 'good'
+    assert named_ints.full == 90
+    assert named_ints.full.name == 'full'
+
+    assert len(named_ints) == 5
+
+
+@pytest.mark.parametrize('bytes_input, expected_output', [
+    (b'\x01\x02\x03\x04', '01020304'),
+    (b'', ''),
+])
+def test_strhex(bytes_input, expected_output):
+    result = common.strhex(bytes_input)
+
+    assert result == expected_output
+
+
+def test_bytest2int():
+    value = b'\x12\x34\x56\x78'
+    expected = 0x12345678
+
+    result = common.bytes2int(value)
+
+    assert result == expected
+
+
+def test_int2bytes():
+    value = 0x12345678
+    expected = b'\x12\x34\x56\x78'
+
+    result = common.int2bytes(value)
+
+    assert result == expected