/*

* This file is part of Notepad Next.

* Copyright 2026 NotepadAI contributors

*

* Notepad Next is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*/

#include <QtTest>

#include <QElapsedTimer>

#include "GitDiffParser.h"

class TestGitDiffParser : public QObject

{

Q_OBJECT

private slots:

void empty_returnsEmpty();

void singleHunk_textAndStats();

void crlf_normalizedOut();

void binaryMarker_setsFlag();

void noNewlineMarker_classified();

void multipleFiles_allFileHeadersCounted();

void perf_5kLineDiff_under60ms();

};

void TestGitDiffParser::empty_returnsEmpty()

{

auto r = GitDiffParser::parse(QByteArray());

QCOMPARE(r.texts.size(), 0);

QCOMPARE(r.addedCount, 0);

QCOMPARE(r.deletedCount, 0);

QVERIFY(!r.isBinary);

}

void TestGitDiffParser::singleHunk_textAndStats()

{

const QByteArray diff =

"diff --git a/foo.cpp b/foo.cpp\n"

"index 1234567..89abcde 100644\n"

"--- a/foo.cpp\n"

"+++ b/foo.cpp\n"

"@@ -1,3 +1,4 @@\n"

" keep1\n"

"-removed\n"

"+added1\n"

"+added2\n"

" keep2\n";

auto r = GitDiffParser::parse(diff);

QCOMPARE(r.addedCount, 2);

QCOMPARE(r.deletedCount, 1);

QVERIFY(!r.isBinary);

QVERIFY(r.texts.size() >= 8); // headers + 5 body lines

QCOMPARE(r.texts.size(), r.kinds.size());

QCOMPARE(r.texts.size(), r.oldLn.size());

QCOMPARE(r.texts.size(), r.newLn.size());

}

void TestGitDiffParser::crlf_normalizedOut()

{

const QByteArray diff =

"@@ -1,1 +1,2 @@\r\n"

" keep\r\n"

"+new\r\n";

auto r = GitDiffParser::parse(diff);

QCOMPARE(r.addedCount, 1);

// The text fields should not contain the trailing CR.

for (const QByteArray &t : r.texts) {

QVERIFY2(!t.endsWith('\r'),

("CR survived in payload: " + t).constData());

}

}

void TestGitDiffParser::binaryMarker_setsFlag()

{

const QByteArray diff =

"diff --git a/img.png b/img.png\n"

"Binary files a/img.png and b/img.png differ\n";

auto r = GitDiffParser::parse(diff);

QVERIFY(r.isBinary);

}

void TestGitDiffParser::noNewlineMarker_classified()

{

const QByteArray diff =

"@@ -1,1 +1,1 @@\n"

"-old\n"

"\\ No newline at end of file\n"

"+new\n";

auto r = GitDiffParser::parse(diff);

bool sawNoNewline = false;

for (auto k : r.kinds) {

if (k == GitDiffParser::LineKind::NoNewline) {

sawNoNewline = true;

break;

}

}

QVERIFY(sawNoNewline);

}

void TestGitDiffParser::multipleFiles_allFileHeadersCounted()

{

const QByteArray diff =

"diff --git a/a.cpp b/a.cpp\n"

"--- a/a.cpp\n"

"+++ b/a.cpp\n"

"@@ -1,1 +1,1 @@\n"

"-x\n"

"+y\n"

"diff --git a/b.cpp b/b.cpp\n"

"--- a/b.cpp\n"

"+++ b/b.cpp\n"

"@@ -1,1 +1,1 @@\n"

"-p\n"

"+q\n";

auto r = GitDiffParser::parse(diff);

QCOMPARE(r.addedCount, 2);

QCOMPARE(r.deletedCount, 2);

int hunkHeaders = 0;

for (auto k : r.kinds) {

if (k == GitDiffParser::LineKind::HunkHeader) ++hunkHeaders;

}

QCOMPARE(hunkHeaders, 2);

}

void TestGitDiffParser::perf_5kLineDiff_under60ms()

{

// Build a synthetic 5k-line unified diff: alternating + / - / context lines

// across one large hunk, with realistic line widths.

QByteArray diff;

diff.reserve(5000 * 80);

diff.append("diff --git a/big.txt b/big.txt\n");

diff.append("--- a/big.txt\n");

diff.append("+++ b/big.txt\n");

diff.append("@@ -1,5000 +1,5000 @@\n");

const char *filler = "abcdefghij abcdefghij abcdefghij abcdefghij abcdefghij abcdefghij";

for (int i = 0; i < 5000; ++i) {

char prefix;

switch (i % 3) {

case 0: prefix = ' '; break;

case 1: prefix = '+'; break;

default: prefix = '-'; break;

}

diff.append(prefix);

diff.append(filler);

diff.append('\n');

}

// Warm up branch predictor / cache.

(void)GitDiffParser::parse(diff);

QElapsedTimer t;

qint64 best = std::numeric_limits<qint64>::max();

for (int run = 0; run < 3; ++run) {

t.start();

auto r = GitDiffParser::parse(diff);

const qint64 elapsed = t.nsecsElapsed();

best = std::min(best, elapsed);

// Sanity: the parsed result must contain all source lines.

QVERIFY(r.texts.size() >= 5000);

}

const double ms = best / 1.0e6;

qInfo() << "GitDiffParser 5k-line best:" << ms << "ms";

// Hard budget: parser must finish well under 60ms so the full

// parse+paint+focus chain stays under the user-perceived threshold.

QVERIFY2(ms < 60.0,

qPrintable(QString("Parser too slow: %1ms (>60ms)").arg(ms)));

}

QTEST_GUILESS_MAIN(TestGitDiffParser)

#include "test_git_diff_parser.moc"