fix: false positive on verify_install script being external shell (#1704)

- Introduced a new test script for shell detection logic in
`verify_install.sh`.
- Updated the `package.json` to include a new test command for shell
detection.
- Enhanced the `verify_install.sh` script to accurately check the
current shell interpreter using `/proc` and fallback methods.

This improves the testing framework and ensures better validation of
shell detection functionality.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- Bug Fixes
- Installer now detects the actual interpreter more robustly and
strictly requires Bash; non-Bash environments produce clear error
messages and abort installation.
- Tests
- Added automated shell-detection tests to validate behavior across
environments.
- Test suite expanded to run the new shell-detection checks as part of
the standard test command.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

plugin/package.json

@@ -33,8 +33,9 @@
     "env:validate": "test -f .env || (echo 'Error: .env file missing. Run npm run env:init first' && exit 1)",
     "env:clean": "rm -f .env",
     "// Testing": "",
-    "test": "vitest && pnpm run test:extractor",
-    "test:extractor": "bash ./tests/test-extractor.sh"
+    "test": "vitest && pnpm run test:extractor && pnpm run test:shell-detection",
+    "test:extractor": "bash ./tests/test-extractor.sh",
+    "test:shell-detection": "bash ./tests/test-shell-detection.sh"
   },
   "devDependencies": {
     "http-server": "14.1.1",

plugin/source/dynamix.unraid.net/usr/local/share/dynamix.unraid.net/install/scripts/verify_install.sh

@@ -6,11 +6,19 @@
 check_shell() {
   # This script runs with #!/bin/bash shebang
   # On Unraid, users may configure bash to load other shells through .bashrc
-  # We check if the current process ($$) is actually bash, not another shell
-  # Using $$ is correct here - we need to detect if THIS process is running the expected bash
+  # We need to check if the interpreter running this script is actually bash
+  # Use readlink on /proc to find the actual interpreter, not the script name
   local current_shell
-  current_shell=$(ps -o comm= -p $$)
-  
+
+  # Get the actual interpreter from /proc
+  if [ -e "/proc/$$/exe" ]; then
+    current_shell=$(readlink "/proc/$$/exe")
+  else
+    # Fallback to checking the current process if /proc isn't available
+    # Note: This may return the script name on some systems
+    current_shell=$(ps -o comm= -p $$)
+  fi
+
   # Remove any path and get just the shell name
   current_shell=$(basename "$current_shell")
   

plugin/tests/test-shell-detection.sh

@@ -0,0 +1,159 @@
+#!/bin/bash
+# Test script for shell detection logic in verify_install.sh
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+VERIFY_SCRIPT="$SCRIPT_DIR/../source/dynamix.unraid.net/usr/local/share/dynamix.unraid.net/install/scripts/verify_install.sh"
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Test counter
+TESTS_RUN=0
+TESTS_PASSED=0
+
+# Helper function to run a test
+run_test() {
+    local test_name="$1"
+    local test_cmd="$2"
+    local expected_result="$3"
+
+    TESTS_RUN=$((TESTS_RUN + 1))
+
+    echo -n "Testing: $test_name ... "
+
+    # Run the test and capture exit code
+    set +e
+    output=$($test_cmd 2>&1)
+    result=$?
+    set -e
+
+    if [ "$result" -eq "$expected_result" ]; then
+        echo -e "${GREEN}PASS${NC}"
+        TESTS_PASSED=$((TESTS_PASSED + 1))
+    else
+        echo -e "${RED}FAIL${NC}"
+        echo "  Expected exit code: $expected_result, Got: $result"
+        echo "  Output: $output"
+    fi
+}
+
+# Extract just the check_shell function from verify_install.sh
+extract_check_shell() {
+    cat << 'EOF'
+#!/bin/bash
+check_shell() {
+  # This script runs with #!/bin/bash shebang
+  # On Unraid, users may configure bash to load other shells through .bashrc
+  # We need to check if the interpreter running this script is actually bash
+  # Use readlink on /proc to find the actual interpreter, not the script name
+  local current_shell
+
+  # Get the actual interpreter from /proc
+  if [ -e "/proc/$$/exe" ]; then
+    current_shell=$(readlink "/proc/$$/exe")
+  else
+    # Fallback to checking the current process if /proc isn't available
+    # Note: This may return the script name on some systems
+    current_shell=$(ps -o comm= -p $$)
+  fi
+
+  # Remove any path and get just the shell name
+  current_shell=$(basename "$current_shell")
+
+  if [[ "$current_shell" != "bash" ]]; then
+    echo "Unsupported shell detected: $current_shell" >&2
+    echo "Unraid scripts require bash but your system is configured to use $current_shell for scripts." >&2
+    echo "This can cause infinite loops or unexpected behavior when Unraid scripts execute." >&2
+    echo "Please configure $current_shell to only activate for interactive shells." >&2
+    echo "Add this check to your ~/.bashrc or /etc/profile before starting $current_shell:" >&2
+    echo "  [[ \$- == *i* ]] && exec $current_shell" >&2
+    echo "This ensures $current_shell only starts for interactive sessions, not scripts." >&2
+    exit 1
+  fi
+}
+check_shell
+EOF
+}
+
+echo "=== Shell Detection Tests ==="
+echo
+
+# Test 1: Running with bash should succeed
+echo "Test 1: Direct bash execution"
+TEMP_SCRIPT=$(mktemp)
+extract_check_shell > "$TEMP_SCRIPT"
+chmod +x "$TEMP_SCRIPT"
+run_test "Bash interpreter (should pass)" "bash $TEMP_SCRIPT" 0
+rm -f "$TEMP_SCRIPT"
+
+# Test 2: Check that the actual verify_install.sh script works with bash
+echo "Test 2: Verify install script with bash"
+if [ -f "$VERIFY_SCRIPT" ]; then
+    # Create a modified version that only runs check_shell
+    TEMP_VERIFY=$(mktemp)
+    sed -n '1,/^check_shell$/p' "$VERIFY_SCRIPT" > "$TEMP_VERIFY"
+    echo "exit 0" >> "$TEMP_VERIFY"
+    chmod +x "$TEMP_VERIFY"
+    run_test "Verify install script shell check" "bash $TEMP_VERIFY" 0
+    rm -f "$TEMP_VERIFY"
+else
+    echo -e "${YELLOW}SKIP${NC} - verify_install.sh not found"
+fi
+
+# Test 3: Simulate non-bash shell (if available)
+echo "Test 3: Non-bash shell simulation"
+if command -v sh >/dev/null 2>&1 && [ "$(readlink -f "$(command -v sh)")" != "$(readlink -f "$(command -v bash)")" ]; then
+    TEMP_SCRIPT=$(mktemp)
+    # Create a test that will fail if sh is detected
+    cat << 'EOF' > "$TEMP_SCRIPT"
+#!/bin/sh
+# This simulates what would happen if a non-bash shell was detected
+current_shell=$(basename "$(readlink -f /proc/$$/exe 2>/dev/null || echo sh)")
+if [ "$current_shell" != "bash" ]; then
+    echo "Detected non-bash shell: $current_shell" >&2
+    exit 1
+fi
+exit 0
+EOF
+    chmod +x "$TEMP_SCRIPT"
+    run_test "Non-bash shell detection" "sh $TEMP_SCRIPT" 1
+    rm -f "$TEMP_SCRIPT"
+else
+    echo -e "${YELLOW}SKIP${NC} - sh not available or is symlinked to bash"
+fi
+
+# Test 4: Check /proc availability (informational only, not a failure)
+echo "Test 4: /proc filesystem check"
+if [ -e "/proc/$$/exe" ]; then
+    echo -e "${GREEN}INFO${NC} - /proc filesystem is available"
+else
+    echo -e "${YELLOW}INFO${NC} - /proc filesystem not available, fallback to ps will be used"
+fi
+
+# Test 5: Verify the script name is not detected as shell
+echo "Test 5: Script name not detected as shell"
+TEMP_SCRIPT=$(mktemp -t verify_install.XXXXXX)
+extract_check_shell > "$TEMP_SCRIPT"
+chmod +x "$TEMP_SCRIPT"
+# This should pass because it's still bash, even though the script is named verify_install
+run_test "Script named verify_install (should still pass)" "bash $TEMP_SCRIPT" 0
+rm -f "$TEMP_SCRIPT"
+
+echo
+echo "=== Test Summary ==="
+echo "Tests run: $TESTS_RUN"
+echo "Tests passed: $TESTS_PASSED"
+echo "Tests failed: $((TESTS_RUN - TESTS_PASSED))"
+
+if [ "$TESTS_PASSED" -eq "$TESTS_RUN" ]; then
+    echo -e "${GREEN}All tests passed!${NC}"
+    exit 0
+else
+    echo -e "${RED}Some tests failed${NC}"
+    exit 1
+fi