add support to php 7.4

Author: vitorccs

README.md

@@ -11,7 +11,7 @@ The memory usage is optimized in this project by retrieving small chunks of resu
 This project is using some of Laravel-Excel design principles because it is both a solid work and a reference, and by doing that, it also reduces the learning curve and adoption to this library.
 
 # Requirements
-* PHP >= 8.0
+* PHP >= 7.4
 * Laravel >= 6.x
 
 # Installation

composer.json

@@ -15,7 +15,7 @@
         }
     ],
     "require": {
-        "php": ">=8.0"
+        "php": ">=7.4"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5",

src/Services/Writer.php

@@ -102,7 +102,7 @@ private function iterateRows(object   $exportable,
      * @param mixed $row
      * @return array
      */
-    private function normalizeRow(mixed $row): array
+    private function normalizeRow($row): array
     {
         if ($row instanceof Model) {
             $row = ModelHelper::toArrayValues($row);
@@ -137,7 +137,7 @@ private function applyFormatting(array $row,
     /**
      * @throws InvalidCellValueException
      */
-    private function formatCellValue(mixed $value,
+    private function formatCellValue($value,
                                      array $formats,
                                      int   $rowIndex,
                                      int   $columnIndex): string

tests/Services/ExportableServiceTest.php

@@ -170,7 +170,12 @@ private function getExportMock(string $abstractClass, int $limit = 5)
     {
         $mock = $this->getMockForAbstractClass(
             $abstractClass,
-            mockedMethods: ['limit']
+            [],
+            '',
+            true,
+            true,
+            true,
+            ['limit']
         );
 
         $mock->method('limit')