fix: checking existing argument with equal sign

tests/.snapshots/success.txt

@@ -1212,6 +1212,14 @@
    PASS  Tests\Unit\Overrides\ThrowableBuilder
   ✓ collision editor can be added to the stack trace
 
+   PASS  Tests\Unit\Plugins\Concerns\HandleArguments
+  ✓ method hasArgument with ('--long-argument', true)
+  ✓ method hasArgument with ('-a', true)
+  ✓ method hasArgument with ('--with-equal-sign', true)
+  ✓ method hasArgument with ('someValue', true)
+  ✓ method hasArgument with ('--a', false)
+  ✓ method hasArgument with ('--undefined-argument', false)
+
    PASS  Tests\Unit\Plugins\Environment
   ✓ environment is set to CI when --ci option is used
   ✓ environment is set to Local when --ci option is not used
@@ -1364,4 +1372,4 @@
    WARN  Tests\Visual\Version
   - visual snapshot of help command output
 
-  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 19 skipped, 970 passed (2296 assertions)
+  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 19 skipped, 976 passed (2302 assertions)

tests/Unit/Plugins/Concerns/HandleArguments.php

@@ -0,0 +1,26 @@
+<?php
+
+use Pest\Plugins\Concerns\HandleArguments;
+
+test('method hasArgument', function (string $argument, bool $expectedResult) {
+    $obj = new class
+    {
+        use HandleArguments;
+    };
+
+    $arguments = [
+        '--long-argument',
+        'someValue',
+        '-a',
+        '--with-equal-sign=1337',
+    ];
+
+    expect($obj->hasArgument($argument, $arguments))->toBe($expectedResult);
+})->with([
+    ['--long-argument', true],
+    ['-a', true],
+    ['--with-equal-sign', true],
+    ['someValue', true],
+    ['--a', false],
+    ['--undefined-argument', false],
+]);

tests/Visual/Parallel.php

@@ -16,7 +16,7 @@ $run = function () {
 
 test('parallel', function () use ($run) {
     expect($run('--exclude-group=integration'))
-        ->toContain('Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 15 skipped, 957 passed (2277 assertions)')
+        ->toContain('Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 15 skipped, 963 passed (2283 assertions)')
         ->toContain('Parallel: 3 processes');
 })->skipOnWindows();