Additional unit tests

tests/PhpSpreadsheetTests/Calculation/CalculationTest.php

@@ -180,6 +180,18 @@ class CalculationTest extends TestCase
         self::assertEquals('9', $cell3->getCalculatedValue());
     }
 
+    public function testCellWithStringNumeric(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $workSheet = $spreadsheet->getActiveSheet();
+        $cell1 = $workSheet->getCell('A1');
+        $cell1->setValue('+2.5');
+        $cell2 = $workSheet->getCell('B1');
+        $cell2->setValue('=100*A1');
+
+        self::assertSame(250.0, $cell2->getCalculatedValue());
+    }
+
     public function testCellWithStringFraction(): void
     {
         $spreadsheet = new Spreadsheet();

tests/PhpSpreadsheetTests/Calculation/Engine/FormattedNumberTest.php

@@ -7,6 +7,26 @@ use PHPUnit\Framework\TestCase;
 
 class FormattedNumberTest extends TestCase
 {
+    /**
+     * @dataProvider providerNumbers
+     *
+     * @param mixed $expected
+     */
+    public function testNumber($expected, string $value): void
+    {
+        FormattedNumber::convertToNumberIfFormatted($value);
+        self::assertSame($expected, $value);
+    }
+
+    public function providerNumbers(): array
+    {
+        return [
+            [-12.5, '-12.5'],
+            [-125.0, '-1.25e2'],
+            [0.125, '12.5%'],
+        ];
+    }
+
     /**
      * @dataProvider providerFractions
      */