Increase pivot table test coverage

Cover the previously-unexercised code paths flagged by Coveralls:
- writer: month and year date grouping, and a fractional numeric interval
  (the non-integer num() path);
- reader: reading an explicit dataField subtotal attribute back from a saved
  file;
- worksheet: the getPivotTables() alias, addPivotTable(), case-insensitive
  getPivotTableByName(), the no-match lookup, and removePivotTableCollection().

tests/PhpSpreadsheetTests/Worksheet/PivotTableBuilderTest.php

@@ -141,6 +141,70 @@ class PivotTableBuilderTest extends TestCase
         self::assertStringContainsString('<s v="Qtr4"/>', $cacheDefinition);
     }
 
+    public function testDateMonthGroupingIsEmitted(): void
+    {
+        $spreadsheet = $this->groupingSpreadsheet();
+        $builder = new PivotTableBuilder($spreadsheet->getSheetByNameOrThrow('Data'), 'A1:D5');
+        $builder
+            ->groupFieldByDate('OrderDate', PivotFieldGroup::GROUP_BY_MONTHS)
+            ->addRowField('OrderDate')
+            ->addDataField('Amount', PivotField::SUBTOTAL_SUM)
+            ->build($spreadsheet->getSheetByNameOrThrow('Pivot'), 'A3', 'ByMonth');
+
+        $outputFile = $this->save($spreadsheet);
+
+        $zip = new ZipArchive();
+        self::assertTrue($zip->open($outputFile) === true);
+        $cacheDefinition = (string) $zip->getFromName('xl/pivotCache/pivotCacheDefinition1.xml');
+        $zip->close();
+
+        self::assertStringContainsString('<rangePr groupBy="months"/>', $cacheDefinition);
+        self::assertStringContainsString('<s v="Jan"/>', $cacheDefinition);
+        self::assertStringContainsString('<s v="Dec"/>', $cacheDefinition);
+    }
+
+    public function testDateYearGroupingIsEmitted(): void
+    {
+        $spreadsheet = $this->groupingSpreadsheet();
+        $builder = new PivotTableBuilder($spreadsheet->getSheetByNameOrThrow('Data'), 'A1:D5');
+        $builder
+            ->groupFieldByDate('OrderDate', PivotFieldGroup::GROUP_BY_YEARS)
+            ->addRowField('OrderDate')
+            ->addDataField('Amount', PivotField::SUBTOTAL_SUM)
+            ->build($spreadsheet->getSheetByNameOrThrow('Pivot'), 'A3', 'ByYear');
+
+        $outputFile = $this->save($spreadsheet);
+
+        $zip = new ZipArchive();
+        self::assertTrue($zip->open($outputFile) === true);
+        $cacheDefinition = (string) $zip->getFromName('xl/pivotCache/pivotCacheDefinition1.xml');
+        $zip->close();
+
+        self::assertStringContainsString('<rangePr groupBy="years"/>', $cacheDefinition);
+    }
+
+    public function testNumericGroupingWithFractionalIntervalIsEmitted(): void
+    {
+        $spreadsheet = $this->groupingSpreadsheet();
+        $builder = new PivotTableBuilder($spreadsheet->getSheetByNameOrThrow('Data'), 'A1:D5');
+        $builder
+            ->groupFieldByNumericRange('Amount', 2.5, 0.0, 5.0)
+            ->addRowField('Amount')
+            ->addDataField('Amount', PivotField::SUBTOTAL_SUM)
+            ->build($spreadsheet->getSheetByNameOrThrow('Pivot'), 'A3', 'FractionGroups');
+
+        $outputFile = $this->save($spreadsheet);
+
+        $zip = new ZipArchive();
+        self::assertTrue($zip->open($outputFile) === true);
+        $cacheDefinition = (string) $zip->getFromName('xl/pivotCache/pivotCacheDefinition1.xml');
+        $zip->close();
+
+        // Fractional interval must keep its decimal (num() non-integer path).
+        self::assertStringContainsString('groupInterval="2.5"', $cacheDefinition);
+        self::assertStringContainsString('<s v="0-2.5"/>', $cacheDefinition);
+    }
+
     public function testGroupingRejectsUnknownField(): void
     {
         $spreadsheet = $this->groupingSpreadsheet();
@@ -273,6 +337,15 @@ class PivotTableBuilderTest extends TestCase
 
         self::assertStringContainsString('subtotal="average"', $definition);
         self::assertStringContainsString('name="Average of Amount"', $definition);
+
+        // Reading the file back must recover the explicit subtotal attribute.
+        $reloaded = (new XlsxReader())->load($outputFile);
+        $pivotTable = $reloaded->getSheetByNameOrThrow('Pivot')->getPivotTableByName('AvgPivot');
+        self::assertNotNull($pivotTable);
+        $dataFields = $pivotTable->getDataFields();
+        self::assertCount(1, $dataFields);
+        self::assertSame(PivotField::SUBTOTAL_AVERAGE, $dataFields[0]->getSubtotal());
+        $reloaded->disconnectWorksheets();
     }
 
     /**

tests/PhpSpreadsheetTests/Worksheet/PivotTableModelTest.php

@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\PivotTable\PivotCacheDefinition;
 use PhpOffice\PhpSpreadsheet\Worksheet\PivotTable\PivotField;
 use PhpOffice\PhpSpreadsheet\Worksheet\PivotTable\PivotFieldGroup;
@@ -82,6 +83,34 @@ class PivotTableModelTest extends TestCase
         self::assertSame('MyPivot', $pivotTable->__toString());
     }
 
+    public function testWorksheetPivotTableCollection(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $worksheet = $spreadsheet->getActiveSheet();
+
+        self::assertCount(0, $worksheet->getPivotTableCollection());
+        self::assertSame([], $worksheet->getPivotTableNames());
+        self::assertNull($worksheet->getPivotTableByName('Missing'));
+
+        $pivotTable = new PivotTable('First');
+        self::assertSame($worksheet, $worksheet->addPivotTable($pivotTable));
+
+        // addPivotTable attaches the worksheet to the pivot table.
+        self::assertSame($worksheet, $pivotTable->getWorksheet());
+
+        // getPivotTables() is an alias of getPivotTableCollection().
+        self::assertCount(1, $worksheet->getPivotTables());
+        self::assertSame(['First'], $worksheet->getPivotTableNames());
+        self::assertSame($pivotTable, $worksheet->getPivotTableByName('First'));
+        // Name lookup is case-insensitive.
+        self::assertSame($pivotTable, $worksheet->getPivotTableByName('FIRST'));
+
+        self::assertSame($worksheet, $worksheet->removePivotTableCollection());
+        self::assertCount(0, $worksheet->getPivotTableCollection());
+
+        $spreadsheet->disconnectWorksheets();
+    }
+
     public function testPivotFieldSetters(): void
     {
         $field = new PivotField(2, 'Amount');