tests(nano): fix usage of raises with match

tests/nanocontracts/test_contract_upgrade.py

@@ -1,3 +1,5 @@
+import pytest
+
 from hathor.nanocontracts import Blueprint, Context, fallback, public
 from hathor.nanocontracts.exception import BlueprintDoesNotExist, NCFail, NCInvalidSyscall, NCMethodNotFound
 from hathor.nanocontracts.types import BlueprintId, ContractId, NCAction, NCArgs
@@ -127,7 +129,7 @@ def test_basic(self) -> None:
         assert isinstance(proxy_contract, ProxyBlueprint)
 
         self.runner.call_public_method(proxy_id, 'set_contract', ctx, proxy_id)
-        with self.assertRaises(NCInvalidSyscall, match='cannot call the same blueprint'):
+        with pytest.raises(NCInvalidSyscall, match='cannot call the same blueprint'):
             self.runner.call_public_method(proxy_id, 'inc', ctx)
 
         self.runner.call_public_method(proxy_id, 'set_contract', ctx, code1_id)
@@ -154,7 +156,7 @@ def test_basic(self) -> None:
         assert code2_contract.counter == 0
         assert proxy_contract.counter == 1
 
-        with self.assertRaises(NCFail):
+        with pytest.raises(NCFail):
             self.runner.call_public_method(proxy_id, 'upgrade', ctx, self.code3_bp_id, 'on_upgrade_fail')
         assert proxy_storage.get_blueprint_id() == self.proxy_bp_id
         assert proxy_contract.counter == 1
@@ -168,7 +170,7 @@ def test_basic(self) -> None:
         assert proxy_contract.counter == 3
 
         # it should invoke the fallback method which will fail calling `dec()` from code2's blueprint.
-        with self.assertRaises(NCMethodNotFound, match='method `dec` not found and no fallback is provided'):
+        with pytest.raises(NCMethodNotFound, match='method `dec` not found and no fallback is provided'):
             self.runner.call_public_method(proxy_id, 'dec', ctx)
         assert proxy_storage.get_blueprint_id() == self.proxy_bp_id
         assert proxy_contract.contract == code2_id
@@ -177,7 +179,7 @@ def test_basic(self) -> None:
         assert proxy_contract.counter == 3
 
         unknown_bp_id = self.gen_random_blueprint_id()
-        with self.assertRaises(BlueprintDoesNotExist):
+        with pytest.raises(BlueprintDoesNotExist):
             self.runner.call_public_method(proxy_id, 'upgrade_no_cb', ctx, unknown_bp_id)
 
         self.runner.call_public_method(proxy_id, 'upgrade', ctx, self.code3_bp_id, 'on_upgrade_inc')

tests/nanocontracts/test_rng.py

@@ -1,5 +1,7 @@
 from math import floor, sqrt
 
+import pytest
+
 from hathor.conf import HathorSettings
 from hathor.nanocontracts import Blueprint, Context, public
 from hathor.nanocontracts.catalog import NCBlueprintCatalog
@@ -71,41 +73,38 @@ def test_rng_override(self) -> None:
         seed = b'0' * 32
         rng = NanoRNG(seed=seed)
 
-        with self.assertRaises(AttributeError, match='Cannot assign methods to this object.'):
+        with pytest.raises(AttributeError, match='Cannot assign methods to this object.'):
             rng.random = lambda self: 2  # type: ignore[method-assign, misc, assignment]
 
-        with self.assertRaises(AttributeError, match='Cannot assign methods to this object.'):
+        with pytest.raises(AttributeError, match='Cannot assign methods to this object.'):
             setattr(rng, 'random', lambda self: 2)
 
-        with self.assertRaises(AttributeError, match='Cannot assign methods to this object.'):
+        with pytest.raises(AttributeError, match='Cannot assign methods to this object.'):
             from types import MethodType
             rng.random = MethodType(lambda self: 2, rng)  # type: ignore[method-assign]
 
-        with self.assertRaises(AttributeError, match='\'NanoRNG\' object attribute \'random\' is read-only'):
+        with pytest.raises(AttributeError, match='\'NanoRNG\' object attribute \'random\' is read-only'):
             object.__setattr__(rng, 'random', lambda self: 2)
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             NanoRNG.random = lambda self: 2  # type: ignore[method-assign]
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             setattr(NanoRNG, 'random', lambda self: 2)
 
-        with self.assertRaises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
+        with pytest.raises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
             object.__setattr__(NanoRNG, 'random', lambda self: 2)
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             rng.__class__.random = lambda self: 2  # type: ignore[method-assign]
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             setattr(rng.__class__, 'random', lambda self: 2)
 
-        with self.assertRaises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
+        with pytest.raises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
             object.__setattr__(rng.__class__, 'random', lambda self: 2)
 
-        # mypy incorrectly infers the type of `rng.random` as `Never` (leading to "Never not callable [misc]")
-        # due to the override attempts above, which are expected to fail at runtime but confuse static analysis.
-        # This is a false positive in the test context; use `reveal_type(rng.random)` to inspect the inferred type.
-        assert rng.random() < 1  # type: ignore[misc]
+        assert rng.random() < 1
 
     def test_rng_shell_class(self) -> None:
         seed = b'0' * 32
@@ -114,13 +113,13 @@ def test_rng_shell_class(self) -> None:
 
         assert rng1.__class__ != rng2.__class__
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             rng1.__class__.random = lambda self: 2  # type: ignore[method-assign]
 
-        with self.assertRaises(AttributeError, match='AttributeError: Cannot override method `random`'):
+        with pytest.raises(AttributeError, match='Cannot override method `random`'):
             setattr(rng1.__class__, 'random', lambda self: 2)
 
-        with self.assertRaises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
+        with pytest.raises(TypeError, match='can\'t apply this __setattr__ to NoMethodOverrideMeta object'):
             object.__setattr__(rng1.__class__, 'random', lambda self: 2)
 
     def assertGoodnessOfFitTest(self, observed: list[int], expected: list[int]) -> None: