refactor: show error message

.changes/unreleased/optimization-20260507-101040.yaml

@@ -0,0 +1,6 @@
+kind: optimization
+body: Shows explicit API error message
+time: 2026-05-07T10:10:40.73557+03:00
+custom:
+    Author: v-alexmoraru
+    AuthorLink: https://github.com/v-alexmoraru

src/fabric_cli/core/fab_exceptions.py

@@ -8,13 +8,17 @@
 # Default error constants - avoids circular imports
 DEFAULT_ERROR_MESSAGE = "An error occurred while processing the operation"
 DEFAULT_ERROR_CODE = "UnknownError"
+NOT_SET = object()
 
 
 class FabricCLIError(Exception):
-    def __init__(self, message=None, status_code=None):
-        # Use default values if not provided
+    def __init__(self, message=None, status_code=NOT_SET):
+        # message: values like (None, "") fall back to the default.
+        # status_code: default is applied only when omitted entirely;
+        # an explicit None is preserved (e.g. fallback paths that have no code).
         message = message or DEFAULT_ERROR_MESSAGE
-        status_code = status_code or DEFAULT_ERROR_CODE
+        if status_code is NOT_SET:
+            status_code = DEFAULT_ERROR_CODE
 
         super().__init__(message)
         self.message = message.rstrip(".")
@@ -78,12 +82,23 @@ def __init__(self, response_text):
             related_resource (dict): Details about the main related resource, if available.
             request_id (str): The ID of the request associated with the error.
         """
-        response = self._parse_json_response(response_text)
-
-        message = response.get("message")
-        error_code = response.get("errorCode")
-        self.more_details: list[dict] = response.get("moreDetails", [])
-        self.request_id = response.get("requestId")
+        try:
+            response = json.loads(response_text)
+            if not isinstance(response, dict):
+                raise ValueError("Unexpected JSON shape")
+            message = (
+                response.get("message")
+                if response.get("message") is not None
+                else response_text
+            )
+            error_code = response.get("errorCode")
+            self.more_details: list[dict] = response.get("moreDetails", [])
+            self.request_id = response.get("requestId")
+        except (json.JSONDecodeError, TypeError, ValueError):
+            message = response_text
+            error_code = None
+            self.more_details = []
+            self.request_id = None
 
         super().__init__(message, error_code)
 
@@ -105,7 +120,10 @@ def formatted_message(self, verbose=False):
             else f"{base_message}\n<grey>{detailed_message}</grey>"
         )
 
-        return f"{final_message}\n<grey>∟ Request Id: {self.request_id}</grey>"
+        if self.request_id:
+            final_message += f"\n<grey>∟ Request Id: {self.request_id}</grey>"
+
+        return final_message
 
 
 class OnelakeAPIError(FabricCLIError):

tests/test_utils/test_fab_custom_exception.py

@@ -1,7 +1,9 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
-from fabric_cli.core.fab_exceptions import FabricCLIError
+import json
+
+from fabric_cli.core.fab_exceptions import FabricAPIError, FabricCLIError
 
 
 def test_custom_error_message():
@@ -17,3 +19,68 @@ def test_custom_error_message_without_period():
 def test_custom_error_formatted_message_with_status_code():
     error = FabricCLIError("An error occurred.", status_code=404)
     assert error.formatted_message() == "[404] An error occurred"
+
+
+def test_fabric_api_error_valid_json_with_request_id():
+    payload = json.dumps(
+        {
+            "errorCode": "ItemNotFound",
+            "message": "The requested item was not found.",
+            "requestId": "abc-123",
+            "moreDetails": [],
+        }
+    )
+    error = FabricAPIError(payload)
+
+    assert error.status_code == "ItemNotFound"
+    assert error.message == "The requested item was not found"
+    assert error.request_id == "abc-123"
+    assert error.more_details == []
+
+
+def test_fabric_api_error_valid_json_without_request_id():
+    payload = json.dumps(
+        {
+            "errorCode": "Unauthorized",
+            "message": "Access denied.",
+        }
+    )
+    error = FabricAPIError(payload)
+
+    assert error.status_code == "Unauthorized"
+    assert error.request_id is None
+    # formatted_message should not append a request-id line
+    assert "Request Id" not in error.formatted_message(verbose=True)
+
+
+def test_fabric_api_error_non_json_body_falls_back_to_raw_text():
+    raw = "Internal Server Error"
+    error = FabricAPIError(raw)
+
+    assert error.message == raw.rstrip(".")
+    assert error.status_code is None
+    assert error.request_id is None
+    assert error.more_details == []
+
+
+def test_fabric_api_error_non_dict_json_falls_back_to_raw_text():
+    for raw in ('"just a string"', "[1, 2, 3]", "42", "true"):
+        error = FabricAPIError(raw)
+        assert error.message == raw.rstrip(".")
+        assert error.status_code is None
+        assert error.request_id is None
+        assert error.more_details == []
+
+
+def test_fabric_api_error_formatted_message_non_json_no_request_id_line():
+    error = FabricAPIError("Gateway Timeout")
+    formatted = error.formatted_message(verbose=True)
+    assert "Request Id" not in formatted
+    assert "Gateway Timeout" in formatted
+
+
+def test_fabric_api_error_none_input_falls_back_to_default_message():
+    error = FabricAPIError(None)
+    assert error.status_code is None
+    assert error.request_id is None
+    assert error.more_details == []