Fix cast from date to varchar

Fail if the resulting string does not fit in the
bounded length of the varchar type.

core/trino-main/src/main/java/io/trino/type/DateOperators.java

@@ -15,6 +15,7 @@
 
 import io.airlift.slice.Slice;
 import io.trino.spi.TrinoException;
+import io.trino.spi.function.LiteralParameter;
 import io.trino.spi.function.LiteralParameters;
 import io.trino.spi.function.ScalarFunction;
 import io.trino.spi.function.ScalarOperator;
@@ -27,6 +28,7 @@
 import static io.trino.spi.function.OperatorType.CAST;
 import static io.trino.util.DateTimeUtils.parseDate;
 import static io.trino.util.DateTimeUtils.printDate;
+import static java.lang.String.format;
 
 public final class DateOperators
 {
@@ -35,9 +37,15 @@ private DateOperators() {}
     @ScalarOperator(CAST)
     @LiteralParameters("x")
     @SqlType("varchar(x)")
-    public static Slice castToSlice(@SqlType(StandardTypes.DATE) long value)
+    public static Slice castToSlice(@LiteralParameter("x") long x, @SqlType(StandardTypes.DATE) long value)
     {
-        return utf8Slice(printDate((int) value));
+        String stringValue = printDate((int) value);
+        // String is all-ASCII, so String.length() here returns actual code points count
+        if (stringValue.length() <= x) {
+            return utf8Slice(stringValue);
+        }
+
+        throw new TrinoException(INVALID_CAST_ARGUMENT, format("Value %s cannot be represented as varchar(%s)", stringValue, x));
     }
 
     @ScalarFunction("date")

core/trino-main/src/test/java/io/trino/sql/TestExpressionInterpreter.java

@@ -839,9 +839,13 @@ public void testCastDateToBoundedVarchar()
         assertEvaluatedEquals("CAST(DATE '2013-02-02' AS varchar(10))", "'2013-02-02'");
         assertEvaluatedEquals("CAST(DATE '-2013-02-02' AS varchar(50))", "'-2013-02-02'");
 
-        // incorrect behavior: the result value does not fit in the type
-        assertEvaluatedEquals("CAST(DATE '2013-02-02' AS varchar(9))", "'2013-02-02'");
-        assertEvaluatedEquals("CAST(DATE '-2013-02-02' AS varchar(9))", "'-2013-02-02'");
+        // the result value does not fit in the type
+        assertTrinoExceptionThrownBy(() -> evaluate("CAST(DATE '2013-02-02' AS varchar(9))"))
+                .hasErrorCode(INVALID_CAST_ARGUMENT)
+                .hasMessage("Value 2013-02-02 cannot be represented as varchar(9)");
+        assertTrinoExceptionThrownBy(() -> evaluate("CAST(DATE '-2013-02-02' AS varchar(9))"))
+                .hasErrorCode(INVALID_CAST_ARGUMENT)
+                .hasMessage("Value -2013-02-02 cannot be represented as varchar(9)");
     }
 
     @Test

core/trino-main/src/test/java/io/trino/sql/planner/iterative/rule/TestSimplifyExpressions.java

@@ -44,7 +44,6 @@
 import static io.trino.sql.planner.TypeAnalyzer.createTestingTypeAnalyzer;
 import static io.trino.sql.planner.iterative.rule.SimplifyExpressions.rewrite;
 import static java.util.stream.Collectors.toList;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.testng.Assert.assertEquals;
 
 public class TestSimplifyExpressions
@@ -250,14 +249,9 @@ public void testCastDateToBoundedVarchar()
         assertSimplifies("CAST(DATE '2013-02-02' AS varchar(10))", "'2013-02-02'");
         assertSimplifies("CAST(DATE '2013-02-02' AS varchar(50))", "CAST('2013-02-02' AS varchar(50))");
 
-        // the cast operator returns a value that is too long for the expected type ('2013-02-02' for varchar(3))
-        // the LiteralEncoder detects the mismatch and fails
-        assertThatThrownBy(() -> simplify("CAST(DATE '2013-02-02' AS varchar(3))"))
-                .hasMessage("Value [2013-02-02] does not fit in type varchar(3)");
-
-        // the cast operator returns a value that is too long for the expected type ('2013-02-02' for varchar(3))
-        // the value is nested in a comparison expression, so the mismatch is not detected by the LiteralEncoder
-        assertSimplifies("CAST(DATE '2013-02-02' AS varchar(3)) = '2013-02-02'", "true");
+        // cast from date to varchar fails, so the expression is not modified
+        assertSimplifies("CAST(DATE '2013-02-02' AS varchar(3))", "CAST(DATE '2013-02-02' AS varchar(3))");
+        assertSimplifies("CAST(DATE '2013-02-02' AS varchar(3)) = '2013-02-02'", "CAST(DATE '2013-02-02' AS varchar(3)) = '2013-02-02'");
     }
 
     private static void assertSimplifies(String expression, String expected)

core/trino-main/src/test/java/io/trino/type/TestDateTimeOperators.java

@@ -272,9 +272,7 @@ public void testDateCastToVarchar()
         assertFunction("cast(DATE '13-2-2' AS varchar)", VARCHAR, "0013-02-02");
         assertFunction("cast(DATE '2013-02-02' AS varchar(50))", createVarcharType(50), "2013-02-02");
         assertFunction("cast(DATE '2013-02-02' AS varchar(10))", createVarcharType(10), "2013-02-02");
-
-        // cast operator returns a value that does not fit in the result type. this causes error in the LiteralEncoder
-        assertFunctionThrowsIncorrectly("cast(DATE '2013-02-02' AS varchar(9))", IllegalArgumentException.class, "Value .2013-02-02. does not fit in type varchar.9.");
+        assertInvalidCast("cast(DATE '2013-02-02' AS varchar(9))", "Value 2013-02-02 cannot be represented as varchar(9)");
     }
 
     private static SqlDate toDate(DateTime dateTime)