completions: test validity of shell completion files

CI: install zsh and fish so we can test shell completions

.github/workflows/ci.yml

@@ -97,6 +97,7 @@ jobs:
         sudo apt-get install -y libssl-dev libacl1-dev libxxhash-dev liblz4-dev libzstd-dev
         sudo apt-get install -y libfuse-dev fuse || true  # Required for Python llfuse module
         sudo apt-get install -y libfuse3-dev fuse3 || true  # Required for Python pyfuse3 module
+        sudo apt-get install -y bash zsh fish  # for shell completion tests
 
     - name: Install Python requirements
       run: |

src/borg/testsuite/shell_completions_test.py

@@ -0,0 +1,55 @@
+import os
+import subprocess
+import pytest
+
+SHELL_COMPLETIONS_DIR = os.path.join(os.path.dirname(__file__), "..", "..", "..", "scripts", "shell_completions")
+
+
+def test_bash_completion_is_valid():
+    """Test that the bash completion file is valid bash syntax."""
+    bash_completion_file = os.path.join(SHELL_COMPLETIONS_DIR, "bash", "borg")
+    assert os.path.isfile(bash_completion_file)
+
+    # Check if bash is available
+    try:
+        subprocess.run(["bash", "--version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
+    except (subprocess.SubprocessError, FileNotFoundError):
+        pytest.skip("bash not available")
+
+    # Test if the bash completion file can be sourced without errors
+    result = subprocess.run(["bash", "-n", bash_completion_file], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    assert result.returncode == 0, f"Bash completion file has syntax errors: {result.stderr.decode()}"
+
+
+def test_fish_completion_is_valid():
+    """Test that the fish completion file is valid fish syntax."""
+    fish_completion_file = os.path.join(SHELL_COMPLETIONS_DIR, "fish", "borg.fish")
+    assert os.path.isfile(fish_completion_file)
+
+    # Check if fish is available
+    try:
+        subprocess.run(["fish", "--version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
+    except (subprocess.SubprocessError, FileNotFoundError):
+        pytest.skip("fish not available")
+
+    # Test if the fish completion file can be sourced without errors
+    result = subprocess.run(
+        ["fish", "-c", f"source {fish_completion_file}"], stdout=subprocess.PIPE, stderr=subprocess.PIPE
+    )
+    assert result.returncode == 0, f"Fish completion file has syntax errors: {result.stderr.decode()}"
+
+
+def test_zsh_completion_is_valid():
+    """Test that the zsh completion file is valid zsh syntax."""
+    zsh_completion_file = os.path.join(SHELL_COMPLETIONS_DIR, "zsh", "_borg")
+    assert os.path.isfile(zsh_completion_file)
+
+    # Check if zsh is available
+    try:
+        subprocess.run(["zsh", "--version"], stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True)
+    except (subprocess.SubprocessError, FileNotFoundError):
+        pytest.skip("zsh not available")
+
+    # Test if the zsh completion file can be sourced without errors
+    result = subprocess.run(["zsh", "-n", zsh_completion_file], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    assert result.returncode == 0, f"Zsh completion file has syntax errors: {result.stderr.decode()}"