Use a more fault-tolerant version of php-parser

src/Psalm/Checker/FileChecker.php

@@ -577,8 +577,16 @@ class FileChecker extends SourceChecker implements StatementsSource
 
             $parser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7, $lexer);
 
+            $error_handler = new \PhpParser\ErrorHandler\Collecting();
+
             /** @var array<int, \PhpParser\Node\Stmt> */
-            $stmts = $parser->parse($file_contents);
+            $stmts = $parser->parse($file_contents, $error_handler);
+
+            if (!$stmts && $error_handler->hasErrors()) {
+                foreach ($error_handler->getErrors() as $error) {
+                    throw $error;
+                }
+            }
         }
 
         if ($parser_cache_directory && $cache_location) {

tests/BadFormatTest.php

@@ -0,0 +1,62 @@
+<?php
+namespace Psalm\Tests;
+
+use PhpParser\ParserFactory;
+use PHPUnit_Framework_TestCase;
+use Psalm\Checker\FileChecker;
+use Psalm\Config;
+use Psalm\Context;
+
+class BadFormatTest extends PHPUnit_Framework_TestCase
+{
+    /** @var \PhpParser\Parser */
+    protected static $parser;
+
+    /** @var TestConfig */
+    protected static $config;
+
+    /** @var \Psalm\Checker\ProjectChecker */
+    protected $project_checker;
+
+    /**
+     * @return void
+     */
+    public static function setUpBeforeClass()
+    {
+        self::$parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
+        self::$config = new TestConfig();
+    }
+
+    /**
+     * @return void
+     */
+    public function setUp()
+    {
+        FileChecker::clearCache();
+        $this->project_checker = new \Psalm\Checker\ProjectChecker();
+        $this->project_checker->setConfig(self::$config);
+    }
+
+    /**
+     * @return void
+     */
+    public function testMissingSemicolon()
+    {
+        $this->project_checker->registerFile(
+            getcwd() . '/somefile.php',
+            '<?php
+        class A {
+            /** @var int|null */
+            protected $hello;
+
+            /** @return void */
+            function foo() {
+                $this->hello = 5
+            }
+        }'
+        );
+
+        $file_checker = new FileChecker(getcwd() . '/somefile.php', $this->project_checker);
+        $file_checker->visitAndAnalyzeMethods();
+    }
+}