Unit test some basic arra-formula chaining (#2599)

tests/PhpSpreadsheetTests/Calculation/ArrayFormulaTest.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Calculation;
+
+use PhpOffice\PhpSpreadsheet\Calculation\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PHPUnit\Framework\TestCase;
+
+class ArrayFormulaTest extends TestCase
+{
+    /**
+     * @var string
+     */
+    private $compatibilityMode;
+
+    /**
+     * @var string
+     */
+    private $locale;
+
+    protected function setUp(): void
+    {
+        $this->compatibilityMode = Functions::getCompatibilityMode();
+        $calculation = Calculation::getInstance();
+        $this->locale = $calculation->getLocale();
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
+    }
+
+    protected function tearDown(): void
+    {
+        Functions::setCompatibilityMode($this->compatibilityMode);
+        $calculation = Calculation::getInstance();
+        $calculation->setLocale($this->locale);
+    }
+
+    /**
+     * @dataProvider providerArrayFormulae
+     *
+     * @param mixed $expectedResult
+     */
+    public function testArrayFormula(string $formula, $expectedResult): void
+    {
+        $result = Calculation::getInstance()->_calculateFormulaValue($formula);
+        self::assertEquals($expectedResult, $result);
+    }
+
+    public function providerArrayFormulae(): array
+    {
+        return [
+            [
+                '=MAX(ABS({-3, 4, -2; 6, -3, -12}))',
+                12,
+            ],
+            [
+                '=SUM(SEQUENCE(3,3,0,1))',
+                36,
+            ],
+        ];
+    }
+}