Patch tests to suppress root commnts

tests/cases/TestTreeConstructor.php

@@ -28,12 +28,12 @@ class TestTreeConstructor extends \PHPUnit\Framework\TestCase {
     protected $depth;
 
     /** @dataProvider provideStandardTreeTests */
-    public function testStandardTreeTests(string $data, array $exp, array $errors, $fragment, ?bool $scripted): void {
-        if ($scripted) {
-            $this->markTestIncomplete("Scripting is not supported");
-        } elseif ($fragment) {
-            $this->markTestSkipped("Fragment tests still to be implemented");
+    public function testStandardTreeTests(string $data, array $exp, array $errors, $fragment): void {
+        if ($fragment) {
+            $this->markTestIncomplete("Fragment tests still to be implemented");
         }
+        // certain tests need to be patched to ignore unavoidable limitations of PHP's DOM
+        $exp = $this->patchTest($data, $fragment, $exp);
         // convert parse error constants into standard symbols in specification
         $errorMap = array_map(function($str) {
             return strtolower(str_replace("_", "-", $str));
@@ -71,6 +71,14 @@ class TestTreeConstructor extends \PHPUnit\Framework\TestCase {
         // TODO: evaluate errors
     }
 
+    protected function patchTest(string $data, $fragment, array $exp): array {
+        if (strpos($exp[0], "| <!--") === 0) {
+            // comments before the DOCTYPE are silently dropped by the PHP DOM
+            array_shift($exp);
+        }
+        return $exp;
+    }
+
     protected function push(string $data): void {
         $this->out[] = "| ".str_repeat("  ", $this->depth).$data;
     }
@@ -196,7 +204,10 @@ class TestTreeConstructor extends \PHPUnit\Framework\TestCase {
                         assert(preg_match('/^[^#]/', $lines[$l]) === 1, new \Exception("Test $file #$index contains unrecognized data after document at line ".($l + 1)));
                         $exp[] = $lines[$l];
                     }
-                    yield "$file #$index (line $pos)" => [$data, $exp, $errors, $fragment, $script];
+                    if (!$script) {
+                        // scripting-dependent tests are skipped entirely since we will not support scripting
+                        yield "$file #$index (line $pos)" => [$data, $exp, $errors, $fragment];
+                    }
                     $l++;
                     $index++;
                 }