[Identity] Update AzureCliCredential executable search (#41806)

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

Author: pvaneck

sdk/identity/azure-identity/CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Bugs Fixed
 
 - Fixed an issue with `AzurePowerShellCredential` not working correctly for users still using older versions of PowerShell (e.g., Windows PowerShell 5.1) where `-AsPlainText` is not supported in the `ConvertFrom-SecureString` cmdlet.  ([#41675](https://github.com/Azure/azure-sdk-for-python/pull/41675))
+- Fixed an issue with `AzureCliCredential` being unable to find the correct `az` executable for certain Python versions on Windows. ([#41806](https://github.com/Azure/azure-sdk-for-python/pull/41806))
 
 ### Other Changes
 

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

@@ -234,7 +234,11 @@ def sanitize_output(output: str) -> str:
 
 def _run_command(command_args: List[str], timeout: int) -> str:
     # Ensure executable exists in PATH first. This avoids a subprocess call that would fail anyway.
-    az_path = shutil.which(EXECUTABLE_NAME)
+    if sys.platform.startswith("win"):
+        # On Windows, the expected executable is az.cmd, so we check for that first, falling back to 'az' in case.
+        az_path = shutil.which(EXECUTABLE_NAME + ".cmd") or shutil.which(EXECUTABLE_NAME)
+    else:
+        az_path = shutil.which(EXECUTABLE_NAME)
     if not az_path:
         raise CredentialUnavailableError(message=CLI_NOT_FOUND)
 

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

@@ -184,7 +184,11 @@ async def close(self) -> None:
 
 async def _run_command(command_args: List[str], timeout: int) -> str:
     # Ensure executable exists in PATH first. This avoids a subprocess call that would fail anyway.
-    az_path = shutil.which(EXECUTABLE_NAME)
+    if sys.platform.startswith("win"):
+        # On Windows, the expected executable is az.cmd, so we check for that first, falling back to 'az' in case.
+        az_path = shutil.which(EXECUTABLE_NAME + ".cmd") or shutil.which(EXECUTABLE_NAME)
+    else:
+        az_path = shutil.which(EXECUTABLE_NAME)
     if not az_path:
         raise CredentialUnavailableError(message=CLI_NOT_FOUND)