Address review comments

Author: pramodsatya

presto-native-sidecar-plugin/src/test/java/com/facebook/presto/sidecar/expressions/TestNativeExpressionOptimizer.java

@@ -86,11 +86,25 @@ public void tearDown()
     @Test
     public void testLambdaBodyConstantFolding()
     {
-        assertOptimizedEquals("transform(ARRAY[unbound_long, unbound_long2], x -> 1 + 1)",
+        // Simple lambda constant folding.
+        assertOptimizedEquals(
+                "transform(ARRAY[unbound_long, unbound_long2], x -> 1 + 1)",
                 "transform(ARRAY[unbound_long, unbound_long2], x -> 2)");
-        assertOptimizedEquals("transform(ARRAY[unbound_long, unbound_long2], x -> cast('123' AS integer))", "transform(ARRAY[unbound_long, unbound_long2], x -> 123)");
-        assertOptimizedEquals("transform(ARRAY[unbound_long, unbound_long2], x -> cast(json_parse('[1, 2]') AS ARRAY<INTEGER>)[1] + 1)",
+        assertOptimizedEquals(
+                "transform(ARRAY[unbound_long, unbound_long2], x -> cast('123' AS integer))",
+                "transform(ARRAY[unbound_long, unbound_long2], x -> 123)");
+        assertOptimizedEquals(
+                "transform(ARRAY[unbound_long, unbound_long2], x -> cast(json_parse('[1, 2]') AS ARRAY<INTEGER>)[1] + 1)",
                 "transform(ARRAY[unbound_long, unbound_long2], x -> 2)");
+
+        // Nested lambda constant folding.
+        assertOptimizedEquals(
+                "transform(ARRAY[unbound_long, unbound_long2], x -> transform(ARRAY[1, 2], y -> 1 + 1))",
+                "transform(ARRAY[unbound_long, unbound_long2], x -> transform(ARRAY[1, 2], y -> 2))");
+        // Multiple lambda occurrences constant folding.
+        assertOptimizedEquals(
+                "filter(transform(ARRAY[unbound_long, unbound_long2], x -> 1 + 1), x -> true and false)",
+                "filter(transform(ARRAY[unbound_long, unbound_long2], x -> 2), x -> false)");
     }
 
     private void assertOptimizedEquals(@Language("SQL") String actual, @Language("SQL") String expected)