Make ModelRetry hashable (#3394)

Co-authored-by: Claude <[email protected]>
Co-authored-by: Douwe Maan <[email protected]>

Author: 3 people

pydantic_ai_slim/pydantic_ai/exceptions.py

@@ -44,6 +44,9 @@ def __init__(self, message: str):
     def __eq__(self, other: Any) -> bool:
         return isinstance(other, self.__class__) and other.message == self.message
 
+    def __hash__(self) -> int:
+        return hash((self.__class__, self.message))
+
     @classmethod
     def __get_pydantic_core_schema__(cls, _: Any, __: Any) -> core_schema.CoreSchema:
         """Pydantic core schema to allow `ModelRetry` to be (de)serialized."""

tests/test_exceptions.py

@@ -0,0 +1,58 @@
+"""Tests for exception classes."""
+
+from collections.abc import Callable
+from typing import Any
+
+import pytest
+
+from pydantic_ai import ModelRetry
+from pydantic_ai.exceptions import (
+    AgentRunError,
+    ApprovalRequired,
+    CallDeferred,
+    IncompleteToolCall,
+    ModelHTTPError,
+    UnexpectedModelBehavior,
+    UsageLimitExceeded,
+    UserError,
+)
+
+
+@pytest.mark.parametrize(
+    'exc_factory',
+    [
+        lambda: ModelRetry('test'),
+        lambda: CallDeferred(),
+        lambda: ApprovalRequired(),
+        lambda: UserError('test'),
+        lambda: AgentRunError('test'),
+        lambda: UnexpectedModelBehavior('test'),
+        lambda: UsageLimitExceeded('test'),
+        lambda: ModelHTTPError(500, 'model'),
+        lambda: IncompleteToolCall('test'),
+    ],
+    ids=[
+        'ModelRetry',
+        'CallDeferred',
+        'ApprovalRequired',
+        'UserError',
+        'AgentRunError',
+        'UnexpectedModelBehavior',
+        'UsageLimitExceeded',
+        'ModelHTTPError',
+        'IncompleteToolCall',
+    ],
+)
+def test_exceptions_hashable(exc_factory: Callable[[], Any]):
+    """Test that all exception classes are hashable and usable as keys."""
+    exc = exc_factory()
+
+    # Does not raise TypeError
+    _ = hash(exc)
+
+    # Can be used in sets and dicts
+    s = {exc}
+    d = {exc: 'value'}
+
+    assert exc in s
+    assert d[exc] == 'value'