AbstractArrayDeclarationSniff::getActualArrayKey(): add extra tests

Author: jrfnl

Tests/AbstractSniffs/AbstractArrayDeclaration/GetActualArrayKeyTest.inc

@@ -136,3 +136,13 @@ $\{abc}
 EOD
               => 3,
 ];
+
+/* testStringLiteralsWithNumbers */
+$validStringKeys = array(
+    '_1'  => 'value1',
+    '_2'  => 'value2',
+    '3_'  => 'value3',
+    '4_'  => 'value4',
+    '_5_' => 'value5',
+    '_6_' => 'value6',
+);

Tests/AbstractSniffs/AbstractArrayDeclaration/GetActualArrayKeyTest.php

@@ -138,4 +138,40 @@ public function testGetActualArrayKeyFromHeredocWithEscapedVarInKey()
             );
         }
     }
+
+    /**
+     * Test retrieving the actual array key when string keys look like numeric literals with underscores.
+     *
+     * @return void
+     */
+    public function testStringLiteralsWithNumbers()
+    {
+        $testObj         = new ArrayDeclarationSniffTestDouble();
+        $testObj->tokens = self::$phpcsFile->getTokens();
+
+        $stackPtr   = $this->getTargetToken('/* testStringLiteralsWithNumbers */', [\T_ARRAY, \T_OPEN_SHORT_ARRAY]);
+        $arrayItems = PassedParameters::getParameters(self::$phpcsFile, $stackPtr);
+
+        $expected = [
+            1 => '_1',
+            2 => '_2',
+            3 => '3_',
+            4 => '4_',
+            5 => '_5_',
+            6 => '_6_',
+        ];
+
+        $this->assertCount(\count($expected), $arrayItems);
+
+        foreach ($arrayItems as $itemNr => $arrayItem) {
+            $arrowPtr = Arrays::getDoubleArrowPtr(self::$phpcsFile, $arrayItem['start'], $arrayItem['end']);
+            $result   = $testObj->getActualArrayKey(self::$phpcsFile, $arrayItem['start'], ($arrowPtr - 1));
+            $this->assertSame(
+                $expected[$itemNr],
+                $result,
+                'Failed: actual key ' . \var_export($result, true) . ' is not the same as the expected key '
+                    . \var_export($expected[$itemNr], true) . ' for item number ' . $itemNr
+            );
+        }
+    }
 }