Slight Increase in Coverage Reading BIFF8

After breaking up Xls Reader (PR #4118), it is a little easier to identify uncovered code. BIFF8 had no tests involving constant arrays. This PR adds some. Most of the work is in the tests, but some source code is modernized to use things like null coercion.

src/PhpSpreadsheet/Reader/Xls/Color.php

@@ -24,12 +24,6 @@ class Color
             return $palette[$color - 8];
         }
 
-        // default color table
-        if ($version == Xls::XLS_BIFF8) {
-            return Color\BIFF8::lookup($color);
-        }
-
-        // BIFF5
-        return Color\BIFF5::lookup($color);
+        return ($version === Xls::XLS_BIFF8) ? Color\BIFF8::lookup($color) : Color\BIFF5::lookup($color);
     }
 }

src/PhpSpreadsheet/Reader/Xls/ConditionalFormatting.php

@@ -36,20 +36,12 @@ class ConditionalFormatting extends Xls
 
     public static function type(int $type): ?string
     {
-        if (isset(self::$types[$type])) {
-            return self::$types[$type];
-        }
-
-        return null;
+        return self::$types[$type] ?? null;
     }
 
     public static function operator(int $operator): ?string
     {
-        if (isset(self::$operators[$operator])) {
-            return self::$operators[$operator];
-        }
-
-        return null;
+        return self::$operators[$operator] ?? null;
     }
 
     /**

src/PhpSpreadsheet/Reader/Xls/DataValidationHelper.php

@@ -48,29 +48,17 @@ class DataValidationHelper extends Xls
 
     public static function type(int $type): ?string
     {
-        if (isset(self::$types[$type])) {
-            return self::$types[$type];
-        }
-
-        return null;
+        return self::$types[$type] ?? null;
     }
 
     public static function errorStyle(int $errorStyle): ?string
     {
-        if (isset(self::$errorStyles[$errorStyle])) {
-            return self::$errorStyles[$errorStyle];
-        }
-
-        return null;
+        return self::$errorStyles[$errorStyle] ?? null;
     }
 
     public static function operator(int $operator): ?string
     {
-        if (isset(self::$operators[$operator])) {
-            return self::$operators[$operator];
-        }
-
-        return null;
+        return self::$operators[$operator] ?? null;
     }
 
     /**

src/PhpSpreadsheet/Reader/Xls/ListFunctions.php

@@ -44,12 +44,10 @@ class ListFunctions extends Xls
         }
 
         foreach ($xls->sheets as $sheet) {
-            if ($sheet['sheetType'] != 0x00) {
+            if ($sheet['sheetType'] === 0x00) {
                 // 0x00: Worksheet, 0x02: Chart, 0x06: Visual Basic module
-                continue;
+                $worksheetNames[] = $sheet['name'];
             }
-
-            $worksheetNames[] = $sheet['name'];
         }
 
         return $worksheetNames;
@@ -93,7 +91,7 @@ class ListFunctions extends Xls
 
         // Parse the individual sheets
         foreach ($xls->sheets as $sheet) {
-            if ($sheet['sheetType'] != 0x00) {
+            if ($sheet['sheetType'] !== 0x00) {
                 // 0x00: Worksheet
                 // 0x02: Chart
                 // 0x06: Visual Basic module

src/PhpSpreadsheet/Reader/Xls/Style/Border.php

@@ -28,10 +28,6 @@ class Border
 
     public static function lookup(int $index): string
     {
-        if (isset(self::$borderStyleMap[$index])) {
-            return self::$borderStyleMap[$index];
-        }
-
-        return StyleBorder::BORDER_NONE;
+        return self::$borderStyleMap[$index] ?? StyleBorder::BORDER_NONE;
     }
 }

src/PhpSpreadsheet/Reader/Xls/Style/FillPattern.php

@@ -37,10 +37,6 @@ class FillPattern
      */
     public static function lookup(int $index): string
     {
-        if (isset(self::$fillPatternMap[$index])) {
-            return self::$fillPatternMap[$index];
-        }
-
-        return Fill::FILL_NONE;
+        return self::$fillPatternMap[$index] ?? Fill::FILL_NONE;
     }
 }

tests/PhpSpreadsheetTests/Reader/Xls/Biff8CoverTest.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Xls;
+
+use PhpOffice\PhpSpreadsheet\Reader\Xls;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PHPUnit\Framework\TestCase;
+
+class Biff8CoverTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        Date::setExcelCalendar(Date::CALENDAR_WINDOWS_1900);
+    }
+
+    public function testBiff8Coverage(): void
+    {
+        $filename = 'tests/data/Reader/XLS/biff8cover.xls';
+        $reader = new Xls();
+        $spreadsheet = $reader->load($filename);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('=SUM({1;2;3;4;5})', $sheet->getCell('A1')->getValue());
+        self::assertSame(15, $sheet->getCell('A1')->getCalculatedValue());
+        self::assertSame(
+            '=VLOOKUP("hello",'
+            . '{"what",1;"why",TRUE;"hello","there";"when",FALSE}'
+            . ',2,FALSE)',
+            $sheet->getCell('C1')->getValue()
+        );
+        self::assertSame('there', $sheet->getCell('C1')->getCalculatedValue());
+        self::assertSame(2, $sheet->getCell('A3')->getValue());
+        self::assertTrue(
+            $sheet->getStyle('A3')->getFont()->getSuperscript()
+        );
+        self::assertSame('n', $sheet->getCell('B3')->getValue());
+        self::assertTrue(
+            $sheet->getStyle('B3')->getFont()->getSubscript()
+        );
+
+        $spreadsheet->disconnectWorksheets();
+    }
+}