Add code exists check

app/config.php

@@ -63,6 +63,7 @@
 use PhpSchool\PhpWorkshop\Utils\RequestRenderer;
 use PhpSchool\PhpWorkshop\WorkshopType;
 use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
 use PhpSchool\PhpWorkshop\Check\FunctionRequirementsCheck;
 use PhpSchool\PhpWorkshop\Check\PhpLintCheck;
 use PhpSchool\PhpWorkshop\Command\CreditsCommand;
@@ -109,6 +110,7 @@
     CheckRepository::class => function (ContainerInterface $c) {
         return new CheckRepository([
             $c->get(FileExistsCheck::class),
+            $c->get(CodeExistsCheck::class),
             $c->get(PhpLintCheck::class),
             $c->get(CodeParseCheck::class),
             $c->get(ComposerCheck::class),
@@ -239,6 +241,9 @@
     //checks
     FileExistsCheck::class              => create(),
     PhpLintCheck::class                 => create(),
+    CodeExistsCheck::class              => function (ContainerInterface $c) {
+        return new CodeExistsCheck($c->get(Parser::class));
+    },
     CodeParseCheck::class               => function (ContainerInterface $c) {
         return new CodeParseCheck($c->get(Parser::class));
     },

src/Check/CodeExistsCheck.php

@@ -0,0 +1,85 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpSchool\PhpWorkshop\Check;
+
+use PhpParser\Error;
+use PhpParser\ErrorHandler;
+use PhpParser\Node\Stmt\InlineHTML;
+use PhpParser\NodeFinder;
+use PhpParser\Parser;
+use PhpSchool\PhpWorkshop\Exercise\ExerciseInterface;
+use PhpSchool\PhpWorkshop\Exercise\ExerciseType;
+use PhpSchool\PhpWorkshop\Input\Input;
+use PhpSchool\PhpWorkshop\Result\Failure;
+use PhpSchool\PhpWorkshop\Result\ResultInterface;
+use PhpSchool\PhpWorkshop\Result\Success;
+
+class CodeExistsCheck implements SimpleCheckInterface
+{
+    /**
+     * @var Parser
+     */
+    private $parser;
+
+    public function __construct(Parser $parser)
+    {
+        $this->parser = $parser;
+    }
+
+    public function getName(): string
+    {
+        return 'Code Exists Check';
+    }
+
+    /**
+     * Check solution provided contains code
+     * Note: We don't care if it's valid code at this point
+     */
+    public function check(ExerciseInterface $exercise, Input $input): ResultInterface
+    {
+        $noopHandler = new class implements ErrorHandler {
+            public function handleError(Error $error): void
+            {
+            }
+        };
+
+        $code = (string) file_get_contents($input->getRequiredArgument('program'));
+        $statements = $this->parser->parse($code, $noopHandler);
+
+        $empty = null === $statements || empty($statements);
+
+        if (!$empty) {
+            $openingTag = is_array($statements) && count($statements) === 1 ? $statements[0] : null;
+            $empty = $openingTag instanceof InlineHTML ? in_array($openingTag->value, ['<?php', '<?']) : false;
+        }
+
+        if ($empty) {
+            return Failure::fromCheckAndReason($this, 'No code was found');
+        }
+
+        return Success::fromCheck($this);
+    }
+
+    /**
+     * This check can run on any exercise type.
+     */
+    public function canRun(ExerciseType $exerciseType): bool
+    {
+        return in_array($exerciseType->getValue(), [ExerciseType::CGI, ExerciseType::CLI], true);
+    }
+
+    public function getExerciseInterface(): string
+    {
+        return ExerciseInterface::class;
+    }
+
+    /**
+     * This check must run before executing the solution because all solutions require code
+     */
+    public function getPosition(): string
+    {
+        return SimpleCheckInterface::CHECK_BEFORE;
+    }
+}

src/ExerciseRunner/CgiRunner.php

@@ -5,6 +5,7 @@
 namespace PhpSchool\PhpWorkshop\ExerciseRunner;
 
 use GuzzleHttp\Psr7\Message;
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
 use PhpSchool\PhpWorkshop\Check\CodeParseCheck;
 use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
 use PhpSchool\PhpWorkshop\Check\PhpLintCheck;
@@ -55,6 +56,7 @@ class CgiRunner implements ExerciseRunnerInterface
      */
     private static $requiredChecks = [
         FileExistsCheck::class,
+        CodeExistsCheck::class,
         PhpLintCheck::class,
         CodeParseCheck::class,
     ];

src/ExerciseRunner/CliRunner.php

@@ -4,6 +4,7 @@
 
 namespace PhpSchool\PhpWorkshop\ExerciseRunner;
 
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
 use PhpSchool\PhpWorkshop\Check\CodeParseCheck;
 use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
 use PhpSchool\PhpWorkshop\Check\PhpLintCheck;
@@ -50,6 +51,7 @@ class CliRunner implements ExerciseRunnerInterface
      */
     private static $requiredChecks = [
         FileExistsCheck::class,
+        CodeExistsCheck::class,
         PhpLintCheck::class,
         CodeParseCheck::class,
     ];

test/Check/CodeExistsCheckTest.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace PhpSchool\PhpWorkshopTest\Check;
+
+use PhpParser\ParserFactory;
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
+use PhpSchool\PhpWorkshop\Check\SimpleCheckInterface;
+use PhpSchool\PhpWorkshop\Exercise\ExerciseType;
+use PhpSchool\PhpWorkshop\Input\Input;
+use PHPUnit\Framework\TestCase;
+use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
+use PhpSchool\PhpWorkshop\Exercise\ExerciseInterface;
+use PhpSchool\PhpWorkshop\Result\Failure;
+use PhpSchool\PhpWorkshop\Result\Success;
+
+class CodeExistsCheckTest extends TestCase
+{
+    /**
+     * @var string
+     */
+    private $testDir;
+
+    /**
+     * @var FileExistsCheck
+     */
+    private $check;
+
+    /**
+     * @var ExerciseInterface
+     */
+    private $exercise;
+
+    public function setUp(): void
+    {
+        $this->testDir = sprintf(
+            '%s/%s/%s',
+            str_replace('\\', '/', sys_get_temp_dir()),
+            basename(str_replace('\\', '/', get_class($this))),
+            $this->getName()
+        );
+
+        mkdir($this->testDir, 0777, true);
+        $this->check = new CodeExistsCheck((new ParserFactory())->create(ParserFactory::PREFER_PHP7));
+        $this->exercise = $this->createMock(ExerciseInterface::class);
+        $this->assertEquals('Code Exists Check', $this->check->getName());
+        $this->assertEquals(ExerciseInterface::class, $this->check->getExerciseInterface());
+        $this->assertEquals(SimpleCheckInterface::CHECK_BEFORE, $this->check->getPosition());
+
+        $this->assertTrue($this->check->canRun(ExerciseType::CGI()));
+        $this->assertTrue($this->check->canRun(ExerciseType::CLI()));
+
+        $this->file = sprintf('%s/submission.php', $this->testDir);
+        touch($this->file);
+    }
+
+    public function testSuccess(): void
+    {
+        file_put_contents($this->file, '<?php echo "Hello World";');
+
+        $this->assertInstanceOf(
+            Success::class,
+            $this->check->check($this->exercise, new Input('app', ['program' => $this->file]))
+        );
+    }
+
+    public function testFailure(): void
+    {
+        file_put_contents($this->file, '<?php');
+
+        $failure = $this->check->check($this->exercise, new Input('app', ['program' => $this->file]));
+
+        $this->assertInstanceOf(Failure::class, $failure);
+        $this->assertEquals('No code was found', $failure->getReason());
+    }
+
+    public function tearDown(): void
+    {
+        unlink($this->file);
+        rmdir($this->testDir);
+    }
+}

test/ExerciseRunner/CgiRunnerTest.php

@@ -4,6 +4,7 @@
 
 use Colors\Color;
 use GuzzleHttp\Psr7\Request;
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
 use PhpSchool\Terminal\Terminal;
 use PhpSchool\PhpWorkshop\Check\CodeParseCheck;
 use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
@@ -53,6 +54,7 @@ public function testRequiredChecks(): void
     {
         $requiredChecks = [
             FileExistsCheck::class,
+            CodeExistsCheck::class,
             PhpLintCheck::class,
             CodeParseCheck::class,
         ];

test/ExerciseRunner/CliRunnerTest.php

@@ -3,6 +3,7 @@
 namespace PhpSchool\PhpWorkshopTest\ExerciseRunner;
 
 use Colors\Color;
+use PhpSchool\PhpWorkshop\Check\CodeExistsCheck;
 use PhpSchool\Terminal\Terminal;
 use PhpSchool\PhpWorkshop\Check\CodeParseCheck;
 use PhpSchool\PhpWorkshop\Check\FileExistsCheck;
@@ -54,6 +55,7 @@ public function testRequiredChecks(): void
     {
         $requiredChecks = [
             FileExistsCheck::class,
+            CodeExistsCheck::class,
             PhpLintCheck::class,
             CodeParseCheck::class,
         ];