[CI] Add parse test (covers !58)

inc/test/php/ParseTest.php

@@ -0,0 +1,19 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+final class ParseTest extends TestCase {
+    public function testParse(): void {
+        $files = glob("{*.php,**/*.php}", GLOB_BRACE);
+        foreach ($files as $file) {
+            $result = exec("php -l $file");
+            // Check for failure
+            self::assertStringNotContainsStringIgnoringCase("fail", $result);
+            self::assertStringNotContainsStringIgnoringCase("errors parsing", $result);
+            self::assertStringNotContainsStringIgnoringCase("error:", $result);
+            self::assertStringNotContainsStringIgnoringCase("warning:", $result);
+            // Check for success
+            self::assertStringContainsString("No syntax errors detected in ", $result);
+        }
+    }
+}