diff --git a/LLMClientInterface.cpp b/LLMClientInterface.cpp
index 5c9b421..370bb05 100644
--- a/LLMClientInterface.cpp
+++ b/LLMClientInterface.cpp
@@ -267,7 +267,7 @@ LLMCore::ContextData LLMClientInterface::prepareContext(
 
     Context::DocumentContextReader reader(
         textDocument->document(), textDocument->mimeType(), textDocument->filePath().toString());
-    return reader.prepareContext(lineNumber, cursorPosition);
+    return reader.prepareContext(lineNumber, cursorPosition, Settings::codeCompletionSettings());
 }
 
 void LLMClientInterface::sendCompletionToClient(
diff --git a/context/DocumentContextReader.cpp b/context/DocumentContextReader.cpp
index 7875c95..f76d9a1 100644
--- a/context/DocumentContextReader.cpp
+++ b/context/DocumentContextReader.cpp
@@ -244,39 +244,29 @@ CopyrightInfo DocumentContextReader::copyrightInfo() const
     return m_copyrightInfo;
 }
 
-LLMCore::ContextData DocumentContextReader::prepareContext(int lineNumber, int cursorPosition) const
+LLMCore::ContextData DocumentContextReader::prepareContext(
+    int lineNumber, int cursorPosition, const Settings::CodeCompletionSettings &settings) const
 {
-    QString contextBefore = getContextBefore(lineNumber, cursorPosition);
-    QString contextAfter = getContextAfter(lineNumber, cursorPosition);
+    QString contextBefore;
+    QString contextAfter;
+    if (settings.readFullFile()) {
+        contextBefore = readWholeFileBefore(lineNumber, cursorPosition);
+        contextAfter = readWholeFileAfter(lineNumber, cursorPosition);
+    } else {
+        contextBefore
+            = getContextBefore(lineNumber, cursorPosition, settings.readStringsBeforeCursor());
+        contextAfter
+            = getContextAfter(lineNumber, cursorPosition, settings.readStringsAfterCursor());
+    }
 
     QString fileContext;
     fileContext.append("\n ").append(getLanguageAndFileInfo());
 
-    if (Settings::codeCompletionSettings().useProjectChangesCache())
+    if (settings.useProjectChangesCache())
         fileContext.append("\n ").append(
             ChangesManager::instance().getRecentChangesContext(m_textDocument));
 
     return {.prefix = contextBefore, .suffix = contextAfter, .fileContext = fileContext};
 }
 
-QString DocumentContextReader::getContextBefore(int lineNumber, int cursorPosition) const
-{
-    if (Settings::codeCompletionSettings().readFullFile()) {
-        return readWholeFileBefore(lineNumber, cursorPosition);
-    } else {
-        int linesCount = Settings::codeCompletionSettings().readStringsBeforeCursor();
-        return getContextBefore(lineNumber, cursorPosition, linesCount);
-    }
-}
-
-QString DocumentContextReader::getContextAfter(int lineNumber, int cursorPosition) const
-{
-    if (Settings::codeCompletionSettings().readFullFile()) {
-        return readWholeFileAfter(lineNumber, cursorPosition);
-    } else {
-        int linesCount = Settings::codeCompletionSettings().readStringsAfterCursor();
-        return getContextAfter(lineNumber, cursorPosition, linesCount);
-    }
-}
-
 } // namespace QodeAssist::Context
diff --git a/context/DocumentContextReader.hpp b/context/DocumentContextReader.hpp
index 31aa91e..58cd1ec 100644
--- a/context/DocumentContextReader.hpp
+++ b/context/DocumentContextReader.hpp
@@ -23,6 +23,7 @@
 #include <QTextDocument>
 
 #include <llmcore/ContextData.hpp>
+#include <settings/CodeCompletionSettings.hpp>
 
 namespace QodeAssist::Context {
 
@@ -72,11 +73,8 @@ public:
 
     CopyrightInfo copyrightInfo() const;
 
-    LLMCore::ContextData prepareContext(int lineNumber, int cursorPosition) const;
-
-private:
-    QString getContextBefore(int lineNumber, int cursorPosition) const;
-    QString getContextAfter(int lineNumber, int cursorPosition) const;
+    LLMCore::ContextData prepareContext(
+        int lineNumber, int cursorPosition, const Settings::CodeCompletionSettings &settings) const;
 
 private:
     TextEditor::TextDocument *m_textDocument;
diff --git a/llmcore/ContextData.hpp b/llmcore/ContextData.hpp
index 1515540..1d862a5 100644
--- a/llmcore/ContextData.hpp
+++ b/llmcore/ContextData.hpp
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2024 Petr Mironychev
  *
  * This file is part of QodeAssist.
@@ -28,6 +28,10 @@ struct Message
 {
     QString role;
     QString content;
+
+    // clang-format off
+    auto operator<=>(const Message&) const = default;
+    // clang-format on
 };
 
 struct ContextData
@@ -37,6 +41,8 @@ struct ContextData
     std::optional<QString> suffix;
     std::optional<QString> fileContext;
     std::optional<QVector<Message>> history;
+
+    bool operator==(const ContextData &) const = default;
 };
 
 } // namespace QodeAssist::LLMCore
diff --git a/test/DocumentContextReaderTest.cpp b/test/DocumentContextReaderTest.cpp
index 8ace66f..fe0379e 100644
--- a/test/DocumentContextReaderTest.cpp
+++ b/test/DocumentContextReaderTest.cpp
@@ -20,16 +20,59 @@
 #include "context/DocumentContextReader.hpp"
 
 #include <gtest/gtest.h>
+#include <QSharedPointer>
 #include <QTextDocument>
 
 using namespace QodeAssist::Context;
+using namespace QodeAssist::LLMCore;
+using namespace QodeAssist::Settings;
 
 std::ostream &operator<<(std::ostream &out, const QString &value)
 {
-    out << value.toStdString();
+    out << '"' << value.toStdString() << '"';
     return out;
 }
 
+template<class T>
+std::ostream &operator<<(std::ostream &out, const QVector<T> &value)
+{
+    out << "[";
+    for (const auto &el : value) {
+        out << value << ", ";
+    }
+    out << "]";
+    return out;
+}
+
+template<class T>
+std::ostream &operator<<(std::ostream &out, const std::optional<T> &value)
+{
+    if (value.has_value()) {
+        out << value.value();
+    } else {
+        out << "(no value)";
+    }
+    return out;
+}
+
+namespace QodeAssist::LLMCore {
+std::ostream &operator<<(std::ostream &out, const Message &value)
+{
+    out << "Message{"
+        << "role=" << value.role << "content=" << value.content << "}";
+    return out;
+}
+
+std::ostream &operator<<(std::ostream &out, const ContextData &value)
+{
+    out << "ContextData{"
+        << "\n  systemPrompt=" << value.systemPrompt << "\n  prefix=" << value.prefix
+        << "\n  suffix=" << value.suffix << "\n  fileContext=" << value.fileContext
+        << "\n  history=" << value.history << "\n}";
+    return out;
+}
+} // namespace QodeAssist::LLMCore
+
 class DocumentContextReaderTest : public QObject, public testing::Test
 {
     Q_OBJECT
@@ -46,6 +89,24 @@ protected:
     {
         return DocumentContextReader(createTestDocument(text), "text/python", "/path/to/file");
     }
+
+    QSharedPointer<CodeCompletionSettings> createSettingsForWholeFile()
+    {
+        // CodeCompletionSettings is noncopyable
+        auto settings = QSharedPointer<CodeCompletionSettings>::create();
+        settings->readFullFile.setValue(true);
+        return settings;
+    }
+
+    QSharedPointer<CodeCompletionSettings> createSettingsForLines(int linesBefore, int linesAfter)
+    {
+        // CodeCompletionSettings is noncopyable
+        auto settings = QSharedPointer<CodeCompletionSettings>::create();
+        settings->readFullFile.setValue(false);
+        settings->readStringsBeforeCursor.setValue(linesBefore);
+        settings->readStringsAfterCursor.setValue(linesAfter);
+        return settings;
+    }
 };
 
 TEST_F(DocumentContextReaderTest, testGetLineText)
@@ -208,4 +269,30 @@ TEST_F(DocumentContextReaderTest, testGetContextBetween)
     EXPECT_EQ(reader.getContextBetween(1, 2, 3, 2), "ne 2\nLine 3\nLi");
 }
 
+TEST_F(DocumentContextReaderTest, testPrepareContext)
+{
+    auto reader = createTestReader("Line 1\nLine 2\nLine 3\nLine 4\nLine 5");
+
+    EXPECT_EQ(
+        reader.prepareContext(2, 3, *createSettingsForWholeFile()),
+        (ContextData{
+            .prefix = "Line 1\nLine 2\nLin",
+            .suffix = "e 3\nLine 4\nLine 5",
+            .fileContext = "\n Language:  (MIME: text/python) filepath: /path/to/file()\n\n\n "}));
+
+    EXPECT_EQ(
+        reader.prepareContext(2, 3, *createSettingsForLines(1, 1)),
+        (ContextData{
+            .prefix = "Lin",
+            .suffix = "e 3",
+            .fileContext = "\n Language:  (MIME: text/python) filepath: /path/to/file()\n\n\n "}));
+
+    EXPECT_EQ(
+        reader.prepareContext(2, 3, *createSettingsForLines(2, 2)),
+        (ContextData{
+            .prefix = "Line 2\nLin",
+            .suffix = "e 3\nLine 4",
+            .fileContext = "\n Language:  (MIME: text/python) filepath: /path/to/file()\n\n\n "}));
+}
+
 #include "DocumentContextReaderTest.moc"