Smaller diffs

Author: ondrejmirtes

.github/scripts/diffPrefixes.php

@@ -1,5 +1,6 @@
 <?php declare(strict_types = 1);
 
+use Nette\Utils\Strings;
 use SebastianBergmann\Diff\Differ;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
@@ -20,7 +21,7 @@
 }
 
 $diffLines = explode("\n", file_get_contents($diffFile));
-$differ = new Differ(new \SebastianBergmann\Diff\Output\UnifiedDiffOutputBuilder(''));
+$differ = new Differ(new \SebastianBergmann\Diff\Output\UnifiedDiffOutputBuilder('', true));
 $isDifferent = false;
 foreach ($diffLines as $diffLine) {
 	$operation = $diffLine[0];
@@ -48,7 +49,20 @@
 	$isDifferent = true;
 
 	echo "$path:\n";
-	foreach (explode("\n", $stringDiff) as $line) {
+	$startLine = 1;
+	$startContext = 1;
+	foreach (explode("\n", $stringDiff) as $i => $line) {
+		$matches = Strings::match($line, '/^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@/');
+		if ($matches !== null) {
+			$startLine = (int) $matches[1];
+			$startContext = (int) $matches[2];
+			continue;
+		}
+
+		if ($lineNumber < $startLine || $lineNumber > ($startLine + $startContext)) {
+			continue;
+		}
+
 		if (str_starts_with($line, '+')) {
 			echo "\033[32m$line\033[0m\n";
 		} elseif (str_starts_with($line, '-')) {