diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index ea6a7b89..1ba11328 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -150,16 +150,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Calculation/Calculation.php
 
-		-
-			message: "#^Parameter \\#1 \\$str of function trim expects string, int\\|string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/Calculation.php
-
-		-
-			message: "#^Parameter \\#1 \\$str of function trim expects string, null given\\.$#"
-			count: 2
-			path: src/PhpSpreadsheet/Calculation/Calculation.php
-
 		-
 			message: "#^Parameter \\#2 \\$worksheet of static method PhpOffice\\\\PhpSpreadsheet\\\\DefinedName\\:\\:resolveName\\(\\) expects PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet, PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet\\|null given\\.$#"
 			count: 1
@@ -355,21 +345,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Calculation/Engineering/BesselK.php
 
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Calculation\\\\Engineering\\\\BitWise\\:\\:validateBitwiseArgument\\(\\) never returns int so it can be removed from the return type\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
-
-		-
-			message: "#^Parameter \\#1 \\$number of function floor expects float, float\\|int\\<0, 281474976710655\\>\\|string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
-
-		-
-			message: "#^Parameter \\#1 \\$number of function floor expects float, float\\|int\\|string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
-
 		-
 			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Calculation\\\\Engineering\\\\ConvertBase\\:\\:validatePlaces\\(\\) has parameter \\$places with no type specified\\.$#"
 			count: 1
@@ -820,16 +795,6 @@ parameters:
 			count: 3
 			path: src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
 
-		-
-			message: "#^Parameter \\#1 \\$low of function range expects float\\|int\\|string, string\\|null given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
-
-		-
-			message: "#^Parameter \\#2 \\$high of function range expects float\\|int\\|string, string\\|null given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
-
 		-
 			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Calculation\\\\LookupRef\\\\VLookup\\:\\:vlookupSort\\(\\) has no return type specified\\.$#"
 			count: 1
@@ -1220,16 +1185,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Cell/Coordinate.php
 
-		-
-			message: "#^Parameter \\#1 \\$input of function array_chunk expects array, array\\<int, string\\>\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Cell/Coordinate.php
-
-		-
-			message: "#^Parameter \\#2 \\$str of function explode expects string, array\\<int, string\\>\\|string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Cell/Coordinate.php
-
 		-
 			message: "#^Parameter \\#4 \\$currentRow of static method PhpOffice\\\\PhpSpreadsheet\\\\Cell\\\\Coordinate\\:\\:validateRange\\(\\) expects int, string given\\.$#"
 			count: 1
@@ -1910,11 +1865,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Helper/Html.php
 
-		-
-			message: "#^Parameter \\#1 \\$function of function call_user_func expects callable\\(\\)\\: mixed, array\\{\\$this\\(PhpOffice\\\\PhpSpreadsheet\\\\Helper\\\\Html\\), mixed\\} given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Helper/Html.php
-
 		-
 			message: "#^Parameter \\#1 \\$text of method PhpOffice\\\\PhpSpreadsheet\\\\RichText\\\\ITextElement\\:\\:setText\\(\\) expects string, string\\|null given\\.$#"
 			count: 1
@@ -2485,11 +2435,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Reader/Xls/MD5.php
 
-		-
-			message: "#^Parameter \\#1 \\$input of function array_values expects array, array\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Reader/Xls/MD5.php
-
 		-
 			message: "#^Property PhpOffice\\\\PhpSpreadsheet\\\\Reader\\\\Xls\\\\RC4\\:\\:\\$i has no type specified\\.$#"
 			count: 1
@@ -3300,71 +3245,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/Drawing.php
 
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\Drawing\\:\\:imagecreatefrombmp\\(\\) should return GdImage\\|resource but returns resource\\|false\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#1 \\$fp of function feof expects resource, resource\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#1 \\$fp of function fread expects resource, resource\\|false given\\.$#"
-			count: 2
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#1 \\$im of function imagecolorallocate expects resource, resource\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#1 \\$im of function imagesetpixel expects resource, resource\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#1 \\$x_size of function imagecreatetruecolor expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#2 \\$data of function unpack expects string, string\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#2 \\$red of function imagecolorallocate expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#2 \\$y_size of function imagecreatetruecolor expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#3 \\$green of function imagecolorallocate expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#3 \\$y of function imagesetpixel expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#4 \\$blue of function imagecolorallocate expects int, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
-		-
-			message: "#^Parameter \\#4 \\$col of function imagesetpixel expects int, int\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Drawing.php
-
 		-
 			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\Escher\\\\DgContainer\\:\\:getDgId\\(\\) has no return type specified\\.$#"
 			count: 1
@@ -3560,11 +3440,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/JAMA/Matrix.php
 
-		-
-			message: "#^Parameter \\#1 \\$str of function trim expects string, float\\|int given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/JAMA/Matrix.php
-
 		-
 			message: "#^Parameter \\#3 \\$c of method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\JAMA\\\\Matrix\\:\\:set\\(\\) expects float\\|int\\|null, string given\\.$#"
 			count: 2
@@ -3610,11 +3485,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/OLE.php
 
-		-
-			message: "#^Cannot use array destructuring on array\\|false\\.$#"
-			count: 3
-			path: src/PhpSpreadsheet/Shared/OLE.php
-
 		-
 			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\OLE\\:\\:getData\\(\\) should return string but returns string\\|false\\.$#"
 			count: 1
@@ -3640,11 +3510,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/OLE.php
 
-		-
-			message: "#^Parameter \\#2 \\$data of function unpack expects string, string\\|false given\\.$#"
-			count: 3
-			path: src/PhpSpreadsheet/Shared/OLE.php
-
 		-
 			message: "#^Parameter \\#2 \\$name of class PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\OLE\\\\PPS constructor expects string, null given\\.$#"
 			count: 1
@@ -3680,11 +3545,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/OLE.php
 
-		-
-			message: "#^Parameter \\#1 \\$var of function count expects array\\|Countable, string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/OLE/ChainedBlockStream.php
-
 		-
 			message: "#^Parameter \\#2 \\$offset of function array_slice expects int, float given\\.$#"
 			count: 1
@@ -4025,11 +3885,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
 
-		-
-			message: "#^Parameter \\#2 \\.\\.\\.\\$args of function array_merge expects array, float given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
-
 		-
 			message: "#^Call to an undefined method object\\:\\:getGoodnessOfFit\\(\\)\\.$#"
 			count: 1
@@ -4310,11 +4165,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php
 
-		-
-			message: "#^Parameter \\#2 \\$str of function explode expects string, string\\|null given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php
-
 		-
 			message: "#^Parameter \\#3 \\$subject of function preg_replace expects array\\|string, string\\|null given\\.$#"
 			count: 1
@@ -4435,11 +4285,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Worksheet/PageSetup.php
 
-		-
-			message: "#^Parameter \\#2 \\$str of function explode expects string, string\\|null given\\.$#"
-			count: 5
-			path: src/PhpSpreadsheet/Worksheet/PageSetup.php
-
 		-
 			message: "#^Property PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\PageSetup\\:\\:\\$pageOrder has no type specified\\.$#"
 			count: 1
@@ -4485,11 +4330,6 @@ parameters:
 			count: 4
 			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
 
-		-
-			message: "#^Cannot call method getValue\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\DefinedName\\|null\\.$#"
-			count: 2
-			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
-
 		-
 			message: "#^Cannot call method getWorksheet\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\DefinedName\\|null\\.$#"
 			count: 1
@@ -4530,11 +4370,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
 
-		-
-			message: "#^Parameter \\#1 \\$input of function array_splice expects array, ArrayObject\\<int, PhpOffice\\\\PhpSpreadsheet\\\\Chart\\\\Chart\\> given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
-
 		-
 			message: "#^Parameter \\#1 \\$range of static method PhpOffice\\\\PhpSpreadsheet\\\\Cell\\\\Coordinate\\:\\:rangeDimension\\(\\) expects string, string\\|false given\\.$#"
 			count: 1
@@ -4555,11 +4390,6 @@ parameters:
 			count: 2
 			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
 
-		-
-			message: "#^Parameter \\#2 \\$start of function substr expects int, int\\<0, max\\>\\|false given\\.$#"
-			count: 2
-			path: src/PhpSpreadsheet/Worksheet/Worksheet.php
-
 		-
 			message: "#^Parameter \\#3 \\$rotation of static method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\Font\\:\\:calculateColumnWidth\\(\\) expects int, int\\|null given\\.$#"
 			count: 1
@@ -4880,16 +4710,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Html.php
 
-		-
-			message: "#^Parameter \\#1 \\$im of function imagepng expects resource, GdImage\\|resource given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Html.php
-
-		-
-			message: "#^Parameter \\#1 \\$str of function base64_encode expects string, string\\|false given\\.$#"
-			count: 2
-			path: src/PhpSpreadsheet/Writer/Html.php
-
 		-
 			message: "#^Parameter \\#1 \\$string of function htmlspecialchars expects string, string\\|null given\\.$#"
 			count: 1
@@ -5015,16 +4835,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xls.php
 
-		-
-			message: "#^Parameter \\#1 \\$im of function imagepng expects resource, GdImage\\|resource given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls.php
-
-		-
-			message: "#^Parameter \\#1 \\$im of function imagepng expects resource, resource\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls.php
-
 		-
 			message: "#^Property PhpOffice\\\\PhpSpreadsheet\\\\Writer\\\\Xls\\:\\:\\$documentSummaryInformation \\(string\\) in isset\\(\\) is not nullable\\.$#"
 			count: 1
@@ -5205,11 +5015,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
 
-		-
-			message: "#^Parameter \\#1 \\$im of function imagecolorat expects resource, GdImage\\|resource given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
-
 		-
 			message: "#^Parameter \\#1 \\$string of function strlen expects string, string\\|false given\\.$#"
 			count: 1
@@ -5220,26 +5025,11 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
 
-		-
-			message: "#^Parameter \\#2 \\$col of function imagecolorsforindex expects int, int\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
-
-		-
-			message: "#^Parameter \\#2 \\$data of function unpack expects string, string\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
-
 		-
 			message: "#^Parameter \\#2 \\$length of function fread expects int\\<0, max\\>, int\\<0, max\\>\\|false given\\.$#"
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
 
-		-
-			message: "#^Parameter \\#2 \\$pieces of function implode expects array, array\\<int, string\\>\\|false given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xls/Worksheet.php
-
 		-
 			message: "#^Parameter \\#2 \\$subject of function preg_match expects string, string\\|null given\\.$#"
 			count: 2
@@ -5320,11 +5110,6 @@ parameters:
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xlsx.php
 
-		-
-			message: "#^Parameter \\#1 \\$function of function call_user_func expects callable\\(\\)\\: mixed, string given\\.$#"
-			count: 1
-			path: src/PhpSpreadsheet/Writer/Xlsx.php
-
 		-
 			message: "#^Parameter \\#1 \\$path of function basename expects string, array\\|string\\|null given\\.$#"
 			count: 1
@@ -5769,248 +5554,3 @@ parameters:
 			message: "#^Method PhpOffice\\\\PhpSpreadsheet\\\\Writer\\\\Xlsx\\\\Xlfn\\:\\:addXlfn\\(\\) should return string but returns string\\|null\\.$#"
 			count: 1
 			path: src/PhpSpreadsheet/Writer/Xlsx/Xlfn.php
-
-		-
-			message: "#^Unreachable statement \\- code above always terminates\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Calculation/Engine/RangeTest.php
-
-		-
-			message: "#^Call to static method PHPUnit\\\\Framework\\\\Assert\\:\\:assertSame\\(\\) with arguments PhpOffice\\\\PhpSpreadsheet\\\\Cell\\\\Cell, null and 'should get exact…' will always evaluate to false\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Collection/CellsTest.php
-
-		-
-			message: "#^Cannot call method getCoordinate\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Cell\\\\Cell\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Collection/CellsTest.php
-
-		-
-			message: "#^Cannot call method getParent\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Cell\\\\Cell\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Collection/CellsTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Functional\\\\ColumnWidthTest\\:\\:testReadColumnWidth\\(\\) has parameter \\$format with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Functional/ColumnWidthTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Functional\\\\CommentsTest\\:\\:testComments\\(\\) has parameter \\$format with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Functional/CommentsTest.php
-
-		-
-			message: "#^Cannot call method getPageSetup\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Functional/PrintAreaTest.php
-
-		-
-			message: "#^Parameter \\#1 \\$expected of static method PHPUnit\\\\Framework\\\\Assert\\:\\:assertInstanceOf\\(\\) expects class\\-string\\<object\\>, string given\\.$#"
-			count: 3
-			path: tests/PhpSpreadsheetTests/IOFactoryTest.php
-
-		-
-			message: "#^Cannot call method getValue\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\NamedFormula\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/NamedFormulaTest.php
-
-		-
-			message: "#^Cannot call method getValue\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\NamedRange\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/NamedRangeTest.php
-
-		-
-			message: "#^Property PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Ods\\\\OdsTest\\:\\:\\$spreadsheetData \\(PhpOffice\\\\PhpSpreadsheet\\\\Spreadsheet\\) in isset\\(\\) is not nullable\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
-
-		-
-			message: "#^Property PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Ods\\\\OdsTest\\:\\:\\$spreadsheetOdsTest \\(PhpOffice\\\\PhpSpreadsheet\\\\Spreadsheet\\) in isset\\(\\) is not nullable\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
-
-		-
-			message: "#^Unreachable statement \\- code above always terminates\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
-
-		-
-			message: "#^Argument of an invalid type array\\<int, string\\>\\|false supplied for foreach, only iterables are supported\\.$#"
-			count: 3
-			path: tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Security\\\\XmlScannerTest\\:\\:testInvalidXML\\(\\) has parameter \\$libxmlDisableEntityLoader with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Security\\\\XmlScannerTest\\:\\:testValidXML\\(\\) has parameter \\$libxmlDisableEntityLoader with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Xlsx\\\\AutoFilterTest\\:\\:getAutoFilterInstance\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Xlsx\\\\AutoFilterTest\\:\\:getWorksheetInstance\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Xlsx\\\\AutoFilterTest\\:\\:getXMLInstance\\(\\) has no return type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Xlsx\\\\AutoFilterTest\\:\\:getXMLInstance\\(\\) has parameter \\$ref with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
-
-		-
-			message: "#^Cannot call method getTitle\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Chart\\\\Chart\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
-
-		-
-			message: "#^Cannot call method getXAxisLabel\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Chart\\\\Chart\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
-
-		-
-			message: "#^Cannot call method getYAxisLabel\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Chart\\\\Chart\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
-
-		-
-			message: "#^Cannot call method getColor\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method getConditionalFormattingRuleExt\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 8
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method getMaximumConditionalFormatValueObject\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 13
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method getMinimumConditionalFormatValueObject\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 13
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method getShowValue\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method setMinimumConditionalFormatValueObject\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\ConditionalFormatting\\\\ConditionalDataBar\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
-
-		-
-			message: "#^Cannot call method getPlotArea\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Chart\\\\Chart\\|null\\.$#"
-			count: 2
-			path: tests/PhpSpreadsheetTests/Reader/Xlsx/SheetsXlsxChartTest.php
-
-		-
-			message: "#^Argument of an invalid type array\\<int, string\\>\\|false supplied for foreach, only iterables are supported\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Reader\\\\Xml\\\\XmlTest\\:\\:testInvalidSimpleXML\\(\\) has parameter \\$filename with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php
-
-		-
-			message: "#^Parameter \\#1 \\$currencyCode of static method PhpOffice\\\\PhpSpreadsheet\\\\Shared\\\\StringHelper\\:\\:setCurrencyCode\\(\\) expects string, null given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Shared/StringHelperTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\SpreadsheetTest\\:\\:testGetSheetByName\\(\\) has parameter \\$index with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/SpreadsheetTest.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\SpreadsheetTest\\:\\:testGetSheetByName\\(\\) has parameter \\$sheetName with no type specified\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/SpreadsheetTest.php
-
-		-
-			message: "#^Parameter \\#2 \\$value of method PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\AutoFilter\\\\Column\\:\\:setAttribute\\(\\) expects string, int given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Worksheet/AutoFilter/ColumnTest.php
-
-		-
-			message: "#^Parameter \\#2 \\$rowIndex of class PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\RowCellIterator constructor expects int, string given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
-
-		-
-			message: "#^Method PhpOffice\\\\PhpSpreadsheetTests\\\\Writer\\\\Html\\\\CallbackTest\\:\\:yellowBody\\(\\) should return string but returns string\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php
-
-		-
-			message: "#^Parameter \\#1 \\$haystack of function strpos expects string, string\\|false given\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php
-
-		-
-			message: "#^Cannot call method getColor\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\Font\\|null\\.$#"
-			count: 3
-			path: tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
-
-		-
-			message: "#^Cannot call method setSubScript\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\Font\\|null\\.$#"
-			count: 3
-			path: tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
-
-		-
-			message: "#^Cannot call method setSuperScript\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\Font\\|null\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
-
-		-
-			message: "#^Cannot call method setBold\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Style\\\\Font\\|null\\.$#"
-			count: 3
-			path: tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php
-
-		-
-			message: "#^Cannot call method getCell\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet\\|null\\.$#"
-			count: 4
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php
-
-		-
-			message: "#^Cannot call method getDrawingCollection\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\Worksheet\\|null\\.$#"
-			count: 4
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php
-
-		-
-			message: "#^Cannot access property \\$pageSetup on SimpleXMLElement\\|false\\.$#"
-			count: 1
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
-
-		-
-			message: "#^Cannot access property \\$sheetProtection on SimpleXMLElement\\|false\\.$#"
-			count: 5
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
-
-		-
-			message: "#^Parameter \\#1 \\$data of function simplexml_load_string expects string, string\\|false given\\.$#"
-			count: 2
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
-
-		-
-			message: "#^Cannot call method getExtension\\(\\) on PhpOffice\\\\PhpSpreadsheet\\\\Worksheet\\\\BaseDrawing\\|null\\.$#"
-			count: 2
-			path: tests/PhpSpreadsheetTests/Writer/Xlsx/WmfTest.php
diff --git a/src/PhpSpreadsheet/Calculation/Calculation.php b/src/PhpSpreadsheet/Calculation/Calculation.php
index 4a71f2b7..36adef01 100644
--- a/src/PhpSpreadsheet/Calculation/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation/Calculation.php
@@ -3226,6 +3226,7 @@ class Calculation
         if (self::$functionReplaceToExcel === null) {
             self::$functionReplaceToExcel = [];
             foreach (array_keys(self::$localeFunctions) as $excelFunctionName) {
+                // @phpstan-ignore-next-line
                 self::$functionReplaceToExcel[] = '$1' . trim($excelFunctionName) . '$2';
             }
             foreach (array_keys(self::$localeBoolean) as $excelBoolean) {
@@ -4490,6 +4491,7 @@ class Calculation
                             if ($operand1Data['reference'] === null) {
                                 if ((trim($operand1Data['value']) != '') && (is_numeric($operand1Data['value']))) {
                                     $operand1Data['reference'] = $cell->getColumn() . $operand1Data['value'];
+                                // @phpstan-ignore-next-line
                                 } elseif (trim($operand1Data['reference']) == '') {
                                     $operand1Data['reference'] = $cell->getCoordinate();
                                 } else {
@@ -4499,6 +4501,7 @@ class Calculation
                             if ($operand2Data['reference'] === null) {
                                 if ((trim($operand2Data['value']) != '') && (is_numeric($operand2Data['value']))) {
                                     $operand2Data['reference'] = $cell->getColumn() . $operand2Data['value'];
+                                // @phpstan-ignore-next-line
                                 } elseif (trim($operand2Data['reference']) == '') {
                                     $operand2Data['reference'] = $cell->getCoordinate();
                                 } else {
diff --git a/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php b/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
index 25a20870..adeb1b55 100644
--- a/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
+++ b/src/PhpSpreadsheet/Calculation/Engineering/BitWise.php
@@ -211,13 +211,14 @@ class BitWise
      *
      * @param mixed $value
      *
-     * @return float|int
+     * @return float
      */
     private static function validateBitwiseArgument($value)
     {
         $value = self::nullFalseTrueToNumber($value);
 
         if (is_numeric($value)) {
+            $value = (float) $value;
             if ($value == floor($value)) {
                 if (($value > 2 ** 48 - 1) || ($value < 0)) {
                     throw new Exception(ExcelError::NAN());
diff --git a/src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php b/src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
index 625784fd..1f848045 100644
--- a/src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
+++ b/src/PhpSpreadsheet/Calculation/LookupRef/RowColumnInformation.php
@@ -166,6 +166,7 @@ class RowColumnInformation
                 function ($value) {
                     return [$value];
                 },
+                // @phpstan-ignore-next-line
                 range($startAddress, $endAddress)
             );
         }
diff --git a/src/PhpSpreadsheet/Cell/Coordinate.php b/src/PhpSpreadsheet/Cell/Coordinate.php
index 6c3fce60..703eac08 100644
--- a/src/PhpSpreadsheet/Cell/Coordinate.php
+++ b/src/PhpSpreadsheet/Cell/Coordinate.php
@@ -148,6 +148,7 @@ abstract class Coordinate
         $exploded = explode(',', $range);
         $counter = count($exploded);
         for ($i = 0; $i < $counter; ++$i) {
+            // @phpstan-ignore-next-line
             $exploded[$i] = explode(':', $exploded[$i]);
         }
 
@@ -544,7 +545,7 @@ abstract class Coordinate
 
         // split range sets on intersection (space) or union (,) operators
         $tokens = preg_split('/([ ,])/', $rangeString, -1, PREG_SPLIT_DELIM_CAPTURE);
-        // separate the range sets and the operators into arrays
+        /** @phpstan-ignore-next-line */
         $split = array_chunk($tokens, 2);
         $ranges = array_column($split, 0);
         $operators = array_column($split, 1);
diff --git a/src/PhpSpreadsheet/Helper/Html.php b/src/PhpSpreadsheet/Helper/Html.php
index 4eecf99d..26526605 100644
--- a/src/PhpSpreadsheet/Helper/Html.php
+++ b/src/PhpSpreadsheet/Helper/Html.php
@@ -808,6 +808,7 @@ class Html
         if (isset($callbacks[$callbackTag])) {
             $elementHandler = $callbacks[$callbackTag];
             if (method_exists($this, $elementHandler)) {
+                // @phpstan-ignore-next-line
                 call_user_func([$this, $elementHandler], $element);
             }
         }
diff --git a/src/PhpSpreadsheet/Reader/Xls/MD5.php b/src/PhpSpreadsheet/Reader/Xls/MD5.php
index 3e15f641..a1108f92 100644
--- a/src/PhpSpreadsheet/Reader/Xls/MD5.php
+++ b/src/PhpSpreadsheet/Reader/Xls/MD5.php
@@ -71,6 +71,7 @@ class MD5
      */
     public function add(string $data): void
     {
+        /** @phpstan-ignore-next-line */
         $words = array_values(unpack('V16', $data));
 
         $A = $this->a;
diff --git a/src/PhpSpreadsheet/Shared/Drawing.php b/src/PhpSpreadsheet/Shared/Drawing.php
index 0d8ad618..3378958c 100644
--- a/src/PhpSpreadsheet/Shared/Drawing.php
+++ b/src/PhpSpreadsheet/Shared/Drawing.php
@@ -164,11 +164,15 @@ class Drawing
     {
         //    Load the image into a string
         $file = fopen($bmpFilename, 'rb');
+        /** @phpstan-ignore-next-line */
         $read = fread($file, 10);
+        // @phpstan-ignore-next-line
         while (!feof($file) && ($read != '')) {
+            // @phpstan-ignore-next-line
             $read .= fread($file, 1024);
         }
 
+        /** @phpstan-ignore-next-line */
         $temp = unpack('H*', $read);
         $hex = $temp[1];
         $header = substr($hex, 0, 108);
@@ -196,6 +200,8 @@ class Drawing
         $y = 1;
 
         //    Create newimage
+
+        /** @phpstan-ignore-next-line */
         $image = imagecreatetruecolor($width, $height);
 
         //    Grab the body from the image
@@ -241,7 +247,10 @@ class Drawing
             $b = hexdec($body[$i_pos] . $body[$i_pos + 1]);
 
             // Calculate and draw the pixel
+
+            /** @phpstan-ignore-next-line */
             $color = imagecolorallocate($image, $r, $g, $b);
+            // @phpstan-ignore-next-line
             imagesetpixel($image, $x, $height - $y, $color);
 
             // Raise the horizontal position
@@ -252,6 +261,7 @@ class Drawing
         unset($body);
 
         //    Return image-object
+        // @phpstan-ignore-next-line
         return $image;
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
index a96d4cda..ab78ef18 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
@@ -1134,6 +1134,7 @@ class Matrix
             $this->checkMatrixDimensions($M);
             for ($i = 0; $i < $this->m; ++$i) {
                 for ($j = 0; $j < $this->n; ++$j) {
+                    // @phpstan-ignore-next-line
                     $this->A[$i][$j] = trim($this->A[$i][$j], '"') . trim($M->get($i, $j), '"');
                 }
             }
diff --git a/src/PhpSpreadsheet/Shared/OLE.php b/src/PhpSpreadsheet/Shared/OLE.php
index ca975737..5c95d795 100644
--- a/src/PhpSpreadsheet/Shared/OLE.php
+++ b/src/PhpSpreadsheet/Shared/OLE.php
@@ -251,6 +251,7 @@ class OLE
      */
     private static function readInt1($fileHandle)
     {
+        // @phpstan-ignore-next-line
         [, $tmp] = unpack('c', fread($fileHandle, 1));
 
         return $tmp;
@@ -265,6 +266,7 @@ class OLE
      */
     private static function readInt2($fileHandle)
     {
+        // @phpstan-ignore-next-line
         [, $tmp] = unpack('v', fread($fileHandle, 2));
 
         return $tmp;
@@ -279,6 +281,7 @@ class OLE
      */
     private static function readInt4($fileHandle)
     {
+        // @phpstan-ignore-next-line
         [, $tmp] = unpack('V', fread($fileHandle, 4));
 
         return $tmp;
diff --git a/src/PhpSpreadsheet/Shared/OLE/ChainedBlockStream.php b/src/PhpSpreadsheet/Shared/OLE/ChainedBlockStream.php
index 43e4804d..ac9fcb00 100644
--- a/src/PhpSpreadsheet/Shared/OLE/ChainedBlockStream.php
+++ b/src/PhpSpreadsheet/Shared/OLE/ChainedBlockStream.php
@@ -160,6 +160,7 @@ class ChainedBlockStream
             $this->pos = $offset;
         } elseif ($whence == SEEK_CUR && -$offset <= $this->pos) {
             $this->pos += $offset;
+        // @phpstan-ignore-next-line
         } elseif ($whence == SEEK_END && -$offset <= count($this->data)) {
             $this->pos = strlen($this->data) + $offset;
         } else {
diff --git a/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php b/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
index 2c8eea5b..b10a0a10 100644
--- a/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
+++ b/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
@@ -114,6 +114,7 @@ class PolynomialBestFit extends BestFit
 
     public function getCoefficients($dp = 0)
     {
+        // @phpstan-ignore-next-line
         return array_merge([$this->getIntersect($dp)], $this->getSlope($dp));
     }
 
diff --git a/src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php b/src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php
index 5a47a86d..32fba53e 100644
--- a/src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php
+++ b/src/PhpSpreadsheet/Style/NumberFormat/DateFormatter.php
@@ -85,6 +85,8 @@ class DateFormatter
         $format = preg_replace_callback('/(?:^|")([^"]*)(?:$|")/', $callable, $format);
 
         // Only process the non-quoted blocks for date format characters
+
+        /** @phpstan-ignore-next-line */
         $blocks = explode('"', $format);
         foreach ($blocks as $key => &$block) {
             if ($key % 2 == 0) {
diff --git a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
index 2e3ea65b..076292f3 100644
--- a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
+++ b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
@@ -243,7 +243,7 @@ class Column
      * Set An AutoFilter Attribute.
      *
      * @param string $name Attribute Name
-     * @param string $value Attribute Value
+     * @param int|string $value Attribute Value
      *
      * @return $this
      */
diff --git a/src/PhpSpreadsheet/Worksheet/PageSetup.php b/src/PhpSpreadsheet/Worksheet/PageSetup.php
index 96407828..c23bfc59 100644
--- a/src/PhpSpreadsheet/Worksheet/PageSetup.php
+++ b/src/PhpSpreadsheet/Worksheet/PageSetup.php
@@ -640,6 +640,7 @@ class PageSetup
         if ($index == 0) {
             return $this->printArea;
         }
+        /** @phpstan-ignore-next-line */
         $printAreas = explode(',', $this->printArea);
         if (isset($printAreas[$index - 1])) {
             return $printAreas[$index - 1];
@@ -663,6 +664,7 @@ class PageSetup
         if ($index == 0) {
             return $this->printArea !== null;
         }
+        /** @phpstan-ignore-next-line */
         $printAreas = explode(',', $this->printArea);
 
         return isset($printAreas[$index - 1]);
@@ -683,6 +685,7 @@ class PageSetup
         if ($index == 0) {
             $this->printArea = null;
         } else {
+            /** @phpstan-ignore-next-line */
             $printAreas = explode(',', $this->printArea);
             if (isset($printAreas[$index - 1])) {
                 unset($printAreas[$index - 1]);
@@ -731,6 +734,7 @@ class PageSetup
             if ($index == 0) {
                 $this->printArea = $value;
             } else {
+                /** @phpstan-ignore-next-line */
                 $printAreas = explode(',', $this->printArea);
                 if ($index < 0) {
                     $index = count($printAreas) - abs($index) + 1;
@@ -745,6 +749,7 @@ class PageSetup
             if ($index == 0) {
                 $this->printArea = $this->printArea ? ($this->printArea . ',' . $value) : $value;
             } else {
+                /** @phpstan-ignore-next-line */
                 $printAreas = explode(',', $this->printArea);
                 if ($index < 0) {
                     $index = abs($index) - 1;
diff --git a/src/PhpSpreadsheet/Worksheet/Worksheet.php b/src/PhpSpreadsheet/Worksheet/Worksheet.php
index 362f20f0..4c7c7e60 100644
--- a/src/PhpSpreadsheet/Worksheet/Worksheet.php
+++ b/src/PhpSpreadsheet/Worksheet/Worksheet.php
@@ -567,6 +567,7 @@ class Worksheet implements IComparable
             $this->chartCollection[] = $chart;
         } else {
             // Insert the chart at the requested index
+            // @phpstan-ignore-next-line
             array_splice($this->chartCollection, $chartIndex, 0, [$chart]);
         }
 
@@ -1224,6 +1225,7 @@ class Worksheet implements IComparable
                     throw new Exception('Sheet not found for named range: ' . $namedRange->getName());
                 }
 
+                /** @phpstan-ignore-next-line */
                 $cellCoordinate = ltrim(substr($namedRange->getValue(), strrpos($namedRange->getValue(), '!')), '!');
                 $finalCoordinate = str_replace('$', '', $cellCoordinate);
             }
@@ -2767,6 +2769,7 @@ class Worksheet implements IComparable
     {
         $namedRange = $this->validateNamedRange($definedName);
         $workSheet = $namedRange->getWorksheet();
+        /** @phpstan-ignore-next-line */
         $cellRange = ltrim(substr($namedRange->getValue(), strrpos($namedRange->getValue(), '!')), '!');
         $cellRange = str_replace('$', '', $cellRange);
 
diff --git a/src/PhpSpreadsheet/Writer/Html.php b/src/PhpSpreadsheet/Writer/Html.php
index 9169d43b..629e3c0c 100644
--- a/src/PhpSpreadsheet/Writer/Html.php
+++ b/src/PhpSpreadsheet/Writer/Html.php
@@ -697,10 +697,12 @@ class Html extends BaseWriter
                 $imageResource = $drawing->getImageResource();
                 if ($imageResource) {
                     ob_start(); //  Let's start output buffering.
+                    // @phpstan-ignore-next-line
                     imagepng($imageResource); //  This will normally output the image, but because of ob_start(), it won't.
                     $contents = ob_get_contents(); //  Instead, output above is saved to $contents
                     ob_end_clean(); //  End the output buffer.
 
+                    /** @phpstan-ignore-next-line */
                     $dataUri = 'data:image/jpeg;base64,' . base64_encode($contents);
 
                     //  Because of the nature of tables, width is more important than height.
@@ -748,7 +750,7 @@ class Html extends BaseWriter
                     if ($fp = fopen($chartFileName, 'rb', 0)) {
                         $picture = fread($fp, filesize($chartFileName));
                         fclose($fp);
-                        // base64 encode the binary data
+                        /** @phpstan-ignore-next-line */
                         $base64 = base64_encode($picture);
                         $imageData = 'data:' . $imageDetails['mime'] . ';base64,' . $base64;
 
diff --git a/src/PhpSpreadsheet/Writer/Xls.php b/src/PhpSpreadsheet/Writer/Xls.php
index d134d690..b91e3859 100644
--- a/src/PhpSpreadsheet/Writer/Xls.php
+++ b/src/PhpSpreadsheet/Writer/Xls.php
@@ -434,6 +434,7 @@ class Xls extends BaseWriter
             case 1: // GIF, not supported by BIFF8, we convert to PNG
                 $blipType = BSE::BLIPTYPE_PNG;
                 ob_start();
+                // @phpstan-ignore-next-line
                 imagepng(imagecreatefromgif($filename));
                 $blipData = ob_get_contents();
                 ob_end_clean();
@@ -452,6 +453,7 @@ class Xls extends BaseWriter
             case 6: // Windows DIB (BMP), we convert to PNG
                 $blipType = BSE::BLIPTYPE_PNG;
                 ob_start();
+                // @phpstan-ignore-next-line
                 imagepng(SharedDrawing::imagecreatefrombmp($filename));
                 $blipData = ob_get_contents();
                 ob_end_clean();
diff --git a/src/PhpSpreadsheet/Writer/Xls/Worksheet.php b/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
index 979d3cb7..fcf7789a 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
@@ -989,6 +989,8 @@ class Worksheet extends BIFFwriter
         $options = pack('V', 0x03);
 
         // Convert URL to a null terminated wchar string
+
+        /** @phpstan-ignore-next-line */
         $url = implode("\0", preg_split("''", $url, -1, PREG_SPLIT_NO_EMPTY));
         $url = $url . "\0\0\0";
 
@@ -2387,6 +2389,7 @@ class Worksheet extends BIFFwriter
         $data = pack('Vvvvv', 0x000c, $width, $height, 0x01, 0x18);
         for ($j = $height; --$j;) {
             for ($i = 0; $i < $width; ++$i) {
+                /** @phpstan-ignore-next-line */
                 $color = imagecolorsforindex($image, imagecolorat($image, $i, $j));
                 foreach (['red', 'green', 'blue'] as $key) {
                     $color[$key] = $color[$key] + (int) round((255 - $color[$key]) * $color['alpha'] / 127);
@@ -2427,6 +2430,8 @@ class Worksheet extends BIFFwriter
         }
 
         // The first 2 bytes are used to identify the bitmap.
+
+        /** @phpstan-ignore-next-line */
         $identity = unpack('A2ident', $data);
         if ($identity['ident'] != 'BM') {
             throw new WriterException("$bitmap doesn't appear to be a valid bitmap image.\n");
diff --git a/src/PhpSpreadsheet/Writer/Xlsx.php b/src/PhpSpreadsheet/Writer/Xlsx.php
index 4f506070..38cd01c7 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx.php
@@ -501,8 +501,10 @@ class Xlsx extends BaseWriter
                 $zipContent['xl/media/' . $this->getDrawingHashTable()->getByIndex($i)->getIndexedFilename()] = $imageContents;
             } elseif ($this->getDrawingHashTable()->getByIndex($i) instanceof MemoryDrawing) {
                 ob_start();
+                /** @var callable */
+                $callable = $this->getDrawingHashTable()->getByIndex($i)->getRenderingFunction();
                 call_user_func(
-                    $this->getDrawingHashTable()->getByIndex($i)->getRenderingFunction(),
+                    $callable,
                     $this->getDrawingHashTable()->getByIndex($i)->getImageResource()
                 );
                 $imageContents = ob_get_contents();
diff --git a/tests/PhpSpreadsheetTests/Calculation/Engine/RangeTest.php b/tests/PhpSpreadsheetTests/Calculation/Engine/RangeTest.php
index c27d16af..becf1d71 100644
--- a/tests/PhpSpreadsheetTests/Calculation/Engine/RangeTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/Engine/RangeTest.php
@@ -9,6 +9,9 @@ use PHPUnit\Framework\TestCase;
 
 class RangeTest extends TestCase
 {
+    /** @var string */
+    private $incompleteMessage = 'Must be revisited';
+
     /**
      * @var Spreadsheet
      */
@@ -140,7 +143,9 @@ class RangeTest extends TestCase
      */
     public function testCompositeNamedRangeEvaluation(string $composite, int $expectedSum, int $expectedCount): void
     {
-        self::markTestSkipped('must be revisited.');
+        if ($this->incompleteMessage !== '') {
+            self::markTestIncomplete($this->incompleteMessage);
+        }
 
         $workSheet = $this->spreadSheet->getActiveSheet();
         $this->spreadSheet->addNamedRange(new NamedRange('COMPOSITE', $workSheet, $composite));
diff --git a/tests/PhpSpreadsheetTests/Collection/CellsTest.php b/tests/PhpSpreadsheetTests/Collection/CellsTest.php
index 5e656cf5..0183e16a 100644
--- a/tests/PhpSpreadsheetTests/Collection/CellsTest.php
+++ b/tests/PhpSpreadsheetTests/Collection/CellsTest.php
@@ -20,7 +20,8 @@ class CellsTest extends TestCase
         // Assert empty state
         self::assertEquals([], $collection->getCoordinates(), 'cell list should be empty');
         self::assertEquals([], $collection->getSortedCoordinates(), 'sorted cell list should be empty');
-        self::assertNull($collection->get('B2'), 'getting non-existing cell must return null');
+        $getB2 = $collection->get('B2');
+        self::assertNull($getB2, 'getting non-existing cell must return null');
         self::assertFalse($collection->has('B2'), 'non-existing cell should be non-existent');
 
         // Add one cell
@@ -44,6 +45,7 @@ class CellsTest extends TestCase
         $collection2 = $collection->cloneCellCollection($sheet2);
         self::assertTrue($collection2->has('A1'));
         $copiedCell2 = $collection2->get('A1');
+        self::assertNotNull($copiedCell2);
         self::assertNotSame($cell2, $copiedCell2, 'copied cell should not be the same object any more');
         self::assertSame($collection2, $copiedCell2->getParent(), 'copied cell should be owned by the copied collection');
         self::assertSame('A1', $copiedCell2->getCoordinate(), 'copied cell should keep attributes');
diff --git a/tests/PhpSpreadsheetTests/Functional/ColumnWidthTest.php b/tests/PhpSpreadsheetTests/Functional/ColumnWidthTest.php
index 41122885..f9b2c7b6 100644
--- a/tests/PhpSpreadsheetTests/Functional/ColumnWidthTest.php
+++ b/tests/PhpSpreadsheetTests/Functional/ColumnWidthTest.php
@@ -17,7 +17,7 @@ class ColumnWidthTest extends AbstractFunctional
     /**
      * @dataProvider providerFormats
      */
-    public function testReadColumnWidth($format): void
+    public function testReadColumnWidth(string $format): void
     {
         // create new sheet with column width
         $spreadsheet = new Spreadsheet();
diff --git a/tests/PhpSpreadsheetTests/Functional/CommentsTest.php b/tests/PhpSpreadsheetTests/Functional/CommentsTest.php
index 03be3e00..095a3036 100644
--- a/tests/PhpSpreadsheetTests/Functional/CommentsTest.php
+++ b/tests/PhpSpreadsheetTests/Functional/CommentsTest.php
@@ -22,7 +22,7 @@ class CommentsTest extends AbstractFunctional
      *
      * @dataProvider providerFormats
      */
-    public function testComments($format): void
+    public function testComments(string $format): void
     {
         $spreadsheet = new Spreadsheet();
 
diff --git a/tests/PhpSpreadsheetTests/Functional/PrintAreaTest.php b/tests/PhpSpreadsheetTests/Functional/PrintAreaTest.php
index 93753762..700c7c7f 100644
--- a/tests/PhpSpreadsheetTests/Functional/PrintAreaTest.php
+++ b/tests/PhpSpreadsheetTests/Functional/PrintAreaTest.php
@@ -44,15 +44,23 @@ class PrintAreaTest extends AbstractFunctional
             $reader->setLoadSheetsOnly(['Sheet 1', 'Sheet 3', 'Sheet 4', 'Sheet 5', 'Sheet 6']);
         });
 
-        $actual1 = $reloadedSpreadsheet->getSheetByName('Sheet 1')->getPageSetup()->getPrintArea();
-        $actual3 = $reloadedSpreadsheet->getSheetByName('Sheet 3')->getPageSetup()->getPrintArea();
-        $actual4 = $reloadedSpreadsheet->getSheetByName('Sheet 4')->getPageSetup()->getPrintArea();
-        $actual5 = $reloadedSpreadsheet->getSheetByName('Sheet 5')->getPageSetup()->getPrintArea();
-        $actual6 = $reloadedSpreadsheet->getSheetByName('Sheet 6')->getPageSetup()->getPrintArea();
+        $actual1 = self::getPrintArea($reloadedSpreadsheet, 'Sheet 1');
+        $actual3 = self::getPrintArea($reloadedSpreadsheet, 'Sheet 3');
+        $actual4 = self::getPrintArea($reloadedSpreadsheet, 'Sheet 4');
+        $actual5 = self::getPrintArea($reloadedSpreadsheet, 'Sheet 5');
+        $actual6 = self::getPrintArea($reloadedSpreadsheet, 'Sheet 6');
         self::assertSame('A1:B1', $actual1, 'should be able to write and read normal page setup');
         self::assertSame('A3:B3', $actual3, 'should be able to write and read page setup even when skipping sheets');
         self::assertSame('A4:B4,D1:E4', $actual4, 'should be able to write and read page setup with multiple print areas');
         self::assertSame('A1:J10', $actual5, 'add by column and row');
         self::assertSame('A1:J10,L1:L10', $actual6, 'multiple add by column and row');
     }
+
+    private static function getPrintArea(Spreadsheet $spreadsheet, string $name): string
+    {
+        $sheet = $spreadsheet->getSheetByName($name);
+        self::assertNotNull($sheet, "Unable to get sheet $name");
+
+        return $sheet->getPageSetup()->getPrintArea();
+    }
 }
diff --git a/tests/PhpSpreadsheetTests/IOFactoryTest.php b/tests/PhpSpreadsheetTests/IOFactoryTest.php
index b8c6ff83..958c6eb0 100644
--- a/tests/PhpSpreadsheetTests/IOFactoryTest.php
+++ b/tests/PhpSpreadsheetTests/IOFactoryTest.php
@@ -21,7 +21,7 @@ class IOFactoryTest extends TestCase
     {
         $spreadsheet = new Spreadsheet();
         $actual = IOFactory::createWriter($spreadsheet, $name);
-        self::assertInstanceOf($expected, $actual);
+        self::assertSame($expected, get_class($actual));
     }
 
     public function providerCreateWriter(): array
@@ -55,7 +55,7 @@ class IOFactoryTest extends TestCase
     public function testCreateReader($name, $expected): void
     {
         $actual = IOFactory::createReader($name);
-        self::assertInstanceOf($expected, $actual);
+        self::assertSame($expected, get_class($actual));
     }
 
     public function providerCreateReader(): array
@@ -102,7 +102,7 @@ class IOFactoryTest extends TestCase
     public function testCreateReaderForFile($file, $expectedName, $expectedClass): void
     {
         $actual = IOFactory::createReaderForFile($file);
-        self::assertInstanceOf($expectedClass, $actual);
+        self::assertSame($expectedClass, get_class($actual));
     }
 
     /**
diff --git a/tests/PhpSpreadsheetTests/NamedFormulaTest.php b/tests/PhpSpreadsheetTests/NamedFormulaTest.php
index 44254829..4c4a6b11 100644
--- a/tests/PhpSpreadsheetTests/NamedFormulaTest.php
+++ b/tests/PhpSpreadsheetTests/NamedFormulaTest.php
@@ -48,9 +48,11 @@ class NamedFormulaTest extends TestCase
         );
 
         self::assertCount(1, $this->spreadsheet->getNamedFormulae());
+        $formula = $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getActiveSheet());
+        self::assertNotNull($formula);
         self::assertSame(
             '=16%',
-            $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getActiveSheet())->getValue()
+            $formula->getValue()
         );
     }
 
@@ -64,13 +66,17 @@ class NamedFormulaTest extends TestCase
         );
 
         self::assertCount(2, $this->spreadsheet->getNamedFormulae());
+        $formula = $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getActiveSheet());
+        self::assertNotNull($formula);
         self::assertSame(
             '=19%',
-            $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getActiveSheet())->getValue()
+            $formula->getValue()
         );
+        $formula = $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getSheetByName('Sheet #2'));
+        self::assertNotNull($formula);
         self::assertSame(
             '=16%',
-            $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getSheetByName('Sheet #2'))->getValue()
+            $formula->getValue()
         );
     }
 
@@ -100,9 +106,11 @@ class NamedFormulaTest extends TestCase
         $this->spreadsheet->removeNamedFormula('Foo', $this->spreadsheet->getActiveSheet());
 
         self::assertCount(1, $this->spreadsheet->getNamedFormulae());
+        $formula = $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getSheetByName('Sheet #2'));
+        self::assertNotNull($formula);
         self::assertSame(
             '=16%',
-            $this->spreadsheet->getNamedFormula('foo', $this->spreadsheet->getSheetByName('Sheet #2'))->getValue()
+            $formula->getValue()
         );
     }
 
@@ -118,9 +126,11 @@ class NamedFormulaTest extends TestCase
         $this->spreadsheet->removeNamedFormula('Foo', $this->spreadsheet->getSheetByName('Sheet #2'));
 
         self::assertCount(1, $this->spreadsheet->getNamedFormulae());
+        $formula = $this->spreadsheet->getNamedFormula('foo');
+        self::assertNotNull($formula);
         self::assertSame(
             '=19%',
-            $this->spreadsheet->getNamedFormula('foo')->getValue()
+            $formula->getValue()
         );
     }
 }
diff --git a/tests/PhpSpreadsheetTests/NamedRangeTest.php b/tests/PhpSpreadsheetTests/NamedRangeTest.php
index 62cd735b..c72b7b73 100644
--- a/tests/PhpSpreadsheetTests/NamedRangeTest.php
+++ b/tests/PhpSpreadsheetTests/NamedRangeTest.php
@@ -48,9 +48,11 @@ class NamedRangeTest extends TestCase
         );
 
         self::assertCount(1, $this->spreadsheet->getNamedRanges());
+        $range = $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getActiveSheet());
+        self::assertNotNull($range);
         self::assertSame(
             '=B1',
-            $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getActiveSheet())->getValue()
+            $range->getValue()
         );
     }
 
@@ -64,13 +66,17 @@ class NamedRangeTest extends TestCase
         );
 
         self::assertCount(2, $this->spreadsheet->getNamedRanges());
+        $range = $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getActiveSheet());
+        self::assertNotNull($range);
         self::assertSame(
             '=A1',
-            $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getActiveSheet())->getValue()
+            $range->getValue()
         );
+        $range = $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getSheetByName('Sheet #2'));
+        self::assertNotNull($range);
         self::assertSame(
             '=B1',
-            $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getSheetByName('Sheet #2'))->getValue()
+            $range->getValue()
         );
     }
 
@@ -100,9 +106,11 @@ class NamedRangeTest extends TestCase
         $this->spreadsheet->removeNamedRange('Foo', $this->spreadsheet->getActiveSheet());
 
         self::assertCount(1, $this->spreadsheet->getNamedRanges());
+        $sheet = $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getSheetByName('Sheet #2'));
+        self::assertNotNull($sheet);
         self::assertSame(
             '=B1',
-            $this->spreadsheet->getNamedRange('foo', $this->spreadsheet->getSheetByName('Sheet #2'))->getValue()
+            $sheet->getValue()
         );
     }
 
@@ -118,9 +126,11 @@ class NamedRangeTest extends TestCase
         $this->spreadsheet->removeNamedRange('Foo', $this->spreadsheet->getSheetByName('Sheet #2'));
 
         self::assertCount(1, $this->spreadsheet->getNamedRanges());
+        $range = $this->spreadsheet->getNamedRange('foo');
+        self::AssertNotNull($range);
         self::assertSame(
             '=A1',
-            $this->spreadsheet->getNamedRange('foo')->getValue()
+            $range->getValue()
         );
     }
 }
diff --git a/tests/PhpSpreadsheetTests/Reader/Csv/CsvNumberFormatLocaleTest.php b/tests/PhpSpreadsheetTests/Reader/Csv/CsvNumberFormatLocaleTest.php
index 1ac093c4..55094486 100644
--- a/tests/PhpSpreadsheetTests/Reader/Csv/CsvNumberFormatLocaleTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Csv/CsvNumberFormatLocaleTest.php
@@ -96,6 +96,8 @@ class CsvNumberFormatLocaleTest extends TestCase
      * @dataProvider providerNumberValueConversionTest
      *
      * @param mixed $expectedValue
+     *
+     * @runInSeparateProcess
      */
     public function testNumberValueConversion($expectedValue, string $cellAddress): void
     {
diff --git a/tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php b/tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
index a7f1466c..47d43991 100644
--- a/tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Ods/OdsTest.php
@@ -15,6 +15,9 @@ use PHPUnit\Framework\TestCase;
  */
 class OdsTest extends TestCase
 {
+    /** @var string */
+    private $incompleteMessage = 'Features not implemented yet';
+
     /**
      * @var string
      */
@@ -32,12 +35,12 @@ class OdsTest extends TestCase
     }
 
     /**
-     * @var Spreadsheet
+     * @var ?Spreadsheet
      */
     private $spreadsheetOdsTest;
 
     /**
-     * @var Spreadsheet
+     * @var ?Spreadsheet
      */
     private $spreadsheetData;
 
@@ -46,13 +49,13 @@ class OdsTest extends TestCase
      */
     private function loadOdsTestFile()
     {
-        if (!isset($this->spreadsheetOdsTest)) {
-            $filename = 'samples/templates/OOCalcTest.ods';
-
-            // Load into this instance
-            $reader = new Ods();
-            $this->spreadsheetOdsTest = $reader->loadIntoExisting($filename, new Spreadsheet());
+        if (isset($this->spreadsheetOdsTest)) {
+            return $this->spreadsheetOdsTest;
         }
+        $filename = 'samples/templates/OOCalcTest.ods';
+        // Load into this instance
+        $reader = new Ods();
+        $this->spreadsheetOdsTest = $reader->loadIntoExisting($filename, new Spreadsheet());
 
         return $this->spreadsheetOdsTest;
     }
@@ -62,13 +65,13 @@ class OdsTest extends TestCase
      */
     protected function loadDataFile()
     {
-        if (!isset($this->spreadsheetData)) {
-            $filename = 'tests/data/Reader/Ods/data.ods';
-
-            // Load into this instance
-            $reader = new Ods();
-            $this->spreadsheetData = $reader->load($filename);
+        if (isset($this->spreadsheetData)) {
+            return $this->spreadsheetData;
         }
+        $filename = 'tests/data/Reader/Ods/data.ods';
+        // Load into this instance
+        $reader = new Ods();
+        $this->spreadsheetData = $reader->load($filename);
 
         return $this->spreadsheetData;
     }
@@ -271,8 +274,9 @@ class OdsTest extends TestCase
 
     public function testReadBoldItalicUnderline(): void
     {
-        self::markTestIncomplete('Features not implemented yet');
-
+        if ($this->incompleteMessage !== '') {
+            self::markTestIncomplete($this->incompleteMessage);
+        }
         $spreadsheet = $this->loadOdsTestFile();
         $firstSheet = $spreadsheet->getSheet(0);
 
diff --git a/tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php b/tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
index 39bc864c..8b034b91 100644
--- a/tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Security/XmlScannerTest.php
@@ -24,7 +24,7 @@ class XmlScannerTest extends TestCase
      * @param mixed $filename
      * @param mixed $expectedResult
      */
-    public function testValidXML($filename, $expectedResult, $libxmlDisableEntityLoader): void
+    public function testValidXML($filename, $expectedResult, bool $libxmlDisableEntityLoader): void
     {
         // php 8.+ deprecated libxml_disable_entity_loader() - It's on by default
         if (\PHP_VERSION_ID < 80000) {
@@ -44,7 +44,9 @@ class XmlScannerTest extends TestCase
     public function providerValidXML(): array
     {
         $tests = [];
-        foreach (glob('tests/data/Reader/Xml/XEETestValid*.xml') as $file) {
+        $glob = glob('tests/data/Reader/Xml/XEETestValid*.xml');
+        self::assertNotFalse($glob);
+        foreach ($glob as $file) {
             $filename = realpath($file);
             $expectedResult = file_get_contents($file);
             $tests[basename($file) . '_libxml_entity_loader_disabled'] = [$filename, $expectedResult, true];
@@ -59,7 +61,7 @@ class XmlScannerTest extends TestCase
      *
      * @param mixed $filename
      */
-    public function testInvalidXML($filename, $libxmlDisableEntityLoader): void
+    public function testInvalidXML($filename, bool $libxmlDisableEntityLoader): void
     {
         $this->expectException(\PhpOffice\PhpSpreadsheet\Reader\Exception::class);
 
@@ -81,7 +83,9 @@ class XmlScannerTest extends TestCase
     public function providerInvalidXML(): array
     {
         $tests = [];
-        foreach (glob('tests/data/Reader/Xml/XEETestInvalidUTF*.xml') as $file) {
+        $glob = glob('tests/data/Reader/Xml/XEETestInvalidUTF*.xml');
+        self::assertNotFalse($glob);
+        foreach ($glob as $file) {
             $filename = realpath($file);
             $tests[basename($file) . '_libxml_entity_loader_disabled'] = [$filename, true];
             $tests[basename($file) . '_libxml_entity_loader_enabled'] = [$filename, false];
@@ -128,7 +132,9 @@ class XmlScannerTest extends TestCase
     public function providerValidXMLForCallback(): array
     {
         $tests = [];
-        foreach (glob('tests/data/Reader/Xml/SecurityScannerWithCallback*.xml') as $file) {
+        $glob = glob('tests/data/Reader/Xml/SecurityScannerWithCallback*.xml');
+        self::assertNotFalse($glob);
+        foreach ($glob as $file) {
             $tests[basename($file)] = [realpath($file), file_get_contents($file)];
         }
 
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
index 7287b711..1bca8508 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/AutoFilterTest.php
@@ -10,14 +10,7 @@ use SimpleXMLElement;
 
 class AutoFilterTest extends TestCase
 {
-    private function getWorksheetInstance()
-    {
-        return $this->getMockBuilder(Worksheet::class)
-            ->disableOriginalConstructor()
-            ->getMock();
-    }
-
-    private function getXMLInstance($ref)
+    private function getXMLInstance(string $ref): SimpleXMLElement
     {
         return new SimpleXMLElement(
             '<?xml version="1.0" encoding="UTF-8"?>' .
@@ -27,15 +20,6 @@ class AutoFilterTest extends TestCase
         );
     }
 
-    private function getAutoFilterInstance()
-    {
-        $instance = $this->getMockBuilder(WorksheetAutoFilter::class)
-            ->disableOriginalConstructor()
-            ->getMock();
-
-        return $instance;
-    }
-
     public function loadDataProvider(): array
     {
         return [
@@ -53,12 +37,16 @@ class AutoFilterTest extends TestCase
      */
     public function testLoad($ref, $expectedReadAutoFilterCalled, $expectedRef): void
     {
-        $worksheetAutoFilter = $this->getAutoFilterInstance();
+        $worksheetAutoFilter = $this->getMockBuilder(WorksheetAutoFilter::class)
+            ->disableOriginalConstructor()
+            ->getMock();
         $worksheetAutoFilter->expects(self::exactly($expectedReadAutoFilterCalled ? 1 : 0))
             ->method('setRange')
             ->with($expectedRef);
 
-        $worksheet = $this->getWorksheetInstance();
+        $worksheet = $this->getMockBuilder(Worksheet::class)
+            ->disableOriginalConstructor()
+            ->getMock();
         $worksheet->expects(self::exactly($expectedReadAutoFilterCalled ? 1 : 0))
             ->method('getAutoFilter')
             ->willReturn($worksheetAutoFilter);
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
index 5cde677d..3d881ecf 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/ChartsTitleTest.php
@@ -26,6 +26,7 @@ class ChartsTitleTest extends TestCase
 
         // No title or axis labels
         $chart1 = $charts[0];
+        self::assertNotNull($chart1);
         $title = self::getTitleText($chart1->getTitle());
         self::assertEmpty($title);
         self::assertEmpty(self::getTitleText($chart1->getXAxisLabel()));
@@ -33,6 +34,7 @@ class ChartsTitleTest extends TestCase
 
         // Title, no axis labels
         $chart2 = $charts[1];
+        self::assertNotNull($chart2);
 
         self::assertEquals('Chart with Title and no Axis Labels', self::getTitleText($chart2->getTitle()));
         self::assertEmpty(self::getTitleText($chart2->getXAxisLabel()));
@@ -40,18 +42,21 @@ class ChartsTitleTest extends TestCase
 
         // No title, only horizontal axis label
         $chart3 = $charts[2];
+        self::assertNotNull($chart3);
         self::assertEmpty(self::getTitleText($chart3->getTitle()));
         self::assertEquals('Horizontal Axis Title Only', self::getTitleText($chart3->getXAxisLabel()));
         self::assertEmpty(self::getTitleText($chart3->getYAxisLabel()));
 
         // No title, only vertical axis label
         $chart4 = $charts[3];
+        self::assertNotNull($chart4);
         self::assertEmpty(self::getTitleText($chart4->getTitle()));
         self::assertEquals('Vertical Axis Title Only', self::getTitleText($chart4->getYAxisLabel()));
         self::assertEmpty(self::getTitleText($chart4->getXAxisLabel()));
 
         // Title and both axis labels
         $chart5 = $charts[4];
+        self::assertNotNull($chart5);
         self::assertEquals('Complete Annotations', self::getTitleText($chart5->getTitle()));
         self::assertEquals('Horizontal Axis Title', self::getTitleText($chart5->getXAxisLabel()));
         self::assertEquals('Vertical Axis Title', self::getTitleText($chart5->getYAxisLabel()));
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
index 57fbdad2..4b051dd0 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/ConditionalFormattingDataBarXlsxTest.php
@@ -60,7 +60,9 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
         $cond1 = new Conditional();
         $cond1->setConditionType(Conditional::CONDITION_DATABAR);
         $cond1->setDataBar(new ConditionalDataBar());
-        $cond1->getDataBar()
+        $dataBar = $cond1->getDataBar();
+        self::assertNotNull($dataBar);
+        $dataBar
             ->setMinimumConditionalFormatValueObject(new ConditionalFormatValueObject('min'))
             ->setMaximumConditionalFormatValueObject(new ConditionalFormatValueObject('max'))
             ->setColor(Color::COLOR_GREEN);
@@ -83,6 +85,7 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
         self::assertNotEmpty($conditionalRule->getDataBar());
 
         $dataBar = $conditionalRule->getDataBar();
+        self::assertNotNull($dataBar);
         self::assertNotEmpty($dataBar->getMinimumConditionalFormatValueObject());
         self::assertNotEmpty($dataBar->getMaximumConditionalFormatValueObject());
         self::assertEquals('min', $dataBar->getMinimumConditionalFormatValueObject()->getType());
@@ -105,6 +108,7 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
 
         self::assertNotEmpty($dataBar);
         self::assertEquals(Conditional::CONDITION_DATABAR, $conditionalRule->getConditionType());
+        self::assertNotNull($dataBar);
         self::assertNotEmpty($dataBar->getMinimumConditionalFormatValueObject());
         self::assertNotEmpty($dataBar->getMaximumConditionalFormatValueObject());
         self::assertEquals('min', $dataBar->getMinimumConditionalFormatValueObject()->getType());
@@ -160,6 +164,7 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
 
         self::assertNotEmpty($dataBar);
         self::assertEquals(Conditional::CONDITION_DATABAR, $conditionalRule->getConditionType());
+        self::assertNotNull($dataBar);
         self::assertNotEmpty($dataBar->getMinimumConditionalFormatValueObject());
         self::assertNotEmpty($dataBar->getMaximumConditionalFormatValueObject());
         self::assertEquals('num', $dataBar->getMinimumConditionalFormatValueObject()->getType());
@@ -218,6 +223,7 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
 
         self::assertNotEmpty($dataBar);
         self::assertEquals(Conditional::CONDITION_DATABAR, $conditionalRule->getConditionType());
+        self::assertNotNull($dataBar);
         self::assertNotEmpty($dataBar->getMinimumConditionalFormatValueObject());
         self::assertNotEmpty($dataBar->getMaximumConditionalFormatValueObject());
         self::assertEquals('min', $dataBar->getMinimumConditionalFormatValueObject()->getType());
@@ -278,6 +284,7 @@ class ConditionalFormattingDataBarXlsxTest extends TestCase
         self::assertNotEmpty($dataBar);
         self::assertEquals(Conditional::CONDITION_DATABAR, $conditionalRule->getConditionType());
 
+        self::assertNotNull($dataBar);
         self::assertTrue($dataBar->getShowValue());
         self::assertNotEmpty($dataBar->getMinimumConditionalFormatValueObject());
         self::assertNotEmpty($dataBar->getMaximumConditionalFormatValueObject());
diff --git a/tests/PhpSpreadsheetTests/Reader/Xlsx/SheetsXlsxChartTest.php b/tests/PhpSpreadsheetTests/Reader/Xlsx/SheetsXlsxChartTest.php
index d701c3c7..0cbd103d 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xlsx/SheetsXlsxChartTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xlsx/SheetsXlsxChartTest.php
@@ -21,6 +21,7 @@ class SheetsXlsxChartTest extends TestCase
         self::assertCount(2, $charts);
 
         $chart1 = $charts[0];
+        self::assertNotNull($chart1);
         $pa1 = $chart1->getPlotArea();
         self::assertEquals(2, $pa1->getPlotSeriesCount());
 
@@ -32,6 +33,7 @@ class SheetsXlsxChartTest extends TestCase
         self::assertCount(2, $pg1->getPlotCategories());
 
         $chart2 = $charts[1];
+        self::assertNotNull($chart2);
         $pa1 = $chart2->getPlotArea();
         self::assertEquals(2, $pa1->getPlotSeriesCount());
 
diff --git a/tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php b/tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php
index a0b05a56..6936b241 100644
--- a/tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/Xml/XmlTest.php
@@ -11,7 +11,7 @@ class XmlTest extends TestCase
     /**
      * @dataProvider providerInvalidSimpleXML
      */
-    public function testInvalidSimpleXML($filename): void
+    public function testInvalidSimpleXML(string $filename): void
     {
         $this->expectException(\PhpOffice\PhpSpreadsheet\Reader\Exception::class);
 
@@ -22,7 +22,9 @@ class XmlTest extends TestCase
     public function providerInvalidSimpleXML(): array
     {
         $tests = [];
-        foreach (glob('tests/data/Reader/Xml/XEETestInvalidSimpleXML*.xml') as $file) {
+        $glob = glob('tests/data/Reader/Xml/XEETestInvalidSimpleXML*.xml');
+        self::assertNotFalse($glob);
+        foreach ($glob as $file) {
             $tests[basename($file)] = [realpath($file)];
         }
 
diff --git a/tests/PhpSpreadsheetTests/Shared/StringHelperTest.php b/tests/PhpSpreadsheetTests/Shared/StringHelperTest.php
index 92f197a2..bcbcd5d2 100644
--- a/tests/PhpSpreadsheetTests/Shared/StringHelperTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/StringHelperTest.php
@@ -28,9 +28,6 @@ class StringHelperTest extends TestCase
         $this->currencyCode = StringHelper::getCurrencyCode();
         $this->decimalSeparator = StringHelper::getDecimalSeparator();
         $this->thousandsSeparator = StringHelper::getThousandsSeparator();
-
-        // Reset Currency Code
-        StringHelper::setCurrencyCode(null);
     }
 
     protected function tearDown(): void
diff --git a/tests/PhpSpreadsheetTests/SpreadsheetTest.php b/tests/PhpSpreadsheetTests/SpreadsheetTest.php
index 7f159d67..4a1b7393 100644
--- a/tests/PhpSpreadsheetTests/SpreadsheetTest.php
+++ b/tests/PhpSpreadsheetTests/SpreadsheetTest.php
@@ -43,7 +43,7 @@ class SpreadsheetTest extends TestCase
     /**
      * @dataProvider dataProviderForSheetNames
      */
-    public function testGetSheetByName($index, $sheetName): void
+    public function testGetSheetByName(int $index, string $sheetName): void
     {
         self::assertSame($this->object->getSheet($index), $this->object->getSheetByName($sheetName));
     }
diff --git a/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php b/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
index 52183168..063e5b88 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowCellIterator2Test.php
@@ -55,7 +55,7 @@ class RowCellIterator2Test extends TestCase
         $sheet->getCell('B2')->setValue('cellb2');
         $sheet->getCell('F2')->setValue('cellf2');
 
-        $iterator = new RowCellIterator($sheet, '3');
+        $iterator = new RowCellIterator($sheet, 3);
         if (isset($existing)) {
             $iterator->setIterateOnlyExistingCells($existing);
         }
diff --git a/tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php b/tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php
index ae71ca55..16ee24e8 100644
--- a/tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Html/CallbackTest.php
@@ -20,7 +20,7 @@ body {
 
 EOF;
 
-        return preg_replace('~</head>~', "$newstyle</head>", $html);
+        return preg_replace('~</head>~', "$newstyle</head>", $html) ?? '';
     }
 
     public function testSetAndReset(): void
@@ -46,6 +46,7 @@ EOF;
         $writer->save($oufil);
         $html4 = file_get_contents($oufil);
         unlink($oufil);
+        self::assertNotFalse($html4);
         self::assertNotFalse(strpos($html4, 'background-color: yellow'));
 
         $this->writeAndReload($spreadsheet, 'Html');
diff --git a/tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php b/tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
index 2fa41953..08af7c59 100644
--- a/tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Html/GridlinesTest.php
@@ -101,9 +101,12 @@ class GridlinesTest extends Functional\AbstractFunctional
         $sheet = $spreadsheet->getActiveSheet();
         $emc2 = new \PhpOffice\PhpSpreadsheet\RichText\RichText();
         $part1 = $emc2->createTextRun('e=mc');
-        $part1->getFont()->getColor()->setARGB(Color::COLOR_BLUE);
+        $font = $part1->getFont();
+        self::assertNotNull($font);
+        $font->getColor()->setARGB(Color::COLOR_BLUE);
         $part2 = $emc2->createTextRun('2');
         $font = $part2->getFont();
+        self::assertNotNull($font);
         $font->getColor()->setARGB(Color::COLOR_DARKGREEN);
         $font->setSuperScript(true);
         $sheet->setCellValue('A1', $emc2);
@@ -111,6 +114,7 @@ class GridlinesTest extends Functional\AbstractFunctional
         $h2o->createTextRun('H');
         $part2 = $h2o->createTextRun('2');
         $font = $part2->getFont();
+        self::assertNotNull($font);
         $font->setSubScript(true);
         $font->getColor()->setARGB(Color::COLOR_RED);
         $h2o->createTextRun('O');
@@ -119,10 +123,13 @@ class GridlinesTest extends Functional\AbstractFunctional
         $h2so4->createTextRun('H');
         $part2 = $h2so4->createTextRun('2');
         $font = $part2->getFont();
+        self::assertNotNull($font);
         $font->setSubScript(true);
         $h2so4->createTextRun('SO');
         $part4 = $h2so4->createTextRun('4');
-        $part4->getFont()->setSubScript(true);
+        $font = $part4->getFont();
+        self::assertNotNull($font);
+        $font->setSubScript(true);
         $sheet->setCellValue('A3', $h2so4);
         $sheet->setCellValue('A4', '5');
         $sheet->getCell('A4')->getStyle()->getFont()->setSuperScript(true);
diff --git a/tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php b/tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php
index a4f474fa..0aeabc15 100644
--- a/tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Html/HtmlCommentsTest.php
@@ -25,14 +25,20 @@ class HtmlCommentsTest extends Functional\AbstractFunctional
         $plainMulti->createText($valueMulti);
 
         $richSingle = new RichText();
-        $richSingle->createTextRun($valueSingle)->getFont()->setBold(true);
+        $font = $richSingle->createTextRun($valueSingle)->getFont();
+        self::assertNotNull($font);
+        $font->setBold(true);
 
         $richMultiSimple = new RichText();
-        $richMultiSimple->createTextRun($valueMulti)->getFont()->setBold(true);
+        $font = $richMultiSimple->createTextRun($valueMulti)->getFont();
+        self::assertNotNull($font);
+        $font->setBold(true);
 
         $richMultiMixed = new RichText();
         $richMultiMixed->createText('I am' . PHP_EOL);
-        $richMultiMixed->createTextRun('multi-line')->getFont()->setBold(true);
+        $font = $richMultiMixed->createTextRun('multi-line')->getFont();
+        self::assertNotNull($font);
+        $font->setBold(true);
         $richMultiMixed->createText(PHP_EOL . 'comment!');
 
         return [
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php
index 9a801015..f9535714 100644
--- a/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataCloneTest.php
@@ -78,14 +78,18 @@ class UnparsedDataCloneTest extends TestCase
         $spreadsheet1 = $reader1->load($resultFilename1);
         unlink($resultFilename1);
         $sheet1c = $spreadsheet1->getSheetByName('Clone');
+        self::assertNotNull($sheet1c);
         $sheet1o = $spreadsheet1->getSheetByName('Original');
+        self::assertNotNull($sheet1o);
 
         $writer->save($resultFilename2);
         $reader2 = new \PhpOffice\PhpSpreadsheet\Reader\Xlsx();
         $spreadsheet2 = $reader2->load($resultFilename2);
         unlink($resultFilename2);
         $sheet2c = $spreadsheet2->getSheetByName('Clone');
+        self::assertNotNull($sheet2c);
         $sheet2o = $spreadsheet2->getSheetByName('Original');
+        self::assertNotNull($sheet2o);
 
         self::assertEquals($spreadsheet1->getSheetCount(), $spreadsheet2->getSheetCount());
         self::assertCount(1, $sheet1c->getDrawingCollection());
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
index 981962bc..1f54a76c 100644
--- a/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/UnparsedDataTest.php
@@ -64,7 +64,7 @@ class UnparsedDataTest extends TestCase
         self::assertNotEmpty($resultVbaProjectRaw, 'vbaProject.bin not found!');
 
         // xl/workbook.xml
-        $xmlWorkbook = simplexml_load_string($resultWorkbookRaw, 'SimpleXMLElement', Settings::getLibXmlLoaderOptions());
+        $xmlWorkbook = simplexml_load_string($resultWorkbookRaw ?: '', 'SimpleXMLElement', Settings::getLibXmlLoaderOptions());
         self::assertNotFalse($xmlWorkbook);
         if (!$xmlWorkbook->workbookProtection) {
             self::fail('workbook.xml/workbookProtection not found!');
@@ -86,7 +86,8 @@ class UnparsedDataTest extends TestCase
 
         // xl/worksheets/sheet1.xml
         self::assertStringContainsString('<mc:AlternateContent', $resultSheet1Raw, 'AlternateContent at sheet1.xml not found!');
-        $xmlWorksheet = simplexml_load_string($resultSheet1Raw, 'SimpleXMLElement', Settings::getLibXmlLoaderOptions());
+        $xmlWorksheet = simplexml_load_string($resultSheet1Raw ?: '', 'SimpleXMLElement', Settings::getLibXmlLoaderOptions());
+        self::assertNotFalse($xmlWorksheet);
         $pageSetupAttributes = $xmlWorksheet->pageSetup->attributes('http://schemas.openxmlformats.org/officeDocument/2006/relationships');
         self::assertTrue(isset($pageSetupAttributes->id), 'sheet1.xml/pageSetup[r:id] not found!');
         if (!$xmlWorksheet->sheetProtection) {
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/WmfTest.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/WmfTest.php
index 35ae742c..b43b1358 100644
--- a/tests/PhpSpreadsheetTests/Writer/Xlsx/WmfTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/WmfTest.php
@@ -3,6 +3,7 @@
 namespace PhpOffice\PhpSpreadsheetTests\Writer\Xlsx;
 
 use PhpOffice\PhpSpreadsheet\Reader\Xlsx;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
 use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
 
 class WmfTest extends AbstractFunctional
@@ -19,6 +20,7 @@ class WmfTest extends AbstractFunctional
         $drawings = $spreadsheet->getActiveSheet()->getDrawingCollection();
         self::assertCount(1, $drawings);
         $drawing = $drawings[0];
+        self::assertInstanceOf(Drawing::class, $drawing);
         self::assertSame('wmf', $drawing->getExtension());
 
         // Save spreadsheet to file and read it back
@@ -26,6 +28,7 @@ class WmfTest extends AbstractFunctional
         $drawings = $reloadedSpreadsheet->getActiveSheet()->getDrawingCollection();
         self::assertCount(1, $drawings);
         $drawing = $drawings[0];
+        self::assertInstanceOf(Drawing::class, $drawing);
         self::assertSame('wmf', $drawing->getExtension());
 
         $spreadsheet->disconnectWorksheets();
diff --git a/tests/data/Calculation/MathTrig/SUMIF.php b/tests/data/Calculation/MathTrig/SUMIF.php
index 3daf6bfd..bb5d6aa1 100644
--- a/tests/data/Calculation/MathTrig/SUMIF.php
+++ b/tests/data/Calculation/MathTrig/SUMIF.php
@@ -23,7 +23,7 @@ return [
         ],
     ],
     [
-        'incomplete', // 10,
+        10, // fixed by PR #2561
         [
             ['"text with quotes"'],
             [2],