fix: skip clipboard tests when no display available

Author: nikolay-e

.github/workflows/ci.yml

@@ -114,22 +114,11 @@ jobs:
           python -m pip install --upgrade pip
           pip install -e .[dev]
 
-      - name: Install clipboard tools (Linux)
-        if: runner.os == 'Linux'
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y xvfb xclip
-
       - name: Run Tests with Coverage
         shell: bash
         run: |
-          if [ "$RUNNER_OS" = "Linux" ]; then
-            xvfb-run pytest -v --cov=src/treemapper --cov-report=xml \
-              --cov-report=term-missing --cov-branch --junitxml=test-results.xml
-          else
-            pytest -v --cov=src/treemapper --cov-report=xml \
-              --cov-report=term-missing --cov-branch --junitxml=test-results.xml
-          fi
+          pytest -v --cov=src/treemapper --cov-report=xml \
+            --cov-report=term-missing --cov-branch --junitxml=test-results.xml
 
       - name: Coverage report with threshold
         if: runner.os == 'Linux' && matrix.python-version == '3.12'
@@ -190,14 +179,9 @@ jobs:
           pip install -e .
           pip install pytest pytest-cov
 
-      - name: Install clipboard tools (Linux)
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y xvfb xclip
-
       - name: Run Tests
         run: |
-          xvfb-run pytest -v
+          pytest -v
 
   # ============================================================================
   # Mutation Testing (test effectiveness validation)

tests/test_clipboard.py

@@ -164,6 +164,10 @@ def test_copy_flag_accepted(self, temp_project):
         result = run_treemapper_subprocess([".", "-c"], cwd=temp_project)
         assert result.returncode == 0
 
+    @pytest.mark.skipif(
+        not clipboard_available(),
+        reason="Clipboard not available (no display or clipboard tool)"
+    )
     def test_copy_suppresses_stdout(self, temp_project):
         result = run_treemapper_subprocess([".", "-c"], cwd=temp_project)
         assert result.returncode == 0
@@ -207,6 +211,10 @@ def test_explicit_stdout_without_copy(self, temp_project):
         assert result.stdout != ""
         assert "file.txt" in result.stdout
 
+    @pytest.mark.skipif(
+        not clipboard_available(),
+        reason="Clipboard not available (no display or clipboard tool)"
+    )
     def test_copy_without_explicit_stdout_suppresses_output(self, temp_project):
         """Test that -c without -o - suppresses stdout when clipboard succeeds."""
         result = run_treemapper_subprocess([".", "-c"], cwd=temp_project)