From bc2713ccbbb857ece8329b1b0eb0ef68e17e4d50 Mon Sep 17 00:00:00 2001
From: Adriaan de Groot <groot@kde.org>
Date: Wed, 8 Dec 2021 14:08:37 +0100
Subject: [PATCH] [libcalamares] Add string functions for lstrip() and
 rstrip()-like

---
 src/libcalamares/utils/String.cpp | 21 ++++++++++
 src/libcalamares/utils/String.h   | 13 ++++++
 src/libcalamares/utils/Tests.cpp  | 68 +++++++++++++++++++++++++++++--
 3 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/src/libcalamares/utils/String.cpp b/src/libcalamares/utils/String.cpp
index 615d30309..c88c23693 100644
--- a/src/libcalamares/utils/String.cpp
+++ b/src/libcalamares/utils/String.cpp
@@ -224,5 +224,26 @@ truncateMultiLine( const QString& string, CalamaresUtils::LinesStartEnd lines, C
     return front + back.right( chars.total / 2 );
 }
 
+void
+removeLeading( QString& string, QChar c )
+{
+    int count = 0;
+    while ( string.length() > count && string[ count ] == c )
+    {
+        count++;
+    }
+    string.remove( 0, count );
+}
+
+void
+removeTrailing( QString& string, QChar c )
+{
+    int lastIndex = string.length();
+    while ( lastIndex > 0 && string[ lastIndex - 1 ] == c )
+    {
+        lastIndex--;
+    }
+    string.remove( lastIndex, string.length() );
+}
 
 }  // namespace CalamaresUtils
diff --git a/src/libcalamares/utils/String.h b/src/libcalamares/utils/String.h
index e08255f86..1adc2336a 100644
--- a/src/libcalamares/utils/String.h
+++ b/src/libcalamares/utils/String.h
@@ -100,6 +100,19 @@ DLLEXPORT QString truncateMultiLine( const QString& string,
                                      LinesStartEnd lines = LinesStartEnd { 3, 5 },
                                      CharCount chars = CharCount { 812 } );
 
+/** @brief Remove all @p c at the beginning of @p string
+ *
+ * Modifies the @p string in-place. If @p c is not the first character
+ * of @p string, the string is left unchanged; otherwise the first character
+ * is removed and the process repeats.
+ */
+DLLEXPORT void removeLeading( QString& string, QChar c );
+/** @brief Remove all @p c at the end of @p string
+ *
+ * Like removeLeading(), but at the end of the string.
+ */
+DLLEXPORT void removeTrailing( QString& string, QChar c );
+
 }  // namespace CalamaresUtils
 
 #endif
diff --git a/src/libcalamares/utils/Tests.cpp b/src/libcalamares/utils/Tests.cpp
index 8fd11cd87..3dde75338 100644
--- a/src/libcalamares/utils/Tests.cpp
+++ b/src/libcalamares/utils/Tests.cpp
@@ -70,6 +70,10 @@ private Q_SLOTS:
     void testStringTruncation();
     void testStringTruncationShorter();
     void testStringTruncationDegenerate();
+    void testStringRemoveLeading_data();
+    void testStringRemoveLeading();
+    void testStringRemoveTrailing_data();
+    void testStringRemoveTrailing();
 
     /** @section Test Runner directory-manipulation. */
     void testRunnerDirs();
@@ -754,6 +758,64 @@ LibCalamaresTests::testStringTruncationDegenerate()
     }
 }
 
+void
+LibCalamaresTests::testStringRemoveLeading_data()
+{
+    QTest::addColumn< QString >( "string" );
+    QTest::addColumn< char >( "c" );
+    QTest::addColumn< QString >( "result" );
+
+    QTest::newRow( "empty" ) << QString() << '/' << QString();
+    QTest::newRow( "one-slash" ) << QStringLiteral( "/tmp" ) << '/' << QStringLiteral( "tmp" );
+    QTest::newRow( "two-slash" ) << QStringLiteral( "//tmp" ) << '/' << QStringLiteral( "tmp" );
+    QTest::newRow( "multi-slash" ) << QStringLiteral( "/tmp/p" ) << '/' << QStringLiteral( "tmp/p" );
+    QTest::newRow( "later-slash" ) << QStringLiteral( "@/tmp" ) << '/' << QStringLiteral( "@/tmp" );
+    QTest::newRow( "all-one-slash" ) << QStringLiteral( "/" ) << '/' << QString();
+    QTest::newRow( "all-many-slash" ) << QStringLiteral( "////////////////////" ) << '/' << QString();
+    QTest::newRow( "trailing" ) << QStringLiteral( "tmp/" ) << '/' << QStringLiteral( "tmp/" );
+}
+
+void
+LibCalamaresTests::testStringRemoveLeading()
+{
+    QFETCH( QString, string );
+    QFETCH( char, c );
+    QFETCH( QString, result );
+
+    const QString initial = string;
+    CalamaresUtils::removeLeading( string, c );
+    QCOMPARE( string, result );
+}
+
+void
+LibCalamaresTests::testStringRemoveTrailing_data()
+{
+    QTest::addColumn< QString >( "string" );
+    QTest::addColumn< char >( "c" );
+    QTest::addColumn< QString >( "result" );
+
+    QTest::newRow( "empty" ) << QString() << '/' << QString();
+    QTest::newRow( "one-slash" ) << QStringLiteral( "/tmp" ) << '/' << QStringLiteral( "/tmp" );
+    QTest::newRow( "two-slash" ) << QStringLiteral( "//tmp" ) << '/' << QStringLiteral( "//tmp" );
+    QTest::newRow( "multi-slash" ) << QStringLiteral( "/tmp//p/" ) << '/' << QStringLiteral( "/tmp//p" );
+    QTest::newRow( "later-slash" ) << QStringLiteral( "@/tmp/@" ) << '/' << QStringLiteral( "@/tmp/@" );
+    QTest::newRow( "later-slash2" ) << QStringLiteral( "@/tmp/@//" ) << '/' << QStringLiteral( "@/tmp/@" );
+    QTest::newRow( "all-one-slash" ) << QStringLiteral( "/" ) << '/' << QString();
+    QTest::newRow( "all-many-slash" ) << QStringLiteral( "////////////////////" ) << '/' << QString();
+    QTest::newRow( "trailing" ) << QStringLiteral( "tmp/" ) << '/' << QStringLiteral( "tmp" );
+}
+
+void
+LibCalamaresTests::testStringRemoveTrailing()
+{
+    QFETCH( QString, string );
+    QFETCH( char, c );
+    QFETCH( QString, result );
+
+    const QString initial = string;
+    CalamaresUtils::removeTrailing( string, c );
+    QCOMPARE( string, result );
+}
 
 static QString
 dirname( const QTemporaryDir& d )
@@ -1001,10 +1063,10 @@ LibCalamaresTests::testReadWriteFile()
     {
         auto fullPath = ss->createTargetFile( "test0", otherContents );
         QVERIFY( !fullPath );  // Failed, because it won't overwrite
-        QCOMPARE( fullPath.code(), decltype(fullPath)::Code::AlreadyExists );
-        QVERIFY( fullPath.path().isEmpty() ); // Because it wasn't written
+        QCOMPARE( fullPath.code(), decltype( fullPath )::Code::AlreadyExists );
+        QVERIFY( fullPath.path().isEmpty() );  // Because it wasn't written
 
-        QFileInfo fi( tempRoot.filePath( "test0" ) ); // Compute the name some other way
+        QFileInfo fi( tempRoot.filePath( "test0" ) );  // Compute the name some other way
         QVERIFY( fi.exists() );
         QVERIFY( fi.isFile() );
         QCOMPARE( fi.size(), 0 );