From 42553740e4c73baa0caa4f5e9182718e4c8024e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20M=C3=BCller?= <marcel-mueller@gmx.de>
Date: Sun, 16 Aug 2026 16:11:27 +0200
Subject: [PATCH] chore: Add junit-analyzer to check the phpunit performance
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Assisted-by: ClaudeCode:claude-opus-5
Signed-off-by: Marcel Müller <marcel-mueller@gmx.de>
---
 .github/workflows/phpunit-sqlite.yml |  10 ++
 tests/junit-analyzer.php             | 139 +++++++++++++++++++++++++++
 2 files changed, 149 insertions(+)
 create mode 100644 tests/junit-analyzer.php

diff --git a/.github/workflows/phpunit-sqlite.yml b/.github/workflows/phpunit-sqlite.yml
index c7572e91ae5..c623cce3fb0 100644
--- a/.github/workflows/phpunit-sqlite.yml
+++ b/.github/workflows/phpunit-sqlite.yml
@@ -125,6 +125,16 @@ jobs:
       - name: PHPUnit database tests
         run: composer run test:db -- --log-junit junit.xml
 
+      - name: Slowest tests
+        if: always()
+        continue-on-error: true
+        run: |
+          {
+            echo '```'
+            php tests/junit-analyzer.php junit.xml 30
+            echo '```'
+          } | tee -a "${GITHUB_STEP_SUMMARY:-/dev/null}"
+
       - name: Print logs
         if: always()
         run: |
diff --git a/tests/junit-analyzer.php b/tests/junit-analyzer.php
new file mode 100644
index 00000000000..0580d5e62e8
--- /dev/null
+++ b/tests/junit-analyzer.php
@@ -0,0 +1,139 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+/**
+ * Analyse a PHPUnit JUnit log: slowest tests, slowest classes, and whether the
+ * suite degrades over execution order.
+ *
+ * Usage: php tests/junit-analyzer.php [junit.xml] [topN]
+ *
+ * The bucket table splits the run into equal chunks of execution order. A rising
+ * median means the suite itself degrades (accumulated DB rows, leaked memory);
+ * a flat median with rising sum/max means a few slow tests happen to run late.
+ */
+
+const BUCKETS = 10;
+
+$file = $argv[1] ?? 'junit.xml';
+$topCount = (int)($argv[2] ?? 30);
+
+if (!is_readable($file)) {
+	fwrite(STDERR, "cannot read $file\n");
+	exit(1);
+}
+
+libxml_use_internal_errors(true);
+
+$reader = new XMLReader();
+if (!$reader->open($file)) {
+	fwrite(STDERR, "cannot open $file\n");
+	exit(1);
+}
+
+/** @var list<array{class: string, name: string, duration: float}> $tests in execution order */
+$tests = [];
+while ($reader->read()) {
+	if ($reader->nodeType !== XMLReader::ELEMENT || $reader->name !== 'testcase') {
+		continue;
+	}
+	$tests[] = [
+		'class' => $reader->getAttribute('class') ?: '(none)',
+		'name' => (string)$reader->getAttribute('name'),
+		'duration' => (float)$reader->getAttribute('time'),
+	];
+}
+$reader->close();
+
+$testCount = count($tests);
+if ($testCount === 0) {
+	$error = libxml_get_errors()[0] ?? null;
+	fwrite(STDERR, "no testcase elements found in $file"
+		. ($error !== null ? ': ' . trim($error->message) : '') . "\n");
+	exit(1);
+}
+
+$totalDuration = array_sum(array_column($tests, 'duration'));
+printf("%d tests, %.1fs total (%.1f min)\n\n", $testCount, $totalDuration, $totalDuration / 60);
+
+if ($totalDuration <= 0) {
+	fwrite(STDERR, "no timing data to rank\n");
+	exit(0);
+}
+
+printf("Execution order, %d buckets (are later tests slower?)\n", BUCKETS);
+echo "  bucket        tests    sum(s)   mean(ms)   median(ms)    max(s)  cum%\n";
+
+$durationSoFar = 0.0;
+for ($bucket = 0; $bucket < BUCKETS; $bucket++) {
+	$from = (int)floor($testCount * $bucket / BUCKETS);
+	$to = (int)floor($testCount * ($bucket + 1) / BUCKETS);
+
+	$durations = array_column(array_slice($tests, $from, $to - $from), 'duration');
+	sort($durations);
+	$inBucket = count($durations);
+	$bucketDuration = array_sum($durations);
+	$durationSoFar += $bucketDuration;
+
+	printf(
+		"  %3d-%3d%%  %7d %9.1f %10.2f %12.2f %9.2f %5.1f%%\n",
+		$bucket * (100 / BUCKETS),
+		($bucket + 1) * (100 / BUCKETS),
+		$inBucket,
+		$bucketDuration,
+		$inBucket ? $bucketDuration / $inBucket * 1000 : 0,
+		$inBucket ? $durations[intdiv($inBucket, 2)] * 1000 : 0,
+		$inBucket ? max($durations) : 0,
+		$durationSoFar / $totalDuration * 100,
+	);
+}
+
+$slowestFirst = $tests;
+usort($slowestFirst, static fn (array $a, array $b): int => $b['duration'] <=> $a['duration']);
+
+printf("\nTop %d slowest tests\n", $topCount);
+foreach (array_slice($slowestFirst, 0, $topCount) as $test) {
+	printf("  %8.2fs  %s::%s\n", $test['duration'], $test['class'], $test['name']);
+}
+
+/** @var array<string, array{duration: float, tests: int}> $classes */
+$classes = [];
+foreach ($tests as $test) {
+	$classes[$test['class']] ??= ['duration' => 0.0, 'tests' => 0];
+	$classes[$test['class']]['duration'] += $test['duration'];
+	$classes[$test['class']]['tests']++;
+}
+uasort($classes, static fn (array $a, array $b): int => $b['duration'] <=> $a['duration']);
+
+printf("\nTop %d slowest classes (sum of its tests)\n", $topCount);
+printf("  %9s %7s %10s  %s\n", 'sum', 'tests', 'mean(ms)', 'class');
+foreach (array_slice($classes, 0, $topCount, true) as $class => $stats) {
+	printf(
+		"  %8.2fs %7d %10.2f  %s\n",
+		$stats['duration'],
+		$stats['tests'],
+		$stats['duration'] / $stats['tests'] * 1000,
+		$class,
+	);
+}
+
+// How top-heavy is the run? A handful of tests dominating reads very differently
+// from the cost being spread evenly.
+$durationSoFar = 0.0;
+$testsInHalfTheRuntime = 0;
+foreach ($slowestFirst as $test) {
+	$durationSoFar += $test['duration'];
+	$testsInHalfTheRuntime++;
+	if ($durationSoFar >= $totalDuration / 2) {
+		break;
+	}
+}
+printf(
+	"\nThe slowest %d tests (%.1f%% of tests) account for 50%% of the runtime.\n",
+	$testsInHalfTheRuntime,
+	$testsInHalfTheRuntime / $testCount * 100,
+);