Regression on partition projection since version 477

[lucastheo]

Trino version

477

Please describe the bug

Date partition projection using only year-month formats (e.g., yyyy-MM) stopped working in Trino 477.

I utilize partition_projection_format=yyyy-MM to query an external table with year-month partitioning. Although this configuration operated correctly in Trino 476, it became non-functional in version 477.

This is a regression introduced by commit d1ca4558e9d ("Refactor DateProjection to use DateTimeFormatter"), which replaced SimpleDateFormat with DateTimeFormatter but did not account for formats that don't include a day component.

Error message returned when executing a SELECT query on this table:

SQL Error [65536]: Query failed (#20260408_171023_00000_7eebf): Unable to obtain LocalDateTime from TemporalAccessor: {MonthOfYear=1, Year=2021},ISO of type java.time.format.Parsed

Configuration:

CREATE TABLE hive.test_schema.test_table (
   test varchar COMMENT '',
   date varchar COMMENT 'Date partition formatted as YYYY-MM' WITH (partition_projection_format = 'yyyy-MM', partition_projection_interval = 28, partition_projection_interval_unit = 'DAYS', partition_projection_range = ARRAY['1970-01','NOW'], partition_projection_type = 'DATE')
)
COMMENT ''
WITH (
   external_location = '',
   format = 'PARQUET',
   partition_projection_enabled = true,
   partitioned_by = ARRAY['date']
)

Steps to Reproduce:
Add this test in io.trino.plugin.hive.projection.TestDateProjectionFactory. The functionality was successful in version 476, but experienced a failure in version 477.

   @Test
    void testYearMonthFormat()
    {
        Projection projection = new DateProjection("date", VARCHAR, ImmutableMap.<String, Object>builder()
                .put(COLUMN_PROJECTION_FORMAT, "yyyy-MM")
                .put(COLUMN_PROJECTION_RANGE, ImmutableList.of("2020-01", "2020-03"))
                .put(COLUMN_PROJECTION_INTERVAL, 1)
                .put(COLUMN_PROJECTION_INTERVAL_UNIT, ChronoUnit.DAYS)
                .buildOrThrow());
        assertThat(projection.getProjectedValues(Optional.empty())).contains("2020-01", "2020-02", "2020-03");
    }

Was the removal of this functionality intentional? Is it something the community wants to restore? If the community wants it and no one is working on it, I offer to implement it. I can draft a proposal or a PR for review.

Related Issues: #27233

[wendigo]

cc @chenjian2664