[Identity] Update credential docstrings (#37207)

ClientAssertionCredential docstrings were updated to advertise the fact
that `cache_persistence_options` is supported.

Fixed a docstring type in DeviceCodeCredential.

Signed-off-by: Paul Van Eck <paulvaneck@microsoft.com>

sdk/identity/azure-identity/TOKEN_CACHING.md

@@ -92,7 +92,7 @@ The following table indicates the state of in-memory and persistent caching in e
 | `AzureDeveloperCliCredential`  | Not Supported                                                          | Not Supported                 |
 | `AzurePipelinesCredential`     | Supported                                                              | Not Supported                 |
 | `AzurePowershellCredential`    | Not Supported                                                          | Not Supported                 |
-| `ClientAssertionCredential`    | Supported                                                              | Not Supported                 |
+| `ClientAssertionCredential`    | Supported                                                              | Supported                     |
 | `CertificateCredential`        | Supported                                                              | Supported                     |
 | `ClientSecretCredential`       | Supported                                                              | Supported                     |
 | `DefaultAzureCredential`       | Supported if the target credential in the credential chain supports it | Not Supported                 |

sdk/identity/azure-identity/azure/identity/_credentials/client_assertion.py

@@ -24,6 +24,9 @@ class ClientAssertionCredential(GetTokenMixin):
     :keyword str authority: Authority of a Microsoft Entra endpoint, for example
         "login.microsoftonline.com", the authority for Azure Public Cloud (which is the default).
         :class:`~azure.identity.AzureAuthorityHosts` defines authorities for other clouds.
+    :keyword cache_persistence_options: configuration for persistent token caching. If unspecified, the credential
+        will cache tokens in memory.
+    :paramtype cache_persistence_options: ~azure.identity.TokenCachePersistenceOptions
     :keyword List[str] additionally_allowed_tenants: Specifies tenants in addition to the specified "tenant_id"
         for which the credential may acquire tokens. Add the wildcard value "*" to allow the credential to
         acquire tokens for any tenant the application can access.

sdk/identity/azure-identity/azure/identity/_credentials/device_code.py

@@ -23,7 +23,7 @@ class DeviceCodeCredential(InteractiveCredential):
     SSH session. If a web browser is available, :class:`~azure.identity.InteractiveBrowserCredential` is more
     convenient because it automatically opens a browser to the login page.
 
-    :keyword str client_id: Client ID of the Microsoft Entra application that users will sign into. It is recommended
+    :param str client_id: Client ID of the Microsoft Entra application that users will sign into. It is recommended
         that developers register their applications and assign appropriate roles. For more information,
         visit https://aka.ms/azsdk/identity/AppRegistrationAndRoleAssignment. If not specified, users will
         authenticate to an Azure development application, which is not recommended for production scenarios.

sdk/identity/azure-identity/azure/identity/aio/_credentials/client_assertion.py

@@ -24,6 +24,9 @@ class ClientAssertionCredential(AsyncContextManager, GetTokenMixin):
     :keyword str authority: Authority of a Microsoft Entra endpoint, for example
         "login.microsoftonline.com", the authority for Azure Public Cloud (which is the default).
         :class:`~azure.identity.AzureAuthorityHosts` defines authorities for other clouds.
+    :keyword cache_persistence_options: configuration for persistent token caching. If unspecified, the credential
+        will cache tokens in memory.
+    :paramtype cache_persistence_options: ~azure.identity.TokenCachePersistenceOptions
     :keyword List[str] additionally_allowed_tenants: Specifies tenants in addition to the specified "tenant_id"
         for which the credential may acquire tokens. Add the wildcard value "*" to allow the credential to
         acquire tokens for any tenant the application can access.

sdk/identity/azure-identity/tests/test_client_assertion_credential.py

@@ -3,8 +3,12 @@
 # Licensed under the MIT License.
 # ------------------------------------
 from typing import Callable
-from unittest.mock import MagicMock
-from azure.identity import ClientAssertionCredential, WorkloadIdentityCredential
+from unittest.mock import MagicMock, Mock, patch
+
+from azure.identity._internal.aad_client_base import JWT_BEARER_ASSERTION
+from azure.identity import ClientAssertionCredential, TokenCachePersistenceOptions
+
+from helpers import build_aad_response, mock_response
 
 
 def test_init_with_kwargs():
@@ -34,3 +38,46 @@ def test_context_manager():
         assert transport.__enter__.called
         assert not transport.__exit__.called
     assert transport.__exit__.called
+
+
+def test_token_cache_persistence():
+    """The credential should use a persistent cache if cache_persistence_options are configured."""
+
+    access_token = "foo"
+    tenant_id: str = "TENANT_ID"
+    client_id: str = "CLIENT_ID"
+    scope = "scope"
+    assertion = "ASSERTION_TOKEN"
+    func: Callable[[], str] = lambda: assertion
+
+    def send(request, **kwargs):
+        assert request.data["client_assertion"] == assertion
+        assert request.data["client_assertion_type"] == JWT_BEARER_ASSERTION
+        assert request.data["client_id"] == client_id
+        assert request.data["grant_type"] == "client_credentials"
+        assert request.data["scope"] == scope
+
+        return mock_response(json_payload=build_aad_response(access_token=access_token))
+
+    with patch("azure.identity._internal.aad_client_base._load_persistent_cache") as load_persistent_cache:
+        credential = ClientAssertionCredential(
+            tenant_id=tenant_id,
+            client_id=client_id,
+            func=func,
+            cache_persistence_options=TokenCachePersistenceOptions(),
+            transport=Mock(send=send),
+        )
+
+        assert load_persistent_cache.call_count == 0
+        assert credential._client._cache is None
+        assert credential._client._cae_cache is None
+
+        token = credential.get_token(scope)
+        assert token.token == access_token
+        assert load_persistent_cache.call_count == 1
+        assert credential._client._cache is not None
+        assert credential._client._cae_cache is None
+
+        token = credential.get_token(scope, enable_cae=True)
+        assert load_persistent_cache.call_count == 2
+        assert credential._client._cae_cache is not None

sdk/identity/azure-identity/tests/test_client_assertion_credential_async.py

@@ -3,11 +3,15 @@
 # Licensed under the MIT License.
 # ------------------------------------
 from typing import Callable
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, Mock, patch
 
 import pytest
+from azure.identity._internal.aad_client_base import JWT_BEARER_ASSERTION
+from azure.identity import TokenCachePersistenceOptions
 from azure.identity.aio import ClientAssertionCredential
 
+from helpers import build_aad_response, mock_response
+
 
 def test_init_with_kwargs():
     tenant_id: str = "TENANT_ID"
@@ -38,3 +42,47 @@ async def test_context_manager():
         assert not transport.__aexit__.called
 
     assert transport.__aexit__.called
+
+
+@pytest.mark.asyncio
+async def test_token_cache_persistence():
+    """The credential should use a persistent cache if cache_persistence_options are configured."""
+
+    access_token = "foo"
+    tenant_id: str = "TENANT_ID"
+    client_id: str = "CLIENT_ID"
+    scope = "scope"
+    assertion = "ASSERTION_TOKEN"
+    func: Callable[[], str] = lambda: assertion
+
+    async def send(request, **kwargs):
+        assert request.data["client_assertion"] == assertion
+        assert request.data["client_assertion_type"] == JWT_BEARER_ASSERTION
+        assert request.data["client_id"] == client_id
+        assert request.data["grant_type"] == "client_credentials"
+        assert request.data["scope"] == scope
+
+        return mock_response(json_payload=build_aad_response(access_token=access_token))
+
+    with patch("azure.identity._internal.aad_client_base._load_persistent_cache") as load_persistent_cache:
+        credential = ClientAssertionCredential(
+            tenant_id=tenant_id,
+            client_id=client_id,
+            func=func,
+            cache_persistence_options=TokenCachePersistenceOptions(),
+            transport=Mock(send=send),
+        )
+
+        assert load_persistent_cache.call_count == 0
+        assert credential._client._cache is None
+        assert credential._client._cae_cache is None
+
+        token = await credential.get_token(scope)
+        assert token.token == access_token
+        assert load_persistent_cache.call_count == 1
+        assert credential._client._cache is not None
+        assert credential._client._cae_cache is None
+
+        token = await credential.get_token(scope, enable_cae=True)
+        assert load_persistent_cache.call_count == 2
+        assert credential._client._cae_cache is not None