Fix Phpstan and Scrutinizer Problems

Author: oleibman

src/PhpSpreadsheet/Shared/Trend/Trend.php

@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\Trend;
 
+use PhpOffice\PhpSpreadsheet\Exception as SpreadsheetException;
+
 class Trend
 {
     const TREND_LINEAR = 'Linear';
@@ -46,7 +48,7 @@ class Trend
      */
     private static array $trendCache = [];
 
-    public static function calculate(string $trendType = self::TREND_BEST_FIT, array $yValues = [], array $xValues = [], bool $const = true): mixed
+    public static function calculate(string $trendType = self::TREND_BEST_FIT, array $yValues = [], array $xValues = [], bool $const = true): BestFit
     {
         //    Calculate number of points in each dataset
         $nY = count($yValues);
@@ -57,7 +59,7 @@ public static function calculate(string $trendType = self::TREND_BEST_FIT, array
             $xValues = range(1, $nY);
         } elseif ($nY !== $nX) {
             //    Ensure both arrays of points are the same size
-            trigger_error('Trend(): Number of elements in coordinate arrays do not match.', E_USER_ERROR);
+            throw new SpreadsheetException('Trend(): Number of elements in coordinate arrays do not match.');
         }
 
         $key = md5($trendType . $const . serialize($yValues) . serialize($xValues));
@@ -113,7 +115,7 @@ public static function calculate(string $trendType = self::TREND_BEST_FIT, array
 
                 return $bestFit[$bestFitType];
             default:
-                return false;
+                throw new SpreadsheetException("Unknown trend type $trendType");
         }
     }
 }

tests/PhpSpreadsheetTests/Shared/Trend/BestFitTest.php

@@ -63,10 +63,26 @@ public function testBestFit(): void
 
         try {
             $type = Trend::TREND_BEST_FIT;
-            $result = Trend::calculate($type, $yValues, $xValues);
+            Trend::calculate($type, $yValues, [0, 1, 2]);
+            self::fail('should have failed - mismatched number of elements');
+        } catch (SpreadsheetException $e) {
+            self::assertStringContainsString('Number of elements', $e->getMessage());
+        }
+
+        try {
+            $type = Trend::TREND_BEST_FIT;
+            Trend::calculate($type, $yValues, $xValues);
             self::fail('should have failed - TREND_BEST_FIT includes polynomials which are not implemented yet');
         } catch (SpreadsheetException $e) {
             self::assertStringContainsString('not yet implemented', $e->getMessage());
         }
+
+        try {
+            $type = 'unknown';
+            Trend::calculate($type, $yValues, $xValues);
+            self::fail('should have failed - invalid trend type');
+        } catch (SpreadsheetException $e) {
+            self::assertStringContainsString('Unknown trend type', $e->getMessage());
+        }
     }
 }