Add tests related to ENSIP-10 implementation:

- Test the new ``ens_encode_name()`` from the ``ens.utils`` module.
- Test the new ``ENS.parent()`` method to extract a parent from an ENS name.

Unrelated to ENSIP-10 but served as a helpful abstraction to better implement it:

- Test the new ``Contract.decodeABI()`` method from the

Author: fselmo

tests/ens/test_utils.py

@@ -1,10 +1,100 @@
+import pytest
+
+from eth_utils import (
+    to_bytes,
+)
 
 from ens.utils import (
+    ens_encode_name,
     init_web3,
 )
+from web3.exceptions import (
+    ValidationError,
+)
 
 
 def test_init_adds_middlewares():
     w3 = init_web3()
     middlewares = map(str, w3.manager.middleware_onion)
     assert 'stalecheck_middleware' in next(middlewares)
+
+
+@pytest.mark.parametrize(
+    'name,expected',
+    (
+        # test some allowed cases
+        ('tester.eth', b'\x06tester\x03eth\x00'),
+        (
+            'a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p',
+            b'\x01a\x01b\x01c\x01d\x01e\x01f\x01g\x01h\x01i\x01j\x01k\x01l\x01m\x01n\x01o\x01p\x00'
+        ),
+        ('1.2.3.4.5.6.7.8.9.10', b'\x011\x012\x013\x014\x015\x016\x017\x018\x019\x0210\x00'),
+        ('abc.123.def-456.eth', b'\x03abc\x03123\x07def-456\x03eth\x00'),
+        ('abc.123.def-456.eth', b'\x03abc\x03123\x07def-456\x03eth\x00'),
+        ('nhéééééé.eth', b'\x0enh\xc3\xa9\xc3\xa9\xc3\xa9\xc3\xa9\xc3\xa9\xc3\xa9\x03eth\x00'),
+        ('🌈rainbow.eth', b'\x0b\xf0\x9f\x8c\x88rainbow\x03eth\x00'),
+        ('🐔🐔.tk', b'\x08\xf0\x9f\x90\x94\xf0\x9f\x90\x94\x02tk\x00'),
+
+        # test that label length may be less than 64
+        (f"{'a' * 63}.b", b'?' + (b'a' * 63) + b'\x01b\x00'),
+        (f"a.{'b'* 63}", b'\x01a' + b'?' + (b'b' * 63) + b'\x00'),
+        (f"abc-123.{'b'* 63}", b'\x07abc-123' + b'?' + b'b' * 63 + b'\x00'),
+    )
+)
+def test_ens_encode_name(name, expected):
+    assert ens_encode_name(name) == expected
+
+
+@pytest.mark.parametrize(
+    'name,expected',
+    (
+        (
+            f"{'a' * 63}.{'b' * 63}.{'c' * 63}.{'d' * 63}.{'e' * 63}.{'f' * 63}.{'g' * 63}",
+            b''.join([b'?' + to_bytes(text=label) * 63 for label in 'abcdefg']) + b'\x00'
+        ),
+        (
+            f"{'a-1' * 21}.{'b-2' * 21}.{'c-3' * 21}.{'d-4' * 21}.{'e-5' * 21}.{'f-6' * 21}",
+            b''.join([
+                b'?' + to_bytes(text=label) * 21 for label in [
+                    'a-1', 'b-2', 'c-3', 'd-4', 'e-5', 'f-6',
+                ]
+            ]) + b'\x00'
+        ),
+    )
+)
+def test_ens_encode_name_validating_total_encoded_name_size(name, expected):
+    # This test is important because dns encoding technically limits the total encoded domain name
+    # size to 255. ENSIP-10 expects the name to be DNS encoded with one of the exceptions
+    # being that the total encoded size can be any length.
+    ens_encoded = ens_encode_name(name)
+    assert len(ens_encoded) > 255
+    assert ens_encoded == expected
+
+
+@pytest.mark.parametrize('empty_name', ('', '.'))
+def test_ens_encode_name_returns_single_zero_byte_for_empty_name(empty_name):
+    assert ens_encode_name(empty_name) == b'\00'
+
+
+@pytest.mark.parametrize(
+    'name,invalid_label_index',
+    (
+        ('a' * 64, 0),
+        (f"{'a' * 64}.b", 0),
+        (f"a.{'b-1' * 21}x", 1),
+        (f"{'a' * 64}.{'1' * 63}.{'b' * 63}", 0),
+        (f"{'a' * 63}.{'1' * 64}.{'b' * 63}", 1),
+        (f"{'a' * 63}.{'1' * 63}.{'b' * 64}", 2),
+    )
+)
+def test_ens_encode_name_raises_ValidationError_on_label_lengths_over_63(name, invalid_label_index):
+    with pytest.raises(ValidationError, match=f'Label at position {invalid_label_index} too long'):
+        ens_encode_name(name)
+
+
+def test_ens_encode_name_normalizes_name_before_encoding():
+    assert ens_encode_name('Öbb.at') == ens_encode_name('öbb.at')
+    assert ens_encode_name('nhÉéÉéÉé.eth') == ens_encode_name('nhéééééé.eth')
+    assert ens_encode_name('TESTER.eth') == ens_encode_name('tester.eth')
+    assert ens_encode_name('test\u200btest.com') == ens_encode_name('testtest.com')
+    assert ens_encode_name("O\u0308bb.at") == ens_encode_name("öbb.at")