Add test for udf script output

pyproject.toml

@@ -87,6 +87,7 @@ markers = [
     "configuration: tests related to pyexasol settings and configuration.",
     "edge_cases: tests related to pyexasol and exasol edge cases scenarios.",
     "tls: tests related to tls.",
+    "udf: tests related to user defined functions.",
     "misc: miscellaneous tests which did not fit in the other categories."
 ]
 

test/integration/udf_test.py

@@ -0,0 +1,78 @@
+import pytest
+import pyexasol
+from inspect import cleandoc
+
+
+@pytest.fixture
+def logging_address():
+    # 172.17.0.1 is an IP address of docker host in Linux
+    yield ("172.17.0.1", 8580)
+
+
+@pytest.fixture
+def connection(dsn, user, password, schema, logging_address):
+    _, port = logging_address
+    con = pyexasol.connect(
+        dsn=dsn,
+        user=user,
+        password=password,
+        schema=schema,
+        udf_output_bind_address=("", port),
+        udf_output_connect_address=logging_address,
+    )
+
+    yield con
+
+    con.close()
+
+
+@pytest.fixture
+def echo(connection, logging_address):
+    name = "ECHO"
+    ip, port = logging_address
+    udf = cleandoc(
+        f"""
+        --/
+        CREATE OR REPLACE LUA SCALAR SCRIPT {name}(text VARCHAR(2000))
+            RETURNS VARCHAR(2000) AS
+
+        function run(ctx)
+            local socket = require("socket")
+            local tcp_socket = socket.tcp()
+            local ok, err = tcp_socket:connect("{ip}", {port})
+            tcp_socket:send(ctx.text)
+            tcp_socket:shutdown()
+            return ctx.text
+        end
+        /
+        """
+    )
+    connection.execute(udf)
+
+    def executor(text):
+        udf_call = f"SELECT {name}('{text}');"
+        stmt, logfiles = connection.execute_udf_output(udf_call)
+        result = stmt.fetchval()
+        log = "LOG: " + "".join((log.read_text() for log in logfiles))
+        return result, log
+
+    yield executor
+
+    drop = f"DROP SCRIPT IF EXISTS {name};"
+    connection.execute(drop)
+
+
+@pytest.mark.udf
+def test_udf_output(connection, echo):
+    text = "Some text which should be echoed"
+
+    result, log = echo(text)
+
+    expected_result = text
+    expected_log = f"LOG: {text}"
+
+    actual_result = result
+    actual_log = log
+
+    assert actual_result == expected_result
+    assert actual_log == expected_log