QmlDesigner: Add string utils function

Add utilities for string matching and comment detection in QStringView

- Implemented `find_comment_end()` to locate the end of a comment block
or line.
- Move complex functions to .cpp file

Change-Id: Id544905d9486b6c4e7cddc91213956830937d8ae
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/libs/qmldesignerutils/CMakeLists.txt

@@ -17,7 +17,7 @@ add_qtc_library(QmlDesignerUtils STATIC
     qmldesignerutils_global.h
     version.cpp version.h
     maputils.h
-    stringutils.h
+    stringutils.cpp stringutils.h
 )
 
 extend_qtc_library(QmlDesignerUtils

src/plugins/qmldesigner/libs/qmldesignerutils/stringutils.cpp

@@ -0,0 +1,154 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "stringutils.h"
+
+namespace QmlDesigner::StringUtils {
+
+QString escape(QStringView text)
+{
+    using namespace Qt::StringLiterals;
+
+    if (text.size() == 6 && text.startsWith(u"\\u")) //Do not double escape unicode chars
+        return text.toString();
+
+    QString escapedText;
+    escapedText.reserve(text.size() * 2);
+
+    const auto end = text.end();
+    auto current = text.begin();
+    QStringView pattern = u"\\\"\t\r\n";
+    while (current != end) {
+        auto found = std::ranges::find_first_of(current, end, pattern.begin(), pattern.end());
+        escapedText.append(QStringView{current, found});
+
+        if (found == end)
+            break;
+
+        QChar c = *found;
+        switch (c.unicode()) {
+        case u'\\':
+            escapedText.append(u"\\\\");
+            break;
+        case u'\"':
+            escapedText.append(u"\\\"");
+            break;
+        case u'\t':
+            escapedText.append(u"\\t");
+            break;
+        case u'\r':
+            escapedText.append(u"\\r");
+            break;
+        case u'\n':
+            escapedText.append(u"\\n");
+            break;
+        }
+
+        current = std::next(found);
+    }
+
+    return escapedText;
+}
+
+QString deescape(QStringView text)
+{
+    using namespace Qt::StringLiterals;
+
+    if (text.isEmpty() || (text.size() == 6 && text.startsWith(u"\\u"))) //Ignore unicode chars
+        return text.toString();
+
+    QString deescapedText;
+    deescapedText.reserve(text.size());
+
+    const auto end = text.end();
+    auto current = text.begin();
+    while (current != end) {
+        auto found = std::ranges::find(current, end, u'\\');
+        deescapedText.append(QStringView{current, found});
+
+        if (found == end)
+            break;
+
+        current = std::next(found);
+
+        if (current == end) {
+            deescapedText.append(u'\\');
+            break;
+        }
+
+        QChar c = *current;
+        switch (c.unicode()) {
+        case u'\\':
+            deescapedText.append(u'\\');
+            current = std::next(current);
+            break;
+        case u'\"':
+            deescapedText.append(u'\"');
+            current = std::next(current);
+            break;
+        case u't':
+            deescapedText.append(u'\t');
+            current = std::next(current);
+            break;
+        case u'r':
+            deescapedText.append(u'\r');
+            current = std::next(current);
+            break;
+        case u'n':
+            deescapedText.append(u'\n');
+            current = std::next(current);
+            break;
+        default:
+            deescapedText.append(u'\\');
+            break;
+        }
+    }
+
+    return deescapedText;
+}
+
+namespace {
+enum class Comment { No, Line, Block };
+
+Comment commentKind(QStringView text)
+{
+    if (text.size() < 2)
+        return Comment::No;
+
+    if (text.startsWith(u"//"))
+        return Comment::Line;
+
+    if (text.startsWith(u"/*"))
+        return Comment::Block;
+
+    return Comment::No;
+}
+} // namespace
+
+QStringView::iterator find_comment_end(QStringView text)
+{
+    auto current = text.begin();
+    const auto end = text.end();
+
+    while (current != end) {
+        text = {current, text.end()};
+        switch (commentKind(text)) {
+        case Comment::No:
+            return current;
+        case Comment::Line:
+            current = std::ranges::find(text, u'\n');
+            break;
+        case Comment::Block:
+            current = std::ranges::search(text, QStringView{u"*/"}).end();
+            current = std::ranges::find(current, end, u'\n');
+            break;
+        }
+
+        if (current != end)
+            current = std::next(current);
+    }
+
+    return current;
+}
+
+} // namespace QmlDesigner::StringUtils

src/plugins/qmldesigner/libs/qmldesignerutils/stringutils.h

@@ -3,6 +3,8 @@
 
 #pragma once
 
+#include "qmldesignerutils_global.h"
+
 #include <QString>
 #include <QStringView>
 
@@ -11,107 +13,9 @@
 
 namespace QmlDesigner::StringUtils {
 
-inline QString escape(QStringView text)
+QMLDESIGNERUTILS_EXPORT QString escape(QStringView text);
-{
-    using namespace Qt::StringLiterals;
 
-    if (text.size() == 6 && text.startsWith(u"\\u")) //Do not double escape unicode chars
+QMLDESIGNERUTILS_EXPORT QString deescape(QStringView text);
-        return text.toString();
-
-    QString escapedText;
-    escapedText.reserve(text.size() * 2);
-
-    const auto end = text.end();
-    auto current = text.begin();
-    QStringView pattern = u"\\\"\t\r\n";
-    while (current != end) {
-        auto found = std::ranges::find_first_of(current, end, pattern.begin(), pattern.end());
-        escapedText.append(QStringView{current, found});
-
-        if (found == end)
-            break;
-
-        QChar c = *found;
-        switch (c.unicode()) {
-        case u'\\':
-            escapedText.append(u"\\\\");
-            break;
-        case u'\"':
-            escapedText.append(u"\\\"");
-            break;
-        case u'\t':
-            escapedText.append(u"\\t");
-            break;
-        case u'\r':
-            escapedText.append(u"\\r");
-            break;
-        case u'\n':
-            escapedText.append(u"\\n");
-            break;
-        }
-
-        current = std::next(found);
-    }
-
-    return escapedText;
-}
-
-inline QString deescape(QStringView text)
-{
-    using namespace Qt::StringLiterals;
-
-    if (text.isEmpty() || (text.size() == 6 && text.startsWith(u"\\u"))) //Ignore unicode chars
-        return text.toString();
-
-    QString deescapedText;
-    deescapedText.reserve(text.size());
-
-    const auto end = text.end();
-    auto current = text.begin();
-    while (current != end) {
-        auto found = std::ranges::find(current, end, u'\\');
-        deescapedText.append(QStringView{current, found});
-
-        if (found == end)
-            break;
-
-        current = std::next(found);
-
-        if (current == end) {
-            deescapedText.append(u'\\');
-            break;
-        }
-
-        QChar c = *current;
-        switch (c.unicode()) {
-        case u'\\':
-            deescapedText.append(u'\\');
-            current = std::next(current);
-            break;
-        case u'\"':
-            deescapedText.append(u'\"');
-            current = std::next(current);
-            break;
-        case u't':
-            deescapedText.append(u'\t');
-            current = std::next(current);
-            break;
-        case u'r':
-            deescapedText.append(u'\r');
-            current = std::next(current);
-            break;
-        case u'n':
-            deescapedText.append(u'\n');
-            current = std::next(current);
-            break;
-        default:
-            deescapedText.append(u'\\');
-            break;
-        }
-    }
-
-    return deescapedText;
-}
 
 template<typename T>
 concept is_object = std::is_object_v<T>;
@@ -128,4 +32,6 @@ inline std::pair<QStringView, QStringView> split_last(QStringView text, QChar c)
     return {{text.begin(), std::prev(splitPoint)}, {splitPoint, text.end()}};
 }
 
+QMLDESIGNERUTILS_EXPORT QStringView::iterator find_comment_end(QStringView text);
+
 } // namespace QmlDesigner::StringUtils

tests/unit/tests/unittests/qmldesignerutils/stringutils-test.cpp

@@ -8,6 +8,7 @@ namespace {
 
 using namespace Qt::StringLiterals;
 
+using QmlDesigner::StringUtils::find_comment_end;
 using QmlDesigner::StringUtils::split_last;
 
 TEST(StringUtils_split_last, leaf_is_empty_for_empty_input)
@@ -222,4 +223,63 @@ TEST_P(escaping, skip_unicode)
     ASSERT_THAT(converted, input);
 }
 
+TEST(StringUtils, find_comment_end_empty)
+{
+    QStringView input{};
+
+    auto found = find_comment_end(input);
+
+    ASSERT_THAT(found, input.end());
+}
+
+TEST(StringUtils, find_comment_end_line_comment)
+{
+    QStringView input{u"//foo\n//bar\nbar"};
+
+    auto found = find_comment_end(input);
+
+    QStringView text{found, input.end()};
+    ASSERT_THAT(text, u"bar");
+}
+
+TEST(StringUtils, find_comment_end_block_comment)
+{
+    QStringView input{u"/*foo\n//bar*/foo\nbar"};
+
+    auto found = find_comment_end(input);
+
+    QStringView text{found, input.end()};
+    ASSERT_THAT(text, u"bar");
+}
+
+TEST(StringUtils, find_comment_end_block_and_line_comment)
+{
+    QStringView input{u"//foo\n/*bar*/foo\nbar"};
+
+    auto found = find_comment_end(input);
+
+    QStringView text{found, input.end()};
+    ASSERT_THAT(text, u"bar");
+}
+
+TEST(StringUtils, find_comment_end_line_comment_has_no_newline)
+{
+    QStringView input{u"//foobar"};
+
+    auto found = find_comment_end(input);
+
+    QStringView text{found, input.end()};
+    ASSERT_THAT(text, input.end());
+}
+
+TEST(StringUtils, find_comment_end_block_comment_has_no_newline)
+{
+    QStringView input{u"//foo\n/*bar*/foo"};
+
+    auto found = find_comment_end(input);
+
+    QStringView text{found, input.end()};
+    ASSERT_THAT(text, input.end());
+}
+
 } // namespace