chore: Add in memory credential service (Experimental)

src/google/adk/auth/credential_service/in_memory_credential_service.py

@@ -0,0 +1,64 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from typing import Optional
+
+from typing_extensions import override
+
+from ...tools.tool_context import ToolContext
+from ...utils.feature_decorator import experimental
+from ..auth_credential import AuthCredential
+from ..auth_tool import AuthConfig
+from .base_credential_service import BaseCredentialService
+
+
+@experimental
+class InMemoryCredentialService(BaseCredentialService):
+  """Class for in memory implementation of credential service(Experimental)"""
+
+  def __init__(self):
+    super().__init__()
+    self._credentials = {}
+
+  @override
+  async def load_credential(
+      self,
+      auth_config: AuthConfig,
+      tool_context: ToolContext,
+  ) -> Optional[AuthCredential]:
+    credential_bucket = self._get_bucket_for_current_context(tool_context)
+    return credential_bucket.get(auth_config.credential_key)
+
+  @override
+  async def save_credential(
+      self,
+      auth_config: AuthConfig,
+      tool_context: ToolContext,
+  ) -> None:
+    credential_bucket = self._get_bucket_for_current_context(tool_context)
+    credential_bucket[auth_config.credential_key] = (
+        auth_config.exchanged_auth_credential
+    )
+
+  def _get_bucket_for_current_context(self, tool_context: ToolContext) -> str:
+    app_name = tool_context._invocation_context.app_name
+    user_id = tool_context._invocation_context.user_id
+
+    if app_name not in self._credentials:
+      self._credentials[app_name] = {}
+    if user_id not in self._credentials[app_name]:
+      self._credentials[app_name][user_id] = {}
+    return self._credentials[app_name][user_id]

tests/unittests/auth/credential_service/test_in_memory_credential_service.py

@@ -0,0 +1,323 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest.mock import Mock
+
+from fastapi.openapi.models import OAuth2
+from fastapi.openapi.models import OAuthFlowAuthorizationCode
+from fastapi.openapi.models import OAuthFlows
+from google.adk.auth.auth_credential import AuthCredential
+from google.adk.auth.auth_credential import AuthCredentialTypes
+from google.adk.auth.auth_credential import OAuth2Auth
+from google.adk.auth.auth_tool import AuthConfig
+from google.adk.auth.credential_service.in_memory_credential_service import InMemoryCredentialService
+from google.adk.tools.tool_context import ToolContext
+import pytest
+
+
+class TestInMemoryCredentialService:
+  """Tests for the InMemoryCredentialService class."""
+
+  @pytest.fixture
+  def credential_service(self):
+    """Create an InMemoryCredentialService instance for testing."""
+    return InMemoryCredentialService()
+
+  @pytest.fixture
+  def oauth2_auth_scheme(self):
+    """Create an OAuth2 auth scheme for testing."""
+    flows = OAuthFlows(
+        authorizationCode=OAuthFlowAuthorizationCode(
+            authorizationUrl="https://example.com/oauth2/authorize",
+            tokenUrl="https://example.com/oauth2/token",
+            scopes={"read": "Read access", "write": "Write access"},
+        )
+    )
+    return OAuth2(flows=flows)
+
+  @pytest.fixture
+  def oauth2_credentials(self):
+    """Create OAuth2 credentials for testing."""
+    return AuthCredential(
+        auth_type=AuthCredentialTypes.OAUTH2,
+        oauth2=OAuth2Auth(
+            client_id="mock_client_id",
+            client_secret="mock_client_secret",
+            redirect_uri="https://example.com/callback",
+        ),
+    )
+
+  @pytest.fixture
+  def auth_config(self, oauth2_auth_scheme, oauth2_credentials):
+    """Create an AuthConfig for testing."""
+    exchanged_credential = oauth2_credentials.model_copy(deep=True)
+    return AuthConfig(
+        auth_scheme=oauth2_auth_scheme,
+        raw_auth_credential=oauth2_credentials,
+        exchanged_auth_credential=exchanged_credential,
+    )
+
+  @pytest.fixture
+  def tool_context(self):
+    """Create a mock ToolContext for testing."""
+    mock_context = Mock(spec=ToolContext)
+    mock_invocation_context = Mock()
+    mock_invocation_context.app_name = "test_app"
+    mock_invocation_context.user_id = "test_user"
+    mock_context._invocation_context = mock_invocation_context
+    return mock_context
+
+  @pytest.fixture
+  def another_tool_context(self):
+    """Create another mock ToolContext with different app/user for testing isolation."""
+    mock_context = Mock(spec=ToolContext)
+    mock_invocation_context = Mock()
+    mock_invocation_context.app_name = "another_app"
+    mock_invocation_context.user_id = "another_user"
+    mock_context._invocation_context = mock_invocation_context
+    return mock_context
+
+  def test_init(self, credential_service):
+    """Test that the service initializes with an empty store."""
+    assert isinstance(credential_service._credentials, dict)
+    assert len(credential_service._credentials) == 0
+
+  @pytest.mark.asyncio
+  async def test_load_credential_not_found(
+      self, credential_service, auth_config, tool_context
+  ):
+    """Test loading a credential that doesn't exist returns None."""
+    result = await credential_service.load_credential(auth_config, tool_context)
+    assert result is None
+
+  @pytest.mark.asyncio
+  async def test_save_and_load_credential(
+      self, credential_service, auth_config, tool_context
+  ):
+    """Test saving and then loading a credential."""
+    # Save the credential
+    await credential_service.save_credential(auth_config, tool_context)
+
+    # Load the credential
+    result = await credential_service.load_credential(auth_config, tool_context)
+
+    # Verify the credential was saved and loaded correctly
+    assert result is not None
+    assert result == auth_config.exchanged_auth_credential
+    assert result.auth_type == AuthCredentialTypes.OAUTH2
+    assert result.oauth2.client_id == "mock_client_id"
+
+  @pytest.mark.asyncio
+  async def test_save_credential_updates_existing(
+      self, credential_service, auth_config, tool_context, oauth2_credentials
+  ):
+    """Test that saving a credential updates an existing one."""
+    # Save initial credential
+    await credential_service.save_credential(auth_config, tool_context)
+
+    # Create a new credential and update the auth_config
+    new_credential = AuthCredential(
+        auth_type=AuthCredentialTypes.OAUTH2,
+        oauth2=OAuth2Auth(
+            client_id="updated_client_id",
+            client_secret="updated_client_secret",
+            redirect_uri="https://updated.com/callback",
+        ),
+    )
+    auth_config.exchanged_auth_credential = new_credential
+
+    # Save the updated credential
+    await credential_service.save_credential(auth_config, tool_context)
+
+    # Load and verify the credential was updated
+    result = await credential_service.load_credential(auth_config, tool_context)
+    assert result is not None
+    assert result.oauth2.client_id == "updated_client_id"
+    assert result.oauth2.client_secret == "updated_client_secret"
+
+  @pytest.mark.asyncio
+  async def test_credentials_isolated_by_context(
+      self, credential_service, auth_config, tool_context, another_tool_context
+  ):
+    """Test that credentials are isolated between different app/user contexts."""
+    # Save credential in first context
+    await credential_service.save_credential(auth_config, tool_context)
+
+    # Try to load from another context
+    result = await credential_service.load_credential(
+        auth_config, another_tool_context
+    )
+    assert result is None
+
+    # Verify original context still has the credential
+    result = await credential_service.load_credential(auth_config, tool_context)
+    assert result is not None
+
+  @pytest.mark.asyncio
+  async def test_multiple_credentials_same_context(
+      self, credential_service, tool_context, oauth2_auth_scheme
+  ):
+    """Test storing multiple credentials in the same context with different keys."""
+    # Create two different auth configs with different credential keys
+    cred1 = AuthCredential(
+        auth_type=AuthCredentialTypes.OAUTH2,
+        oauth2=OAuth2Auth(
+            client_id="client1",
+            client_secret="secret1",
+            redirect_uri="https://example1.com/callback",
+        ),
+    )
+
+    cred2 = AuthCredential(
+        auth_type=AuthCredentialTypes.OAUTH2,
+        oauth2=OAuth2Auth(
+            client_id="client2",
+            client_secret="secret2",
+            redirect_uri="https://example2.com/callback",
+        ),
+    )
+
+    auth_config1 = AuthConfig(
+        auth_scheme=oauth2_auth_scheme,
+        raw_auth_credential=cred1,
+        exchanged_auth_credential=cred1,
+        credential_key="key1",
+    )
+
+    auth_config2 = AuthConfig(
+        auth_scheme=oauth2_auth_scheme,
+        raw_auth_credential=cred2,
+        exchanged_auth_credential=cred2,
+        credential_key="key2",
+    )
+
+    # Save both credentials
+    await credential_service.save_credential(auth_config1, tool_context)
+    await credential_service.save_credential(auth_config2, tool_context)
+
+    # Load and verify both credentials
+    result1 = await credential_service.load_credential(
+        auth_config1, tool_context
+    )
+    result2 = await credential_service.load_credential(
+        auth_config2, tool_context
+    )
+
+    assert result1 is not None
+    assert result2 is not None
+    assert result1.oauth2.client_id == "client1"
+    assert result2.oauth2.client_id == "client2"
+
+  def test_get_bucket_for_current_context_creates_nested_structure(
+      self, credential_service, tool_context
+  ):
+    """Test that _get_bucket_for_current_context creates the proper nested structure."""
+    storage = credential_service._get_bucket_for_current_context(tool_context)
+
+    # Verify the nested structure was created
+    assert "test_app" in credential_service._credentials
+    assert "test_user" in credential_service._credentials["test_app"]
+    assert isinstance(storage, dict)
+    assert storage is credential_service._credentials["test_app"]["test_user"]
+
+  def test_get_bucket_for_current_context_reuses_existing(
+      self, credential_service, tool_context
+  ):
+    """Test that _get_bucket_for_current_context reuses existing structure."""
+    # Create initial structure
+    storage1 = credential_service._get_bucket_for_current_context(tool_context)
+    storage1["test_key"] = "test_value"
+
+    # Get storage again
+    storage2 = credential_service._get_bucket_for_current_context(tool_context)
+
+    # Verify it's the same storage instance
+    assert storage1 is storage2
+    assert storage2["test_key"] == "test_value"
+
+  def test_get_storage_different_apps(
+      self, credential_service, tool_context, another_tool_context
+  ):
+    """Test that different apps get different storage instances."""
+    storage1 = credential_service._get_bucket_for_current_context(tool_context)
+    storage2 = credential_service._get_bucket_for_current_context(
+        another_tool_context
+    )
+
+    # Verify they are different storage instances
+    assert storage1 is not storage2
+
+    # Verify the structure
+    assert "test_app" in credential_service._credentials
+    assert "another_app" in credential_service._credentials
+    assert "test_user" in credential_service._credentials["test_app"]
+    assert "another_user" in credential_service._credentials["another_app"]
+
+  @pytest.mark.asyncio
+  async def test_same_user_different_apps(
+      self, credential_service, auth_config
+  ):
+    """Test that the same user in different apps get isolated storage."""
+    # Create two contexts with same user but different apps
+    context1 = Mock(spec=ToolContext)
+    mock_invocation_context1 = Mock()
+    mock_invocation_context1.app_name = "app1"
+    mock_invocation_context1.user_id = "same_user"
+    context1._invocation_context = mock_invocation_context1
+
+    context2 = Mock(spec=ToolContext)
+    mock_invocation_context2 = Mock()
+    mock_invocation_context2.app_name = "app2"
+    mock_invocation_context2.user_id = "same_user"
+    context2._invocation_context = mock_invocation_context2
+
+    # Save credential in app1
+    await credential_service.save_credential(auth_config, context1)
+
+    # Try to load from app2 (should not find it)
+    result = await credential_service.load_credential(auth_config, context2)
+    assert result is None
+
+    # Verify app1 still has the credential
+    result = await credential_service.load_credential(auth_config, context1)
+    assert result is not None
+
+  @pytest.mark.asyncio
+  async def test_same_app_different_users(
+      self, credential_service, auth_config
+  ):
+    """Test that different users in the same app get isolated storage."""
+    # Create two contexts with same app but different users
+    context1 = Mock(spec=ToolContext)
+    mock_invocation_context1 = Mock()
+    mock_invocation_context1.app_name = "same_app"
+    mock_invocation_context1.user_id = "user1"
+    context1._invocation_context = mock_invocation_context1
+
+    context2 = Mock(spec=ToolContext)
+    mock_invocation_context2 = Mock()
+    mock_invocation_context2.app_name = "same_app"
+    mock_invocation_context2.user_id = "user2"
+    context2._invocation_context = mock_invocation_context2
+
+    # Save credential for user1
+    await credential_service.save_credential(auth_config, context1)
+
+    # Try to load for user2 (should not find it)
+    result = await credential_service.load_credential(auth_config, context2)
+    assert result is None
+
+    # Verify user1 still has the credential
+    result = await credential_service.load_credential(auth_config, context1)
+    assert result is not None