Fix Issue 1441 (isDateTime and Formulas) (#1480)

* Fix Issue 1441 (isDateTime and Formulas)

When you have a date-field which is a formula, isDateTime returns false.
https://github.com/PHPOffice/PhpSpreadsheet/issues/1441

Report makes sense; fixed as suggested. Also fixed a few minor
related issues, and added tests so that Shared/Date and Shared/TimeZone
are now completely covered.

Date/setDefaultTimeZone and TimeZone/setTimeZone were not consistent
about what to do in event of failure - return false or throw.
They will now both return false, which is what Date's function
said it would do in its doc block anyhow. Date/validateTimeZone will
continue to throw; it was protected, but was never called outside
Date, so I changed it to private.

TimeZone/getTimeZoneAdjustment checked for 'UST' when it probably
meant 'UTC', and, as it turns out, the check is not even needed.

The most serious problem was that TimeZone/validateTimeZone does not
check the backwards-compatible time zones. The timezone project
aggressively, and very controversially, "demotes" timezones;
such timezones eventually wind up in the PHP backwards-compatible list.
We want to make sure to check that list so that our applications do not
break when this happens.

src/PhpSpreadsheet/Shared/Date.php

@@ -4,10 +4,10 @@ namespace PhpOffice\PhpSpreadsheet\Shared;
 
 use DateTimeInterface;
 use DateTimeZone;
-use Exception;
 use PhpOffice\PhpSpreadsheet\Calculation\DateTime;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Cell\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 
 class Date
@@ -97,17 +97,18 @@ class Date
      * @param DateTimeZone|string $timeZone The timezone to set for all Excel datetimestamp to PHP DateTime Object conversions
      *
      * @return bool Success or failure
-     * @return bool Success or failure
      */
     public static function setDefaultTimezone($timeZone)
     {
-        if ($timeZone = self::validateTimeZone($timeZone)) {
+        try {
+            $timeZone = self::validateTimeZone($timeZone);
             self::$defaultTimeZone = $timeZone;
-
+            $retval = true;
-            return true;
+        } catch (PhpSpreadsheetException $e) {
+            $retval = false;
         }
 
-        return false;
+        return $retval;
     }
 
     /**
@@ -130,17 +131,17 @@ class Date
      * @param DateTimeZone|string $timeZone The timezone to validate, either as a timezone string or object
      *
      * @return DateTimeZone The timezone as a timezone object
-     * @return DateTimeZone The timezone as a timezone object
      */
-    protected static function validateTimeZone($timeZone)
+    private static function validateTimeZone($timeZone)
     {
-        if (is_object($timeZone) && $timeZone instanceof DateTimeZone) {
+        if ($timeZone instanceof DateTimeZone) {
             return $timeZone;
-        } elseif (is_string($timeZone)) {
+        }
+        if (in_array($timeZone, DateTimeZone::listIdentifiers(DateTimeZone::ALL_WITH_BC))) {
             return new DateTimeZone($timeZone);
         }
 
-        throw new Exception('Invalid timezone');
+        throw new PhpSpreadsheetException('Invalid timezone');
     }
 
     /**
@@ -316,7 +317,7 @@ class Date
      */
     public static function isDateTime(Cell $pCell)
     {
-        return is_numeric($pCell->getValue()) &&
+        return is_numeric($pCell->getCalculatedValue()) &&
             self::isDateTimeFormat(
                 $pCell->getWorksheet()->getStyle(
                     $pCell->getCoordinate()

src/PhpSpreadsheet/Shared/TimeZone.php

@@ -23,7 +23,7 @@ class TimeZone
      */
     private static function validateTimeZone($timezone)
     {
-        return in_array($timezone, DateTimeZone::listIdentifiers());
+        return in_array($timezone, DateTimeZone::listIdentifiers(DateTimeZone::ALL_WITH_BC));
     }
 
     /**
@@ -73,10 +73,6 @@ class TimeZone
             $timezone = self::$timezone;
         }
 
-        if ($timezone == 'UST') {
-            return 0;
-        }
-
         $objTimezone = new DateTimeZone($timezone);
         $transitions = $objTimezone->getTransitions($timestamp, $timestamp);
 

tests/PhpSpreadsheetTests/Shared/DateTest.php

@@ -3,10 +3,23 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use PHPUnit\Framework\TestCase;
 
 class DateTest extends TestCase
 {
+    private $dttimezone;
+
+    protected function setUp(): void
+    {
+        $this->dttimezone = Date::getDefaultTimeZone();
+    }
+
+    protected function tearDown(): void
+    {
+        Date::setDefaultTimeZone($this->dttimezone);
+    }
+
     public function testSetExcelCalendar(): void
     {
         $calendarValues = [
@@ -168,4 +181,41 @@ class DateTest extends TestCase
     {
         return require 'tests/data/Shared/Date/ExcelToTimestamp1900Timezone.php';
     }
+
+    public function testVarious(): void
+    {
+        Date::setDefaultTimeZone('UTC');
+        self::assertFalse(Date::stringToExcel('2019-02-29'));
+        self::assertTrue((bool) Date::stringToExcel('2019-02-28'));
+        self::assertTrue((bool) Date::stringToExcel('2019-02-28 11:18'));
+        self::assertFalse(Date::stringToExcel('2019-02-28 11:71'));
+        $date = Date::PHPToExcel('2020-01-01');
+        self::assertEquals(43831.0, $date);
+        $spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->setCellValue('B1', 'x');
+        $val = $sheet->getCell('B1')->getValue();
+        self::assertFalse(Date::timestampToExcel($val));
+        $cell = $sheet->getCell('A1');
+        self::assertNotNull($cell);
+        $cell->setValue($date);
+        $sheet->getStyle('A1')
+            ->getNumberFormat()
+            ->setFormatCode(NumberFormat::FORMAT_DATE_DATETIME);
+        self::assertTrue(null !== $cell && Date::isDateTime($cell));
+        $cella2 = $sheet->getCell('A2');
+        self::assertNotNull($cella2);
+        $cella2->setValue('=A1+2');
+        $sheet->getStyle('A2')
+            ->getNumberFormat()
+            ->setFormatCode(NumberFormat::FORMAT_DATE_DATETIME);
+        self::assertTrue(null !== $cella2 && Date::isDateTime($cella2));
+        $cella3 = $sheet->getCell('A3');
+        self::assertNotNull($cella3);
+        $cella3->setValue('=A1+4');
+        $sheet->getStyle('A3')
+            ->getNumberFormat()
+            ->setFormatCode('0.00E+00');
+        self::assertFalse(null !== $cella3 && Date::isDateTime($cella3));
+    }
 }

tests/PhpSpreadsheetTests/Shared/TimeZoneTest.php

@@ -2,11 +2,29 @@
 
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
+use DateTime;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Shared\TimeZone;
 use PHPUnit\Framework\TestCase;
 
 class TimeZoneTest extends TestCase
 {
+    private $tztimezone;
+
+    private $dttimezone;
+
+    protected function setUp(): void
+    {
+        $this->tztimezone = TimeZone::getTimeZone();
+        $this->dttimezone = Date::getDefaultTimeZone();
+    }
+
+    protected function tearDown(): void
+    {
+        TimeZone::setTimeZone($this->tztimezone);
+        Date::setDefaultTimeZone($this->dttimezone);
+    }
+
     public function testSetTimezone(): void
     {
         $timezoneValues = [
@@ -20,13 +38,51 @@ class TimeZoneTest extends TestCase
         foreach ($timezoneValues as $timezoneValue) {
             $result = TimeZone::setTimezone($timezoneValue);
             self::assertTrue($result);
+            $result = Date::setDefaultTimezone($timezoneValue);
+            self::assertTrue($result);
         }
     }
 
+    public function testSetTimezoneBackwardCompatible(): void
+    {
+        $bcTimezone = 'Etc/GMT+10';
+        $result = TimeZone::setTimezone($bcTimezone);
+        self::assertTrue($result);
+        $result = Date::setDefaultTimezone($bcTimezone);
+        self::assertTrue($result);
+    }
+
     public function testSetTimezoneWithInvalidValue(): void
     {
-        $unsupportedTimezone = 'Etc/GMT+10';
+        $unsupportedTimezone = 'XEtc/GMT+10';
         $result = TimeZone::setTimezone($unsupportedTimezone);
         self::assertFalse($result);
+        $result = Date::setDefaultTimezone($unsupportedTimezone);
+        self::assertFalse($result);
+    }
+
+    public function testTimeZoneAdjustmentsInvalidTz(): void
+    {
+        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
+        $dtobj = DateTime::createFromFormat('Y-m-d H:i:s', '2008-09-22 00:00:00');
+        $tstmp = $dtobj->getTimestamp();
+        $unsupportedTimeZone = 'XEtc/GMT+10';
+        TimeZone::getTimeZoneAdjustment($unsupportedTimeZone, $tstmp);
+    }
+
+    public function testTimeZoneAdjustments(): void
+    {
+        $dtobj = DateTime::createFromFormat('Y-m-d H:i:s', '2008-01-01 00:00:00');
+        $tstmp = $dtobj->getTimestamp();
+        $supportedTimeZone = 'UTC';
+        $adj = TimeZone::getTimeZoneAdjustment($supportedTimeZone, $tstmp);
+        self::assertEquals(0, $adj);
+        $supportedTimeZone = 'America/Toronto';
+        $adj = TimeZone::getTimeZoneAdjustment($supportedTimeZone, $tstmp);
+        self::assertEquals(-18000, $adj);
+        $supportedTimeZone = 'America/Chicago';
+        TimeZone::setTimeZone($supportedTimeZone);
+        $adj = TimeZone::getTimeZoneAdjustment(null, $tstmp);
+        self::assertEquals(-21600, $adj);
     }
 }

tests/data/Shared/Date/FormatCodes.php

@@ -146,4 +146,8 @@ return [
         false,
         '#,##0.00 "dollars"',
     ],
+    [
+        true,
+        '"date " y-m-d',
+    ],
 ];