chore: Add unit tests for DocumentContextReader (#90)

chore: Add unit tests for DocumentContextReader

The tests are based on GTest like some tests in Qt Creator itself, which
makes it easy to run as full Qt Creator does not need to be started.

.github/workflows/build_cmake.yml

@@ -70,7 +70,7 @@ jobs:
         cmakeVersion: ${{ env.CMAKE_VERSION }}
         ninjaVersion: ${{ env.NINJA_VERSION }}
 
-    - name: Install system libs
+    - name: Install dependencies
       shell: cmake -P {0}
       run: |
         if ("${{ runner.os }}" STREQUAL "Linux")
@@ -78,7 +78,13 @@ jobs:
             COMMAND sudo apt update
           )
           execute_process(
-            COMMAND sudo apt install libgl1-mesa-dev
+            COMMAND sudo apt install
+              # build dependencies
+              libgl1-mesa-dev libgtest-dev
+              # runtime dependencies for tests (Qt is downloaded outside package manager,
+              # thus minimal dependencies must be installed explicitly)
+              libsecret-1-0 libxcb-cursor0 libxcb-icccm4 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-render0
+              libxcb-shape0 libxcb-shm0 libxcb-sync1 libxcb-xfixes0 libxcb-xkb1 libxkbcommon-x11-0 xvfb
             RESULT_VARIABLE result
           )
           if (NOT result EQUAL 0)
@@ -258,6 +264,11 @@ jobs:
         name: ${{ env.PLUGIN_NAME }}-origin-json
         path: ./build/build/${{ env.PLUGIN_NAME }}.json
 
+    - name: Run unit tests
+      if: matrix.config.os == 'ubuntu-latest'
+      run: |
+        xvfb-run ./build/build/test/QodeAssistTest
+
   update_json:
     if: contains(github.ref, 'tags/v')
     runs-on: ubuntu-latest