Fix Rclone::check to return false on differences instead of throwing

src/Rclone.php

@@ -8,6 +8,7 @@
 use JsonException;
 use RuntimeException;
 use Symfony\Component\Process\Process;
+use Verseles\Flyclone\Exception\SyntaxErrorException;
 use Verseles\Flyclone\Providers\LocalProvider;
 use Verseles\Flyclone\Providers\Provider;
 
@@ -1040,13 +1041,28 @@
      * @param array         $flags       Additional flags.
      * @param callable|null $onProgress  Optional progress callback.
      *
-     * @return bool True if check succeeds.
+     * @return bool True if check succeeds (files match), false if differences found.
+     * @throws Exception\SyntaxErrorException If a syntax or usage error occurs.
      */
     public function check(string $source_path, string $dest_path, array $flags = [], ?callable $onProgress = null): bool
     {
-        $this->directTwinRun('check', $source_path, $dest_path, $flags, $onProgress);
+        try {
+            $this->directTwinRun('check', $source_path, $dest_path, $flags, $onProgress);
 
-        return true;
+            return true;
+        } catch (SyntaxErrorException $e) {
+            // Exit code 1 can mean differences found or syntax error.
+            // We check the output to distinguish.
+            $message = $e->getMessage();
+
+            // If it looks like a syntax error ("Error: ...") re-throw
+            if (str_contains($message, 'Error: ')) {
+                throw $e;
+            }
+
+            // Otherwise assume differences found
+            return false;
+        }
     }
 
     /**
@@ -1342,4 +1358,17 @@
     {
         $this->right_side = $right_side;
     }
+
+    /**
+     * Set the ProcessManager instance to use.
+     * Useful for testing or custom process management.
+     *
+     * @param ProcessManager $processManager The ProcessManager instance.
+     */
+    public function setProcessManager(ProcessManager $processManager): self
+    {
+        $this->processManager = $processManager;
+
+        return $this;
+    }
 }

tests/Unit/CheckCommandTest.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Verseles\Flyclone\Test\Unit;
+
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use Symfony\Component\Process\Process;
+use Verseles\Flyclone\Exception\SyntaxErrorException;
+use Verseles\Flyclone\ProcessManager;
+use Verseles\Flyclone\Providers\LocalProvider;
+use Verseles\Flyclone\Rclone;
+
+class CheckCommandTest extends TestCase
+{
+    public function testCheckReturnsFalseOnDifference(): void
+    {
+        $local = new LocalProvider('test');
+        $rclone = new Rclone($local);
+
+        $mockPm = $this->createMock(ProcessManager::class);
+        $rclone->setProcessManager($mockPm);
+
+        $previous = new RuntimeException("Process failed");
+        $syntaxError = new SyntaxErrorException($previous, "2 matching files\n1 differences found", 1);
+
+        $mockPm->method('run')->willThrowException($syntaxError);
+
+        $result = $rclone->check('/source', '/dest');
+
+        $this->assertFalse($result, 'check() should return false when differences are found');
+    }
+
+    public function testCheckThrowsOnActualSyntaxError(): void
+    {
+        $local = new LocalProvider('test');
+        $rclone = new Rclone($local);
+
+        $mockPm = $this->createMock(ProcessManager::class);
+        $rclone->setProcessManager($mockPm);
+
+        $previous = new RuntimeException("Process failed");
+        $syntaxError = new SyntaxErrorException($previous, "Error: unknown flag: --invalid", 1);
+
+        $mockPm->method('run')->willThrowException($syntaxError);
+
+        $this->expectException(SyntaxErrorException::class);
+        $this->expectExceptionMessage("Error: unknown flag: --invalid");
+
+        $rclone->check('/source', '/dest');
+    }
+
+    public function testCheckReturnsTrueOnSuccess(): void
+    {
+        $local = new LocalProvider('test');
+        $rclone = new Rclone($local);
+
+        $mockPm = $this->createMock(ProcessManager::class);
+        $rclone->setProcessManager($mockPm);
+
+        // Mock success process
+        $process = $this->createMock(Process::class);
+        $process->method('getOutput')->willReturn('');
+
+        $mockPm->method('run')->willReturn($process);
+
+        $result = $rclone->check('/source', '/dest');
+
+        $this->assertTrue($result, 'check() should return true when no differences found');
+    }
+}