diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6847108..b812c42 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: danger89/gtk3-docker-cmake-ninja:2.5
+image: danger89/gtk3-docker-cmake-ninja:3.0
 stages:
   - build
   #- upload
@@ -41,10 +41,9 @@ code_style_guidelines:
   stage: build
   script: "./scripts/check-format.sh"
 
-# TODO: Testing!
-#unit_test:
-#  stage: test
-#  script :
+unit_test:
+  stage: test
+  script: "./scripts/build-run-tests.sh"
 
 sast:
   stage: test
diff --git a/.vscode/cmake-variants.json b/.vscode/cmake-variants.json
new file mode 100644
index 0000000..a08f520
--- /dev/null
+++ b/.vscode/cmake-variants.json
@@ -0,0 +1,40 @@
+{
+  "buildType": {
+    "default": "debug",
+    "choices": {
+      "debug": {
+        "short": "Debug",
+        "long": "Emit debug information without performing optimizations",
+        "buildType": "Debug",
+        "settings": {
+          "UNITTEST": false
+        }
+      },
+      "release": {
+        "short": "Release",
+        "long": "Enable optimizations, omit debug info",
+        "buildType": "Release",
+        "settings": {
+          "UNITTEST": false
+        }
+      },
+      "reldeb": {
+        "short": "RelWithDebInfo",
+        "long": "Perform optimizations AND include debugging information",
+        "buildType": "RelWithDebInfo",
+        "settings": {
+          "UNITTEST": false
+        }
+      },
+      "test": {
+        "short": "UnitTests",
+        "long": "Build + run unit tests",
+        "buildType": "Debug",
+        "settings": {
+          "UNITTEST": true,
+          "DOXYGEN": false
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 521c887..a8e1df2 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -80,6 +80,7 @@
         "node.h": "c",
         "*.in": "cpp",
         "superscript.h": "c",
-        "cmark-gfm.h": "c"
+        "cmark-gfm.h": "c",
+        "any": "cpp"
     }
 }
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index aabe9af..48bb364 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,7 @@
 cmake_minimum_required (VERSION 3.16.0)
 
 option(DOXYGEN "Build Doxygen documentation" ON)
+option(UNITTEST "Build unit tests")
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 
@@ -13,6 +14,9 @@ project(libreweb-browser
 
 message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
 message(STATUS "PROJECT_VERSION: ${PROJECT_VERSION}")
+if(UNITTEST)
+  message(STATUS "Building the unit tests")
+endif()
 
 # Build docs using Doxygen
 if(DOXYGEN)
@@ -38,7 +42,7 @@ if(WIN32)
   set(WINDOWS_FLAGS -mwindows)
 endif()
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -pedantic -Werror=incompatible-pointer-types")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}  -Wall")
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O3 -DNDEBUG")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror")
@@ -55,6 +59,10 @@ add_subdirectory (lib/ipfs-http-client)
 add_subdirectory (lib/whereami)
 add_subdirectory (src)
 
+if(UNITTEST)
+  add_subdirectory(tst)
+endif()
+
 # Additional install files
 if(WIN32)
   # Windows specific
diff --git a/README.md b/README.md
index e7bc848..3259029 100644
--- a/README.md
+++ b/README.md
@@ -79,9 +79,13 @@ For the GNU/Linux build you need at least:
 * Libcurl (Package: `libcurl4-openssl-dev`)
 * GTK & Pango (including C++ bindings):
   * Package: `libgtkmm-3.0-dev` under Debian based distros
+
+Depedencies for tests:
+
+* X virtual framebuffer (Package: `xvfb`)
 * Clang-format (Package: `clang-format`)
 
-*Note:* For cross-compiling towards Windows, see the cross-compile section below.
+*Note:* For cross-compiling towards Windows, see the cross-compile section down below.
 
 ### Build
 
@@ -99,9 +103,23 @@ Start the Linux build, which is using CMake and Ninja build system, using the wr
 
 Optionally, use the VSCode `CMake Tools` extension to start the build or build with debug targets.
 
-Build a release target, including packaging under GNU/Linux, using: `./scripts/build-lnx-prod.sh`
+#### Linux Packaging
 
-*Note:* Root access is required for Linux packaging; add `/opt/mxe/usr/bin` to the secure_path using: `sudo visudo`.
+*Note:* (Linux) Packages are already [available under releases](https://gitlab.melroy.org/libreweb/browser/-/releases).
+
+To build a release target yourself including packaging under GNU/Linux, use: `./scripts/build-lnx-prod.sh`
+
+Root access is required when building Linux packages; add `/opt/mxe/usr/bin` to the secure_path using: `sudo visudo`.
+
+### Unit testing
+
+To execute the **unit tests** you can configure with `cmake -DUNITTEST:BOOL=TRUE` and build. Execute: `ctest` command in the `tst` target directory.
+
+Or just use script:
+
+```sh
+./scripts/build-run-tests.sh
+```
 
 ### C++ Coding Style Guidelines
 
diff --git a/scripts/build-docs.sh b/scripts/build-docs.sh
index 20bb8ca..4d4343f 100755
--- a/scripts/build-docs.sh
+++ b/scripts/build-docs.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # By: Melroy van den Berg
-# Descriptiopn: Only build the documentation (used in CI/CD)
+# Description: Only build the documentation (used in CI/CD)
 
 mkdir build_docs
 cd build_docs
diff --git a/scripts/build-lnx-no-docs.sh b/scripts/build-lnx-no-docs.sh
new file mode 100755
index 0000000..2eaa509
--- /dev/null
+++ b/scripts/build-lnx-no-docs.sh
@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# By: Melroy van den Berg
+# Description: Development build for Linux, same as build-lnx.sh but without Doxygen
+
+if [ ! -d "build" ]; then
+  echo "Creating build directory..."
+  mkdir build
+fi
+
+if [ -z "$(ls build)" ]; then
+  echo "INFO: Run cmake & ninja"
+  cd build
+  cmake -G Ninja -DDOXYGEN:BOOL=FALSE ..
+else
+  echo "INFO: Only run ninja..."
+  cd build
+fi
+ninja
diff --git a/scripts/build-run-tests.sh b/scripts/build-run-tests.sh
new file mode 100755
index 0000000..5a6a538
--- /dev/null
+++ b/scripts/build-run-tests.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# By: Melroy van den Berg
+# Description: Build & run unit-tests
+
+if [ ! -d "build_test" ]; then
+  echo "Creating test build directory..."
+  mkdir build_test
+fi
+
+if [ -z "$(ls build_test)" ]; then
+  echo "INFO: Run cmake & ninja"
+  cd build_test
+  cmake -G Ninja -DDOXYGEN:BOOL=FALSE -DUNITTEST:BOOL=TRUE ..
+else
+  echo "INFO: Only run ninja..."
+  cd build_test
+fi
+# Build & run unit tests
+ninja tests
diff --git a/scripts/check-format.sh b/scripts/check-format.sh
index 7e6bafc..d7e5c47 100755
--- a/scripts/check-format.sh
+++ b/scripts/check-format.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 # Description: Check the coding style guidelines (only dry-run)
-find src/ -iname *.h -o -iname *.cc -o -iname *.h.in | xargs clang-format --dry-run -Werror -style=file -fallback-style=LLVM
+find src/ tst/ -iname *.h -o -iname *.cc -o -iname *.h.in | xargs clang-format --dry-run -Werror -style=file -fallback-style=LLVM
diff --git a/scripts/cpp-check.sh b/scripts/cpp-check.sh
index fc3494c..732cab7 100755
--- a/scripts/cpp-check.sh
+++ b/scripts/cpp-check.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 # TODO: add to following flag to the cppcheck: --addon=cert
-cppcheck --enable=all --suppressions-list=suppressions.txt --error-exitcode=1 "$@" -I lib/commonmarker/src/ -I lib/commonmarker/extensions/ ./src
+cppcheck --enable=all --library=googletest --suppressions-list=suppressions.txt --error-exitcode=1 "$@" -I lib/commonmarker/src/ -I lib/commonmarker/extensions/ ./src ./tst
diff --git a/scripts/fix-format.sh b/scripts/fix-format.sh
index b82df8c..ea39213 100755
--- a/scripts/fix-format.sh
+++ b/scripts/fix-format.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 # Description: Check the coding style guidelines & fix them automatically
-find src/ -iname *.h -o -iname *.cc -o -iname *.h.in | xargs clang-format -i -style=file -fallback-style=LLVM -assume-filename=../.clang-format
+find src/ tst/ -iname *.h -o -iname *.cc -o -iname *.h.in | xargs clang-format -i -style=file -fallback-style=LLVM -assume-filename=../.clang-format
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 21cb67f..87e81c5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,6 +1,7 @@
 include(${CMAKE_SOURCE_DIR}/cmake/GSettings.cmake)
 
 set(PROJECT_TARGET libreweb-browser)
+set(PROJECT_TARGET_LIB ${PROJECT_TARGET}-lib)
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 
 # Find required dependencies
@@ -11,7 +12,7 @@ pkg_check_modules(GTKMM REQUIRED gtkmm-3.0)
 # Generate Project version header file
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/project_config.h.in ${CMAKE_CURRENT_BINARY_DIR}/project_config.h)
 
-# In order to find project_config.h
+# Include the binary dir, in order to find project_config.h
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 # Source code
@@ -20,6 +21,7 @@ set(HEADERS
     draw.h
     file.h
     ipfs.h
+    middleware-i.h
     middleware.h
     toolbar-button.h
     mainwindow.h
@@ -76,52 +78,83 @@ if(WIN32)
 	set_source_files_properties(${WINDOWS_RES} PROPERTIES LANGUAGE RC)
 endif()
 
-add_executable(${PROJECT_TARGET} ${GSCHEMA_RING} ${WINDOWS_RES} ${SOURCES})
-
-## Definitions just in case
-# Define _WIN32 for Windows platforms
-if(WIN32)
-    target_compile_definitions(${PROJECT_TARGET} PRIVATE _WIN32)
-endif()
-# Define __linux__ for Unix platforms
-if (UNIX)
-    target_compile_definitions(${PROJECT_TARGET} PRIVATE __linux__)
-endif()
-
-# Add fallback for std filesystem in older GCC versions
-if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-    if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.4)
-        message(FATAL_ERROR "You are on an extremely old version of GCC. Please update your compiler to at least GCC 8.0, preferably latest")
-    elseif (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
-        message(WARNING "Old Version of GCC detected. Using Legacy C++ support")
-        # Add stdc++fs library in older GCC compiler versions
-        set(CXX_FILESYSTEM_LIBRARIES "stdc++fs")
-        target_compile_definitions(${PROJECT_TARGET} PUBLIC LEGACY_CXX)
-    endif()
-endif()
-
 # Get include list the cmark binary directory for the generated config.h, .._version.h & .._export.h files
 # Get include list the cmark extensions binary directory for the generated ..._export.h file
-get_property(CMAKE_BINARY_DIR GLOBAL PROPERTY COMMONMARKER_BINARY_DIR)
-get_property(CMAKE_EXTENSIONS_BINARY_DIR GLOBAL PROPERTY COMMONMARKER_EXTENSIONS_BINARY_DIR)
+get_property(CMARK_BINARY_DIR GLOBAL PROPERTY COMMONMARKER_BINARY_DIR)
+get_property(CMARK_EXTENSIONS_BINARY_DIR GLOBAL PROPERTY COMMONMARKER_EXTENSIONS_BINARY_DIR)
 
-target_include_directories(${PROJECT_TARGET} PRIVATE
-    ${CMAKE_BINARY_DIR}
-    ${CMAKE_EXTENSIONS_BINARY_DIR}
-    ${GTKMM_INCLUDE_DIRS}
-)
-target_link_directories(${PROJECT_TARGET} PRIVATE ${GTKMM_LIBRARY_DIRS})
-target_link_libraries(${PROJECT_TARGET} PRIVATE
-    LibCommonMarker
-    LibCommonMarkerExtensions
-    ipfs-http-client
-    whereami
-    Threads::Threads
-    ${CXX_FILESYSTEM_LIBRARIES}
-    ${GTKMM_LIBRARIES}
-    nlohmann_json::nlohmann_json
-)
-target_compile_options(${PROJECT_TARGET} PRIVATE ${GTKMM_CFLAGS_OTHER})
+if(NOT UNITTEST)
+    # LibreWeb binary
+    add_executable(${PROJECT_TARGET} ${GSCHEMA_RING} ${WINDOWS_RES} ${SOURCES})
 
-# Install browser binary
-install(TARGETS ${PROJECT_TARGET} RUNTIME DESTINATION bin)
+    ## Definitions just in case
+    # Define _WIN32 for Windows platforms
+    if(WIN32)
+        target_compile_definitions(${PROJECT_TARGET} PRIVATE _WIN32)
+    endif()
+    # Define __linux__ for Unix platforms
+    if (UNIX)
+        target_compile_definitions(${PROJECT_TARGET} PRIVATE __linux__)
+    endif()
+
+    # Add fallback for std filesystem in older GCC versions
+    if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+        if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.4)
+            message(FATAL_ERROR "You are on an extremely old version of GCC. Please update your compiler to at least GCC 8.0, preferably latest")
+        elseif (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
+            message(WARNING "Old Version of GCC detected. Using Legacy C++ support")
+            # Add stdc++fs library in older GCC compiler versions
+            set(CXX_FILESYSTEM_LIBRARIES "stdc++fs")
+            target_compile_definitions(${PROJECT_TARGET} PUBLIC LEGACY_CXX)
+        endif()
+    endif()
+
+    target_include_directories(${PROJECT_TARGET} PRIVATE
+        ${CMARK_BINARY_DIR}
+        ${CMARK_EXTENSIONS_BINARY_DIR}
+        ${GTKMM_INCLUDE_DIRS}
+    )
+    target_link_directories(${PROJECT_TARGET} PRIVATE ${GTKMM_LIBRARY_DIRS})
+    target_link_libraries(${PROJECT_TARGET} PRIVATE
+        LibCommonMarker
+        LibCommonMarkerExtensions
+        ipfs-http-client
+        whereami
+        Threads::Threads
+        ${CXX_FILESYSTEM_LIBRARIES}
+        ${GTKMM_LIBRARIES}
+        nlohmann_json::nlohmann_json
+    )
+    target_compile_options(${PROJECT_TARGET} PRIVATE ${GTKMM_CFLAGS_OTHER})
+
+    # Install browser binary
+    install(TARGETS ${PROJECT_TARGET} RUNTIME DESTINATION bin)
+else()
+    # Build libraries for unit testing
+    add_library(${PROJECT_TARGET_LIB}-file STATIC file.h file.cc)
+    add_library(${PROJECT_TARGET_LIB}-draw STATIC draw.h draw.cc md-parser.h md-parser.cc)
+    add_library(${PROJECT_TARGET_LIB}-parser STATIC md-parser.h md-parser.cc)
+
+    # Only link/include external libs we really need for the unittest libaries
+    target_include_directories(${PROJECT_TARGET_LIB}-draw PRIVATE
+        ${CMARK_BINARY_DIR}
+        ${CMARK_EXTENSIONS_BINARY_DIR}
+        ${GTKMM_INCLUDE_DIRS}
+    )
+    target_link_libraries(${PROJECT_TARGET_LIB}-draw PRIVATE
+        LibCommonMarker
+        LibCommonMarkerExtensions
+        ${GTKMM_LIBRARIES}
+    )
+    target_compile_options(${PROJECT_TARGET_LIB}-draw PRIVATE ${GTKMM_CFLAGS_OTHER})
+    target_include_directories(${PROJECT_TARGET_LIB}-parser PRIVATE
+        ${CMARK_BINARY_DIR}
+        ${CMARK_EXTENSIONS_BINARY_DIR}
+        ${GTKMM_INCLUDE_DIRS}
+    )
+    target_link_directories(${PROJECT_TARGET_LIB}-parser PRIVATE ${GTKMM_LIBRARY_DIRS})
+    target_link_libraries(${PROJECT_TARGET_LIB}-parser PRIVATE
+        LibCommonMarker
+        LibCommonMarkerExtensions
+    )
+endif()
\ No newline at end of file
diff --git a/src/draw.cc b/src/draw.cc
index 1854db0..990c65f 100644
--- a/src/draw.cc
+++ b/src/draw.cc
@@ -1,7 +1,6 @@
 #include "draw.h"
-#include "middleware.h"
+#include "middleware-i.h"
 #include "node.h"
-#include "strikethrough.h"
 #include "syntax_extension.h"
 #include <cmark-gfm.h>
 #include <gdkmm/window.h>
@@ -11,7 +10,7 @@
 #include <regex>
 #include <stdexcept>
 
-Draw::Draw(Middleware& middleware)
+Draw::Draw(MiddlewareInterface& middleware)
     : middleware(middleware),
       buffer(Glib::unwrap(this->get_buffer())),
       addViewSourceMenuItem(true),
@@ -351,7 +350,7 @@ void Draw::newDocument()
  */
 Glib::ustring Draw::getText() const
 {
-  return get_buffer().get()->get_text();
+  return get_buffer()->get_text();
 }
 
 /**
diff --git a/src/draw.h b/src/draw.h
index 70c8514..b333309 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -8,7 +8,7 @@
 #include <gtkmm/tooltip.h>
 #include <pangomm/layout.h>
 
-class Middleware;
+class MiddlewareInterface;
 
 /**
  * \struct UndoRedoData
@@ -37,7 +37,7 @@ public:
     CODE_TYPE_CODE_BLOCK
   };
 
-  explicit Draw(Middleware& middleware);
+  explicit Draw(MiddlewareInterface& middleware);
   void setMessage(const Glib::ustring& message, const Glib::ustring& details = "");
   void showStartPage();
   void setDocument(cmark_node* rootNode);
@@ -81,7 +81,7 @@ protected:
   void populate_popup(Gtk::Menu* menu);
 
 private:
-  Middleware& middleware;
+  MiddlewareInterface& middleware;
   GtkTextBuffer* buffer;
   bool addViewSourceMenuItem;
   int headingLevel;
diff --git a/src/file.cc b/src/file.cc
index 48032ec..9a8a139 100644
--- a/src/file.cc
+++ b/src/file.cc
@@ -1,6 +1,5 @@
 #include "file.h"
 #include <fstream>
-#include <ipfs/client.h>
 #include <stdexcept>
 
 #ifdef LEGACY_CXX
diff --git a/src/ipfs.cc b/src/ipfs.cc
index ddba7a2..217076e 100644
--- a/src/ipfs.cc
+++ b/src/ipfs.cc
@@ -15,7 +15,7 @@ IPFS::IPFS(const std::string& host, int port, const std::string& timeout)
 }
 
 /**
- * \brief Get the number of IPFS peers. Does not throw errors.
+ * \brief Get the number of IPFS peers.
  * \return number of peers as size_t
  */
 std::size_t IPFS::getNrPeers()
@@ -26,7 +26,7 @@ std::size_t IPFS::getNrPeers()
 }
 
 /**
- * \brief Retrieve your IPFS client ID. Does not throw errors.
+ * \brief Retrieve your IPFS client ID.
  * \return ID as string
  */
 std::string IPFS::getClientID()
@@ -37,7 +37,7 @@ std::string IPFS::getClientID()
 }
 
 /**
- * \brief Retrieve your IPFS Public Key. Does not throw errors.
+ * \brief Retrieve your IPFS Public Key.
  * \return Public key string
  */
 std::string IPFS::getClientPublicKey()
@@ -48,7 +48,7 @@ std::string IPFS::getClientPublicKey()
 }
 
 /**
- * \brief Retrieve the Go IPFS daemon version. Does not throw errors.
+ * \brief Retrieve the Go IPFS daemon version.
  * \return Version string
  */
 std::string IPFS::getVersion()
@@ -59,7 +59,7 @@ std::string IPFS::getVersion()
 }
 
 /**
- * \brief Get the number of IPFS peers. Does not throw errors.
+ * \brief Get the number of IPFS peers.
  * \return Map with bandwidth information (with keys: 'in' and 'out')
  */
 std::map<std::string, float> IPFS::getBandwidthRates()
@@ -75,7 +75,7 @@ std::map<std::string, float> IPFS::getBandwidthRates()
 }
 
 /**
- * \brief Get the stats of the current Repo. Does not throw errors.
+ * \brief Get the stats of the current Repo.
  * \return Map with repo stats (with keys: 'repo-size' and 'path')
  */
 std::map<std::string, std::variant<int, std::string>> IPFS::getRepoStats()
diff --git a/src/middleware-i.h b/src/middleware-i.h
new file mode 100644
index 0000000..06f07f7
--- /dev/null
+++ b/src/middleware-i.h
@@ -0,0 +1,41 @@
+#ifndef MIDDLEWARE_INTERFACE_H
+#define MIDDLEWARE_INTERFACE_H
+
+#include <glibmm/ustring.h>
+#include <string>
+
+/* Forward declarations */
+struct cmark_node;
+
+/**
+ * \class MiddlewareInterface
+ * \brief Pure Middleware interface
+ */
+class MiddlewareInterface
+{
+public:
+  virtual ~MiddlewareInterface()
+  {
+  }
+  virtual void doRequest(const std::string& path = std::string(),
+                         bool isSetAddressBar = true,
+                         bool isHistoryRequest = false,
+                         bool isDisableEditor = true,
+                         bool isParseContent = true) = 0;
+  virtual std::string doAdd(const std::string& path) = 0;
+  virtual void doWrite(const std::string& path, bool isSetAddressAndTitle = true) = 0;
+  virtual void setContent(const Glib::ustring& content) = 0;
+  virtual Glib::ustring getContent() const = 0;
+  virtual cmark_node* parseContent() const = 0;
+  virtual void resetContentAndPath() = 0;
+  virtual std::size_t getIPFSNumberOfPeers() const = 0;
+  virtual int getIPFSRepoSize() const = 0;
+  virtual std::string getIPFSRepoPath() const = 0;
+  virtual std::string getIPFSIncomingRate() const = 0;
+  virtual std::string getIPFSOutcomingRate() const = 0;
+  virtual std::string getIPFSVersion() const = 0;
+  virtual std::string getIPFSClientId() const = 0;
+  virtual std::string getIPFSClientPublicKey() const = 0;
+};
+
+#endif
\ No newline at end of file
diff --git a/src/middleware.cc b/src/middleware.cc
index 6f34cf4..5d833da 100644
--- a/src/middleware.cc
+++ b/src/middleware.cc
@@ -130,7 +130,8 @@ Glib::ustring Middleware::getContent() const
 }
 
 /**
- * \brief Current content parser middleware
+ * \brief Current content parser middleware.
+ * Note: Do not forget to free the document: cmark_node_free(root_node;
  * \return AST structure (of type cmark_node)
  */
 cmark_node* Middleware::parseContent() const
diff --git a/src/middleware.h b/src/middleware.h
index 0267d03..bd58f78 100644
--- a/src/middleware.h
+++ b/src/middleware.h
@@ -2,15 +2,14 @@
 #define MIDDLEWARE_H
 
 #include "ipfs.h"
+#include "middleware-i.h"
 #include <atomic>
 #include <glibmm/dispatcher.h>
 #include <glibmm/ustring.h>
-#include <map>
 #include <mutex>
 #include <sigc++/connection.h>
 #include <string>
 #include <thread>
-#include <variant>
 
 /* Forward declarations */
 struct cmark_node;
@@ -20,7 +19,7 @@ class MainWindow;
  * \class Middleware
  * \brief Handles (IPFS) network requests and File IO from disk towards the GUI
  */
-class Middleware
+class Middleware : public MiddlewareInterface
 {
 public:
   explicit Middleware(MainWindow& mainWindow, const std::string& timeout);
@@ -29,21 +28,21 @@ public:
                  bool isSetAddressBar = true,
                  bool isHistoryRequest = false,
                  bool isDisableEditor = true,
-                 bool isParseContent = true);
-  std::string doAdd(const std::string& path);
-  void doWrite(const std::string& path, bool isSetAddressAndTitle = true);
-  void setContent(const Glib::ustring& content);
-  Glib::ustring getContent() const;
-  cmark_node* parseContent() const;
-  void resetContentAndPath();
-  std::size_t getIPFSNumberOfPeers() const;
-  int getIPFSRepoSize() const;
-  std::string getIPFSRepoPath() const;
-  std::string getIPFSIncomingRate() const;
-  std::string getIPFSOutcomingRate() const;
-  std::string getIPFSVersion() const;
-  std::string getIPFSClientId() const;
-  std::string getIPFSClientPublicKey() const;
+                 bool isParseContent = true) override;
+  std::string doAdd(const std::string& path) override;
+  void doWrite(const std::string& path, bool isSetAddressAndTitle = true) override;
+  void setContent(const Glib::ustring& content) override;
+  Glib::ustring getContent() const override;
+  cmark_node* parseContent() const override;
+  void resetContentAndPath() override;
+  std::size_t getIPFSNumberOfPeers() const override;
+  int getIPFSRepoSize() const override;
+  std::string getIPFSRepoPath() const override;
+  std::string getIPFSIncomingRate() const override;
+  std::string getIPFSOutcomingRate() const override;
+  std::string getIPFSVersion() const override;
+  std::string getIPFSClientId() const override;
+  std::string getIPFSClientPublicKey() const override;
 
 private:
   MainWindow& mainWindow;
diff --git a/tst/CMakeLists.txt b/tst/CMakeLists.txt
new file mode 100644
index 0000000..cd56fc1
--- /dev/null
+++ b/tst/CMakeLists.txt
@@ -0,0 +1,41 @@
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTKMM REQUIRED gtkmm-3.0)
+
+include(FetchContent)
+FetchContent_Declare(
+  googletest
+  URL https://github.com/google/googletest/archive/e2239ee6043f73722e7aa812a459f54a28552929.zip
+)
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(googletest)
+
+get_property(CMARK_BINARY_DIR GLOBAL PROPERTY COMMONMARKER_BINARY_DIR)
+
+enable_testing()
+
+add_executable(draw draw_test.cc mock-middleware.h)
+target_include_directories(draw PRIVATE ${CMAKE_SOURCE_DIR}/src ${CMARK_BINARY_DIR} ${GTKMM_INCLUDE_DIRS})
+target_link_libraries(draw PRIVATE libreweb-browser-lib-draw ${GTKMM_LIBRARIES} LibCommonMarker gtest_main gmock_main)
+add_test(NAME draw_test COMMAND draw)
+
+add_executable(file file_test.cc)
+target_include_directories(file PRIVATE ${CMAKE_SOURCE_DIR}/src)
+target_link_libraries(file PRIVATE libreweb-browser-lib-file gtest_main)
+add_test(NAME file_test COMMAND file)
+
+add_executable(parser parser_test.cc)
+target_include_directories(parser PRIVATE ${CMAKE_SOURCE_DIR}/src ${CMARK_BINARY_DIR}  ${GTKMM_INCLUDE_DIRS})
+target_link_libraries(parser PRIVATE libreweb-browser-lib-parser ${GTKMM_LIBRARIES} LibCommonMarker gtest_main)
+add_test(NAME parser_test COMMAND parser)
+
+# Add target that runs all unit-tests
+# The unit tests are running in xvfb (virtual frame buffer), allowing us
+# to use GTK widgets.
+add_custom_target(tests ALL
+  COMMAND xvfb-run env GTEST_COLOR=1 ${CMAKE_CTEST_COMMAND} --verbose --output-on-failure
+  DEPENDS draw file parser
+  WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/tst
+  COMMENT "Execute all unit-tests"
+  VERBATIM
+)
diff --git a/tst/draw_test.cc b/tst/draw_test.cc
new file mode 100644
index 0000000..4a8c00f
--- /dev/null
+++ b/tst/draw_test.cc
@@ -0,0 +1,160 @@
+#include "draw.h"
+#include "md-parser.h"
+#include "mock-middleware.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include <gtkmm/application.h>
+#include <string>
+namespace
+{
+  class DrawFixture : public testing::Test
+  {
+  protected:
+    void SetUp() override
+    {
+      Gtk::Application::create();
+    }
+  };
+
+  TEST_F(DrawFixture, TestDrawSetText)
+  {
+    // Given
+    std::string text = "Hello world!";
+    MockMiddleware middleware;
+    Draw draw(middleware);
+
+    // When
+    draw.setText(text);
+
+    // Then
+    ASSERT_EQ(draw.getText(), text);
+  }
+
+  TEST_F(DrawFixture, TestDrawDocument)
+  {
+    // Given
+    std::string markdown = "**Hello** *world*";
+    cmark_node* doc = Parser::parseContent(markdown);
+
+    MockMiddleware middleware;
+    Draw draw(middleware);
+
+    // When
+    draw.setDocument(doc);
+
+    // Then
+    std::string result = draw.getText();
+    ASSERT_EQ(result, "Hello world\n\n");
+  }
+
+  TEST_F(DrawFixture, TestDrawTextTags)
+  {
+    // Given
+    std::string italicTagName = "italic";
+    std::string boldTagName = "bold";
+    std::string heading1TagName = "heading1";
+    std::string heading2TagName = "heading2";
+    std::string heading3TagName = "heading3";
+    std::string heading4TagName = "heading4";
+    std::string heading5TagName = "heading5";
+    std::string heading6TagName = "heading6";
+    std::string strikethroughTagName = "strikethrough";
+    std::string superscriptTagName = "superscript";
+    std::string subscriptTagName = "subscript";
+    std::string codeTagName = "code";
+    std::string quoteTagName = "quote";
+    std::string highlightTagName = "highlight";
+    MockMiddleware middleware;
+    Draw draw(middleware);
+
+    // When
+    auto tagTable = draw.get_buffer()->get_tag_table();
+    auto properyItalic = tagTable->lookup(italicTagName);
+    auto properyBold = tagTable->lookup(boldTagName);
+    auto properyHeading1 = tagTable->lookup(heading1TagName);
+    auto properyHeading2 = tagTable->lookup(heading2TagName);
+    auto properyHeading3 = tagTable->lookup(heading3TagName);
+    auto properyHeading4 = tagTable->lookup(heading4TagName);
+    auto properyHeading5 = tagTable->lookup(heading5TagName);
+    auto properyHeading6 = tagTable->lookup(heading6TagName);
+    auto properyStrikethrough = tagTable->lookup(strikethroughTagName);
+    auto properySuperscript = tagTable->lookup(superscriptTagName);
+    auto properySubscript = tagTable->lookup(subscriptTagName);
+    auto properyCode = tagTable->lookup(codeTagName);
+    auto properyQuote = tagTable->lookup(quoteTagName);
+    auto properyHighlight = tagTable->lookup(highlightTagName);
+
+    // Then
+    ASSERT_NE(properyItalic.get(), nullptr);
+    ASSERT_EQ(properyItalic->property_name().get_value(), italicTagName);
+    ASSERT_NE(properyBold.get(), nullptr);
+    ASSERT_EQ(properyBold->property_name().get_value(), boldTagName);
+    ASSERT_NE(properyHeading1.get(), nullptr);
+    ASSERT_EQ(properyHeading1->property_name().get_value(), heading1TagName);
+    ASSERT_NE(properyHeading2.get(), nullptr);
+    ASSERT_EQ(properyHeading2->property_name().get_value(), heading2TagName);
+    ASSERT_NE(properyHeading3.get(), nullptr);
+    ASSERT_EQ(properyHeading3->property_name().get_value(), heading3TagName);
+    ASSERT_NE(properyHeading4.get(), nullptr);
+    ASSERT_EQ(properyHeading4->property_name().get_value(), heading4TagName);
+    ASSERT_NE(properyHeading5.get(), nullptr);
+    ASSERT_EQ(properyHeading5->property_name().get_value(), heading5TagName);
+    ASSERT_NE(properyHeading6.get(), nullptr);
+    ASSERT_EQ(properyHeading6->property_name().get_value(), heading6TagName);
+    ASSERT_NE(properyStrikethrough.get(), nullptr);
+    ASSERT_EQ(properyStrikethrough->property_name().get_value(), strikethroughTagName);
+    ASSERT_NE(properySuperscript.get(), nullptr);
+    ASSERT_EQ(properySuperscript->property_name().get_value(), superscriptTagName);
+    ASSERT_NE(properySubscript.get(), nullptr);
+    ASSERT_EQ(properySubscript->property_name().get_value(), subscriptTagName);
+    ASSERT_NE(properyCode.get(), nullptr);
+    ASSERT_EQ(properyCode->property_name().get_value(), codeTagName);
+    ASSERT_NE(properyQuote.get(), nullptr);
+    ASSERT_EQ(properyQuote->property_name().get_value(), quoteTagName);
+    ASSERT_NE(properyHighlight.get(), nullptr);
+    ASSERT_EQ(properyHighlight->property_name().get_value(), highlightTagName);
+  }
+
+  TEST_F(DrawFixture, TestDrawTextAttributes)
+  {
+    // Given
+    std::string markdown = "**bold**~~strikethrough~~^up^%down%`code`";
+    gsize length = 0;
+    cmark_node* doc = Parser::parseContent(markdown);
+    MockMiddleware middleware;
+    Draw draw(middleware);
+
+    // When
+    draw.setDocument(doc);
+    auto buffer = draw.get_buffer();
+    // Using the built-in formatter
+    guint8* data = buffer->serialize(buffer, "application/x-gtk-text-buffer-rich-text", buffer->begin(), buffer->end(), length);
+    // Convert data to string
+    std::string stringData(data, data + length);
+
+    // Then
+    // Bold attribute
+    std::string expectAttr1 = "<attr name=\"weight\" type=\"gint\" value=\"700\" />";
+    // Strikethrough attribute
+    std::string expectAttr2 = "<attr name=\"strikethrough\" type=\"gboolean\" value=\"TRUE\" />";
+    // Super-/subcript attribute
+    std::string expectAttr3 =
+        "<attr name=\"scale\" type=\"gdouble\" value="; // Depending on platform the value could be in UK or US format (so we removed the value)
+    // Superscript attributes
+    std::string expectAttr4 = "<attr name=\"rise\" type=\"gint\" value=\"-6144\" />";
+    // Subscript attributes
+    std::string expectAttr5 = "<attr name=\"rise\" type=\"gint\" value=\"6144\" />";
+    // Code attributes
+    std::string expectAttr6 = "<attr name=\"background-gdk\" type=\"GdkColor\" value=\"e0e0:e0e0:e0e0\" />";
+    std::string expectAttr7 = "<attr name=\"foreground-gdk\" type=\"GdkColor\" value=\"3232:3232:3232\" />";
+    std::string expectAttr8 = "<attr name=\"family\" type=\"gchararray\" value=\"monospace\" />";
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr1));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr2));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr3));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr4));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr5));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr6));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr7));
+    EXPECT_THAT(stringData, testing::HasSubstr(expectAttr8));
+  }
+} // namespace
diff --git a/tst/file_test.cc b/tst/file_test.cc
new file mode 100644
index 0000000..1cb98d5
--- /dev/null
+++ b/tst/file_test.cc
@@ -0,0 +1,16 @@
+#include "file.h"
+#include "gtest/gtest.h"
+#include <string>
+namespace
+{
+  TEST(LibreWebTest, TestGetFilename)
+  {
+    // Given
+    std::string path = "/path/to/a/filename.sh";
+    std::string expectedFilename = "filename.sh";
+    // When
+    std::string filename = File::getFilename(path);
+    // Then
+    ASSERT_EQ(filename, expectedFilename);
+  }
+} // namespace
\ No newline at end of file
diff --git a/tst/mock-middleware.h b/tst/mock-middleware.h
new file mode 100644
index 0000000..a96393d
--- /dev/null
+++ b/tst/mock-middleware.h
@@ -0,0 +1,28 @@
+#include "middleware-i.h"
+#include "gmock/gmock.h"
+#include <string>
+
+struct cmark_node;
+
+class MockMiddleware : public MiddlewareInterface
+{
+public:
+  MOCK_METHOD(void,
+              doRequest,
+              (const std::string& path, bool isSetAddressBar, bool isHistoryRequest, bool isDisableEditor, bool isParseContent),
+              (override));
+  MOCK_METHOD(std::string, doAdd, (const std::string& path), (override));
+  MOCK_METHOD(void, doWrite, (const std::string& path, bool isSetAddressAndTitle), (override));
+  MOCK_METHOD(void, setContent, (const Glib::ustring& content), (override));
+  MOCK_METHOD(Glib::ustring, getContent, (), (const, override));
+  MOCK_METHOD(cmark_node*, parseContent, (), (const, override));
+  MOCK_METHOD(void, resetContentAndPath, (), (override));
+  MOCK_METHOD(std::size_t, getIPFSNumberOfPeers, (), (const, override));
+  MOCK_METHOD(int, getIPFSRepoSize, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSRepoPath, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSIncomingRate, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSOutcomingRate, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSVersion, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSClientId, (), (const, override));
+  MOCK_METHOD(std::string, getIPFSClientPublicKey, (), (const, override));
+};
diff --git a/tst/parser_test.cc b/tst/parser_test.cc
new file mode 100644
index 0000000..530936b
--- /dev/null
+++ b/tst/parser_test.cc
@@ -0,0 +1,50 @@
+#include "md-parser.h"
+#include "gtest/gtest.h"
+#include <cmark-gfm.h>
+#include <node.h>
+#include <string>
+namespace
+{
+  TEST(LibreWebTest, TestContentParser)
+  {
+    // Given
+    std::string markdown = "Jaja";
+    uint16_t expectedDocument = CMARK_NODE_DOCUMENT;
+
+    // When
+    cmark_node* doc = Parser::parseContent(markdown);
+
+    // Then
+    ASSERT_EQ(doc->type, expectedDocument);
+    cmark_node_free(doc);
+  }
+
+  TEST(LibreWebTest, TestHTMLRender)
+  {
+    // Given
+    std::string markdown = "_Italic_ **BOLD** ~~strike~~";
+    std::string expectedHtml = "<p><em>Italic</em> <strong>BOLD</strong> <del>strike</del></p>\n";
+
+    // When
+    cmark_node* doc = Parser::parseContent(markdown);
+    std::string html = Parser::renderHTML(doc);
+    cmark_node_free(doc);
+
+    // Then
+    ASSERT_EQ(html, expectedHtml);
+  }
+
+  TEST(LibreWebTest, TestMarkdownRender)
+  {
+    // Given
+    std::string markdown = "**HOLA**";
+
+    // When
+    cmark_node* doc = Parser::parseContent(markdown);
+    std::string markdownAgain = Parser::renderMarkdown(doc);
+    cmark_node_free(doc);
+
+    // Then
+    ASSERT_EQ(markdownAgain, markdown + "\n");
+  }
+} // namespace
\ No newline at end of file