Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/5988#discussion_r187577471
--- Diff:
flink-libraries/flink-table/src/test/scala/org/apache/flink/table/runtime/stream/sql/SqlITCase.scala
---
@@ -686,6 +686,28 @@ class SqlITCase extends StreamingWithStateTestBase {
assertEquals(List(expected.toString()),
StreamITCase.testResults.sorted)
}
+
+ @Test
+ def testNullableFunctionCall(): Unit = {
--- End diff --
We should test this more lightweight with a unit test instead of running a
complete query.
We can extend `ScalarFunctionsTest.testLPad()` with
```
testSqlApi(
"LPAD('hello', -1, 'x') IS NULL", "true"
)
```
to cover this case
---
