client: improvements to error handling and test_client script

client/zecale/commands/zecale

@@ -9,8 +9,10 @@ from zecale.commands.command_context import CommandContext
 from zecale.commands.zecale_register import register
 from zecale.commands.zecale_submit import submit
 from zecale.commands.zecale_get_batch import get_batch
+from grpc import RpcError
 from click import command, group, option, pass_context, Context, ClickException
 from click_default_group import DefaultGroup
+import sys
 
 
 @command()
@@ -26,7 +28,20 @@ def help(ctx: Context) -> None:
     raise ClickException("no command specified")
 
 
-@group(cls=DefaultGroup, default_if_no_args=True, default="help")
+class HandleRpcExceptions(DefaultGroup):
+    """
+    A click group which handles uncaught RpcExceptions with a sensible message
+    (similar to ClickException).
+    """
+    def __call__(self, *args, **kwargs):
+        try:
+            return DefaultGroup.__call__(self, *args, **kwargs)
+        except RpcError as ex:
+            print(f"error: {ex.details()}")
+            sys.exit(1)
+
+
+@group(cls=HandleRpcExceptions, default_if_no_args=True, default="help")
 @option(
     "--aggregator-server", "-a",
     default=AGGREGATOR_SERVER_ENDPOINT_DEFAULT,

scripts/test_client

@@ -26,15 +26,26 @@ zecale register --key vk.json --name ${APP_NAME} || echo Already registered
 ( zecale register --key vk.json --name ${APP_NAME} ) && \
     (echo Expected duplicate registration to fail; exit 1)
 
-# Send 4 transactions
+# Send 4 transactions (enough for 2 batches)
 
 zecale submit --name ${APP_NAME} --tx extproof1.json
 zecale submit --name ${APP_NAME} --tx extproof2.json
 zecale submit --name ${APP_NAME} --tx extproof3.json
 zecale submit --name ${APP_NAME} --tx extproof4.json
 
-# Request and aggregate proof
+# Request aggregate proofs. Assuming the server was empty at the beginning of
+# the test, the first two request should succeed, and the third should fail.
 
 zecale get-batch --name ${APP_NAME} --batch-file batch1.json
+zecale get-batch --name ${APP_NAME} --batch-file batch2.json
+zecale get-batch --name ${APP_NAME} --batch-file batch3.json && \
+    (echo Expected failure when no batch available; exit 1)
 
 popd # _test_client_data
+
+set +e
+set +x
+
+echo "=================================================="
+echo "==              Client Test Passed              =="
+echo "=================================================="