feat: enhance to_py_decimal for improved decimal handling and add test for missing decimal class

Author: qevolg

taos-ws-py/src/common.rs

@@ -12,9 +12,9 @@ use taos::{taos_query::common::Timestamp, BorrowedValue, RawBlock};
 use crate::ConsumerException;
 
 pub fn to_py_decimal(value: impl std::fmt::Display, py: Python<'_>) -> PyResult<PyObject> {
-    let decimal = value.to_string();
     let decimal_mod = py.import("decimal")?;
     let decimal_cls = decimal_mod.getattr("Decimal")?;
+    let decimal = value.to_string();
     Ok(decimal_cls.call1((decimal,))?.into_py(py))
 }
 

taos-ws-py/src/lib.rs

@@ -280,7 +280,9 @@ impl TaosResult {
                             }
                             BorrowedValue::VarChar(s) => s.into_py(py),
                             BorrowedValue::NChar(v) => v.as_ref().into_py(py),
-                            BorrowedValue::Json(j) => std::str::from_utf8(&j).unwrap().into_py(py),
+                            BorrowedValue::Json(j) => std::str::from_utf8(&j)
+                                .map_err(|err| ProgrammingError::new_err(err.to_string()))?
+                                .into_py(py),
                             BorrowedValue::VarBinary(v) => v.as_ref().into_py(py),
                             BorrowedValue::Geometry(v) => v.as_ref().into_py(py),
                             BorrowedValue::Decimal64(v) => common::to_py_decimal(v, py)?,

taos-ws-py/tests/test_consumer.py

@@ -86,7 +86,7 @@ def test_report_connector_info():
     consumer2.subscribe(["test_topic_1"])
     time.sleep(2)
     res = conn.query("show connections")
-    assert sum(connector_info == col for row in res for col in row) >= 2
+    assert sum(connector_info == col for row in res for col in row) >= 3
     consumer2.unsubscribe()
 
     time.sleep(2)

taos-ws-py/tests/test_decimal.py

@@ -1,5 +1,6 @@
 import datetime
-import os
+import sys
+import types
 import pytest
 import taosws
 import time
@@ -158,3 +159,25 @@ def test_decimal_tmq():
         conn.execute("drop topic if exists topic_1775631845")
         conn.execute("drop database if exists test_1775631845")
         conn.close()
+
+
+@pytest.mark.skipif(utils.TEST_TD_3360, reason="skip for TD-3360")
+def test_decimal_fetch_reports_python_error_when_decimal_class_missing(monkeypatch):
+    conn = taosws.connect("ws://localhost:6041")
+    cursor = conn.cursor()
+    try:
+        cursor.execute("drop database if exists test_1775636199")
+        cursor.execute("create database test_1775636199")
+        cursor.execute("use test_1775636199")
+        cursor.execute("create table t0 (ts timestamp, c1 decimal(10, 2))")
+        cursor.execute("insert into t0 values(1752218982762, 99.9876)")
+
+        fake_decimal_module = types.ModuleType("decimal")
+        monkeypatch.setitem(sys.modules, "decimal", fake_decimal_module)
+
+        cursor.execute("select c1 from t0")
+        with pytest.raises(AttributeError, match=r"Decimal"):
+            cursor.fetchall()
+    finally:
+        cursor.execute("drop database if exists test_1775636199")
+        conn.close()