[Python] Add test checking that the nowstream advances by itself

mihaibudiu · mihaibudiu · commit 1c346c2c5da9 · 2025-10-21T00:10:14.000Z
Signed-off-by: Mihai Budiu &lt;mbudiu@feldera.com&gt;
diff --git a/python/tests/platform/test_nowstream.py b/python/tests/platform/test_nowstream.py
@@ -0,0 +1,49 @@
+import unittest
+import time
+
+from feldera.pipeline_builder import PipelineBuilder
+from feldera.runtime_config import RuntimeConfig
+from feldera.testutils import unique_pipeline_name
+from tests import TEST_CLIENT
+from feldera.enums import PipelineStatus
+
+def get_result(pipeline) -> str:
+    result = list(pipeline.query("SELECT * FROM v;"))
+    assert len(result) == 1
+    return result[0]['x']
+
+class TestNowStream(unittest.TestCase):
+    def test_nowstream(self):
+        """
+        Test the now() function:
+        pipeline should produce outputs even if no new inputs are supplied.
+        """
+
+        pipeline_name = unique_pipeline_name("test_now")
+
+        sql = """
+        CREATE MATERIALIZED VIEW v AS SELECT NOW() as X;
+        """
+
+        pipeline = PipelineBuilder(
+            TEST_CLIENT,
+            pipeline_name,
+            sql=sql,
+            runtime_config=RuntimeConfig(
+                # 10 times per second
+                clock_resolution_usecs=100000
+            ),
+        ).create_or_replace()
+
+        pipeline.start()
+        assert pipeline.status() == PipelineStatus.RUNNING
+        time0 = get_result(pipeline)
+        time.sleep(1)
+        time1 = get_result(pipeline)
+        # Time has increased; this works on string time representations too
+        # due to the standard format, which looks like `2025-10-20T20:55:16.350`
+        assert time1 > time0
+        pipeline.stop(force=True)
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/sql-to-dbsp-compiler/SQL-compiler/src/main/java/org/dbsp/sqlCompiler/compiler/CompilerOptions.java b/sql-to-dbsp-compiler/SQL-compiler/src/main/java/org/dbsp/sqlCompiler/compiler/CompilerOptions.java
@@ -195,6 +195,10 @@ public static class IO implements IDiff<IO>, IValidate {
         @Parameter(names = "--jdbcSource",
                 description = "Connection string to a database that contains table metadata")
         public String metadataSource = "";
+        // This option is ignored; it is here just for backward compatibility, and it will be removed.
+        @Parameter(names = "--nowstream", hidden = true,
+                description = "Implement NOW as a stream (true) or as an internal operator (false)")
+        public boolean ignored = true;
         @Parameter(names = "--sqlnames", hidden = true,
                 description = "Use the table names as identifiers in the generated code")
         public boolean sqlNames = false;
