Get message for exception in most cases, except when status 422 received

qiskit_transpiler_service/wrappers/base.py

@@ -180,18 +180,20 @@ def _raise_transpiler_error_and_log(msg: str):
 
 
 def _get_error_msg_from_response(exc: requests.exceptions.HTTPError):
-    resp = exc.response.json()
-    detail = resp.get("detail")
-    # Default message
-    msg = "Internal error."
-
-    if isinstance(detail, str):
-        msg = detail
-    elif isinstance(detail, list):
-        detail_input = detail[0]["input"]
-        detail_msg = detail[0]["msg"]
-
-        if detail_input and detail_msg:
-            msg = f"Wrong input '{detail_input}'. {detail_msg}"
-
+    if exc.response.status_code == HTTPStatus.UNPROCESSABLE_ENTITY.value:
+        resp = exc.response.json()
+        detail = resp.get("detail")
+        # Default message
+        msg = "Internal error."
+
+        if isinstance(detail, str):
+            msg = detail
+        elif isinstance(detail, list):
+            detail_input = detail[0]["input"]
+            detail_msg = detail[0]["msg"]
+
+            if detail_input and detail_msg:
+                msg = f"Wrong input '{detail_input}'. {detail_msg}"
+    else:
+        msg = f"Internal error: {str(exc)}"
     return msg

tests/test_transpiler_service.py

@@ -175,6 +175,26 @@ def test_transpile_non_valid_backend():
         )
 
 
+def test_wrong_url():
+    random_circ = random_circuit(5, depth=2, seed=42)
+    transpiler_service = TranspilerService(
+        backend_name="ibm_kyoto",
+        ai="false",
+        optimization_level=3,
+    )
+
+    transpiler_service.transpiler_service.url = "https://cloud-transpiler-experimental.quantum.ibm.com/INVALID"
+
+    try:
+        transpiler_service.run(random_circ)
+        pytest.fail("Error expected")
+    except Exception as e:
+        assert (
+            "Internal error: 404 Client Error: Not Found for url:" in
+            str(e)
+        )
+
+
 def test_transpile_exceed_circuit_size():
     circuit = EfficientSU2(120, entanglement="full", reps=5).decompose()
     transpiler_service = TranspilerService(