show detailed error (#18229)

* show detailed error

* update

* update

* update

* update

Author: xiangyan99

sdk/core/azure-core/azure/core/exceptions.py

@@ -107,6 +107,28 @@ class ODataV4Format(object):
 
     http://docs.oasis-open.org/odata/odata-json-format/v4.0/os/odata-json-format-v4.0-os.html#_Toc372793091
 
+    Example of JSON:
+
+    error: {
+        "code": "ValidationError",
+        "message": "One or more fields contain incorrect values: ",
+        "details": [
+            {
+                "code": "ValidationError",
+                "target": "representation",
+                "message": "Parsing error(s): String '' does not match regex pattern '^[^{}/ :]+(?: :\\\\d+)?$'.
+                Path 'host', line 1, position 297."
+            },
+            {
+                "code": "ValidationError",
+                "target": "representation",
+                "message": "Parsing error(s): The input OpenAPI file is not valid for the OpenAPI specificate
+                https: //github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md
+                (schema https://github.com/OAI/OpenAPI-Specification/blob/master/schemas/v2.0/schema.json)."
+            }
+        ]
+    }
+
     :param dict json_object: A Python dict representing a ODataV4 JSON
     :ivar str ~.code: Its value is a service-defined error code.
      This code serves as a sub-status for the HTTP error code specified in the response.
@@ -160,7 +182,11 @@ def error(self):
         return self
 
     def __str__(self):
-        return "({}) {}".format(self.code, self.message)
+        return "({}) {}\n{}".format(
+            self.code,
+            self.message,
+            self.message_details()
+        )
 
     def message_details(self):
         """Return a detailled string of the error.

sdk/core/azure-core/tests/test_exceptions.py

@@ -122,8 +122,8 @@ def test_deserialized_httpresponse_error_code(self):
         }
         response = _build_response(json.dumps(message).encode("utf-8"))
         error = FakeHttpResponse(response, FakeErrorOne())
-        assert error.message == "(FakeErrorOne) A fake error"
-        assert str(error.error) == "(FakeErrorOne) A fake error"
+        assert "(FakeErrorOne) A fake error" in error.message
+        assert "(FakeErrorOne) A fake error" in str(error.error)
         assert error.error.code == "FakeErrorOne"
         assert error.error.message == "A fake error"
         assert error.response is response
@@ -149,8 +149,8 @@ def test_deserialized_httpresponse_error_message(self):
         }
         response = _build_response(json.dumps(message).encode("utf-8"))
         error = FakeHttpResponse(response, FakeErrorTwo())
-        assert error.message == "(FakeErrorTwo) A different fake error"
-        assert str(error.error) == "(FakeErrorTwo) A different fake error"
+        assert "(FakeErrorTwo) A different fake error" in error.message
+        assert "(FakeErrorTwo) A different fake error" in str(error.error)
         assert error.error.code == "FakeErrorTwo"
         assert error.error.message == "A different fake error"
         assert error.response is response