BAEL-7545: Fix DateTimeParseException (#18433)

Author: achraftt

core-java-modules/core-java-datetime-conversion-4/src/test/java/com/baeldung/datetimeparseexception/DateTimeParseExceptionUnitTest.java

@@ -0,0 +1,152 @@
+package com.baeldung.datetimeparseexception;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.*;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.TemporalAccessor;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class DateTimeParseExceptionUnitTest {
+
+    // Failing Test: Trying to obtain LocalDateTime from a date without time
+    @Test
+    void givenDateWithoutTime_whenParsedAsLocalDateTime_thenThrowsDateTimeParseException() {
+        String dateStr = "2024-03-25";
+        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE;
+        TemporalAccessor parsedDate = formatter.parse(dateStr);
+
+        DateTimeException exception = assertThrows(DateTimeException.class, () ->
+                LocalDateTime.from(parsedDate)
+        );
+
+        assertTrue(exception.getMessage().contains("Unable to obtain LocalDateTime from TemporalAccessor"));
+    }
+
+    // Fixed Version: Correctly using LocalDate
+    @Test
+    void givenDateWithoutTime_whenParsedAsLocalDate_thenSucceeds() {
+        String dateStr = "2024-03-25";
+        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE;
+        LocalDate date = LocalDate.parse(dateStr, formatter);
+
+        assertEquals(LocalDate.of(2024, 3, 25), date);
+    }
+
+    // Fixed Version: Correctly using LocalDateTime with default time
+    @Test
+    void givenDateWithTime_whenParsedAsLocalDateTime_thenSucceeds() {
+        String dateTimeStr = "2024-03-25T00:00:00";
+        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
+        LocalDateTime dateTime = LocalDateTime.parse(dateTimeStr, formatter);
+
+        assertEquals(LocalDateTime.of(2024, 3, 25, 0, 0, 0), dateTime);
+    }
+
+    // Failing Test: Trying to obtain LocalDateTime from DayOfWeek
+    @Test
+    void givenDayOfWeek_whenParsedAsLocalDateTime_thenThrowsDateTimeParseException() {
+        TemporalAccessor parsedDate = DayOfWeek.FRIDAY;
+
+        DateTimeException exception = assertThrows(DateTimeException.class, () ->
+                LocalDateTime.from(parsedDate)
+        );
+
+        assertTrue(exception.getMessage().contains("Unable to obtain LocalDateTime from TemporalAccessor"));
+    }
+
+    // Fixed Version: Correctly using DayOfWeek
+    @Test
+    void givenDayOfWeek_whenUsedAsIs_thenSucceeds() {
+        DayOfWeek day = DayOfWeek.FRIDAY;
+
+        assertEquals(DayOfWeek.FRIDAY, day);
+    }
+
+    // Fixed Version: Combine DayOfWeek with LocalDate and LocalTime
+    @Test
+    void givenDayOfWeek_whenCombinedWithLocalDateAndLocalTime_thenSucceeds() {
+        LocalDate date = LocalDate.of(2024, 3, 25); // Specific date
+        LocalTime time = LocalTime.of(14, 30);      // Set a specific time
+        LocalDateTime dateTime = LocalDateTime.of(date, time);
+
+        assertEquals(LocalDateTime.of(2024, 3, 25, 14, 30), dateTime);
+    }
+
+    // Failing Test: Trying to obtain LocalDateTime from LocalTime
+    @Test
+    void givenLocalTime_whenParsedAsLocalDateTime_thenThrowsDateTimeParseException() {
+        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_TIME;
+        TemporalAccessor parsedDate = formatter.parse("14:30:00");
+
+        DateTimeException exception = assertThrows(DateTimeException.class, () ->
+                LocalDateTime.from(parsedDate)
+        );
+
+        assertTrue(exception.getMessage().contains("Unable to obtain LocalDateTime from TemporalAccessor"));
+    }
+
+    // Fixed Version: Combine LocalTime with LocalDate to form a valid LocalDateTime
+    @Test
+    void givenLocalTime_whenCombinedWithLocalDate_thenSucceeds() {
+        LocalDate date = LocalDate.of(2024, 3, 25);
+        LocalTime time = LocalTime.parse("14:30:00");
+        LocalDateTime dateTime = LocalDateTime.of(date, time);
+
+        assertNotNull(dateTime);
+        assertEquals(LocalDateTime.of(2024, 3, 25, 14, 30), dateTime);
+    }
+
+    // Failing Test: Trying to obtain LocalDateTime from YearMonth
+    @Test
+    void givenYearMonth_whenParsedAsLocalDateTime_thenThrowsDateTimeParseException() {
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM");
+        TemporalAccessor parsedDate = formatter.parse("2024-03");
+
+        DateTimeException exception = assertThrows(DateTimeException.class, () ->
+                LocalDateTime.from(parsedDate)
+        );
+
+        assertTrue(exception.getMessage().contains("Unable to obtain LocalDateTime from TemporalAccessor"));
+    }
+
+    // Fixed Version: Correctly using YearMonth
+    @Test
+    void givenYearMonth_whenParsedCorrectly_thenSucceeds() {
+        YearMonth yearMonth = YearMonth.parse("2024-03", DateTimeFormatter.ofPattern("yyyy-MM"));
+        assertEquals(YearMonth.of(2024, 3), yearMonth);
+    }
+
+    // Failing Test: Trying to obtain LocalDateTime from MonthDay
+    @Test
+    void givenMonthDay_whenParsedAsLocalDateTime_thenThrowsDateTimeParseException() {
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MM-dd");
+        TemporalAccessor parsedDate = formatter.parse("03-25");
+
+        DateTimeException exception = assertThrows(DateTimeException.class, () ->
+                LocalDateTime.from(parsedDate)
+        );
+
+        assertTrue(exception.getMessage().contains("Unable to obtain LocalDateTime from TemporalAccessor"));
+    }
+
+    // Fixed Version: Correctly using MonthDay
+    @Test
+    void givenMonthDay_whenParsedCorrectly_thenSucceeds() {
+        MonthDay monthDay = MonthDay.parse("03-25", DateTimeFormatter.ofPattern("MM-dd"));
+        assertEquals(MonthDay.of(3, 25), monthDay);
+    }
+
+    // Fixed Version: Combine MonthDay with LocalDate and LocalTime
+    @Test
+    void givenMonthDay_whenCombinedWithYearAndTime_thenSucceeds() {
+        MonthDay monthDay = MonthDay.parse("03-25", DateTimeFormatter.ofPattern("MM-dd"));
+        LocalDate date = LocalDate.of(2024, monthDay.getMonth(), monthDay.getDayOfMonth());
+        LocalTime time = LocalTime.of(14, 30);
+        LocalDateTime dateTime = LocalDateTime.of(date, time);
+
+        assertNotNull(dateTime);
+        assertEquals(LocalDateTime.of(2024, 3, 25, 14, 30), dateTime);
+    }
+}