diff --git a/tests/test_apa.bats b/tests/test_apa.bats
new file mode 100644
index 000000000..ab7bc4007
--- /dev/null
+++ b/tests/test_apa.bats
@@ -0,0 +1,401 @@
+#!/usr/bin/env bats
+
+# Load the apa script for testing
+APA_SCRIPT="${BATS_TEST_DIRNAME}/../git/extensions/apa.sh"
+
+setup() {
+    # Create temporary directory for test isolation
+    export TEST_TEMP_DIR="$(mktemp -d)"
+    export ORIGINAL_HOME="$HOME"
+    export ORIGINAL_APA_CONFIG_DIR="$APA_CONFIG_DIR"
+    export ORIGINAL_APA_LOG_LEVEL="$APA_LOG_LEVEL"
+    export ORIGINAL_APA_TIMEOUT="$APA_TIMEOUT"
+
+    # Set up test environment
+    export HOME="$TEST_TEMP_DIR"
+    export APA_CONFIG_DIR="$TEST_TEMP_DIR/.apa"
+    export APA_LOG_LEVEL="quiet"
+    export APA_TIMEOUT="10"
+
+    # Make apa script executable and available
+    chmod +x "$APA_SCRIPT"
+    export PATH="$(dirname "$APA_SCRIPT"):$PATH"
+}
+
+teardown() {
+    # Restore original environment
+    export HOME="$ORIGINAL_HOME"
+    export APA_CONFIG_DIR="$ORIGINAL_APA_CONFIG_DIR"
+    export APA_LOG_LEVEL="$ORIGINAL_APA_LOG_LEVEL"
+    export APA_TIMEOUT="$ORIGINAL_APA_TIMEOUT"
+
+    # Clean up temporary files
+    [ -n "$TEST_TEMP_DIR" ] && rm -rf "$TEST_TEMP_DIR"
+}
+
+@test "apa script exists and is executable" {
+    [ -f "$APA_SCRIPT" ]
+    [ -x "$APA_SCRIPT" ]
+}
+
+@test "apa shows help with --help option" {
+    run bash "$APA_SCRIPT" --help
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "apa - Automated Package Assistant" ]]
+    [[ "$output" =~ "Usage:" ]]
+    [[ "$output" =~ "Commands:" ]]
+    [[ "$output" =~ "install" ]]
+    [[ "$output" =~ "update" ]]
+    [[ "$output" =~ "remove" ]]
+}
+
+@test "apa shows help with -h option" {
+    run bash "$APA_SCRIPT" -h
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "apa - Automated Package Assistant" ]]
+}
+
+@test "apa shows version with --version option" {
+    run bash "$APA_SCRIPT" --version
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "apa version 1.2.3" ]]
+}
+
+@test "apa shows version with -v option" {
+    run bash "$APA_SCRIPT" -v
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "apa version 1.2.3" ]]
+}
+
+@test "apa shows help when run with no arguments" {
+    run bash "$APA_SCRIPT"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Usage:" ]]
+}
+
+@test "apa install succeeds with valid package name" {
+    run bash "$APA_SCRIPT" install nginx
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Package nginx installed successfully" ]]
+}
+
+@test "apa install creates config directory" {
+    bash "$APA_SCRIPT" install test-package
+    [ -d "$APA_CONFIG_DIR" ]
+}
+
+@test "apa install fails without package name" {
+    run bash "$APA_SCRIPT" install
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Install command requires a package name" ]]
+}
+
+@test "apa install fails with empty package name" {
+    run bash "$APA_SCRIPT" install ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Package name cannot be empty" ]]
+}
+
+@test "apa install fails with invalid package name containing spaces" {
+    run bash "$APA_SCRIPT" install "invalid package"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa install fails with invalid package name containing special chars" {
+    run bash "$APA_SCRIPT" install "invalid@package#"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa install accepts valid package names with dots, dashes, underscores" {
+    run bash "$APA_SCRIPT" install "valid-package_name.123"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "installed successfully" ]]
+}
+
+@test "apa update succeeds with valid package name" {
+    run bash "$APA_SCRIPT" update nginx
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Package nginx updated successfully" ]]
+}
+
+@test "apa update fails without package name" {
+    run bash "$APA_SCRIPT" update
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Update command requires a package name" ]]
+}
+
+@test "apa update fails with empty package name" {
+    run bash "$APA_SCRIPT" update ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Package name cannot be empty" ]]
+}
+
+@test "apa update fails with invalid package name" {
+    run bash "$APA_SCRIPT" update "invalid@package"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa remove succeeds with valid package name" {
+    run bash "$APA_SCRIPT" remove nginx
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Package nginx removed successfully" ]]
+}
+
+@test "apa remove fails without package name" {
+    run bash "$APA_SCRIPT" remove
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Remove command requires a package name" ]]
+}
+
+@test "apa remove fails with empty package name" {
+    run bash "$APA_SCRIPT" remove ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Package name cannot be empty" ]]
+}
+
+@test "apa remove fails with invalid package name" {
+    run bash "$APA_SCRIPT" remove "invalid package name"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa list shows installed packages" {
+    run bash "$APA_SCRIPT" list
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "nginx-1.18.0" ]]
+    [[ "$output" =~ "curl-7.68.0" ]]
+    [[ "$output" =~ "git-2.34.1" ]]
+}
+
+@test "apa search succeeds with valid query" {
+    run bash "$APA_SCRIPT" search "web"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Found packages matching 'web'" ]]
+    [[ "$output" =~ "web-server-toolkit" ]]
+}
+
+@test "apa search fails without query" {
+    run bash "$APA_SCRIPT" search
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Search command requires a query" ]]
+}
+
+@test "apa search fails with empty query" {
+    run bash "$APA_SCRIPT" search ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Search query cannot be empty" ]]
+}
+
+@test "apa search handles special characters in query" {
+    run bash "$APA_SCRIPT" search "web-server"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Found packages matching" ]]
+}
+
+@test "apa info succeeds with valid package name" {
+    run bash "$APA_SCRIPT" info nginx
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Package: nginx" ]]
+    [[ "$output" =~ "Version:" ]]
+    [[ "$output" =~ "Description:" ]]
+    [[ "$output" =~ "Maintainer:" ]]
+}
+
+@test "apa info fails without package name" {
+    run bash "$APA_SCRIPT" info
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Info command requires a package name" ]]
+}
+
+@test "apa info fails with empty package name" {
+    run bash "$APA_SCRIPT" info ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Package name cannot be empty" ]]
+}
+
+@test "apa info fails with invalid package name" {
+    run bash "$APA_SCRIPT" info "invalid@package"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa handles unknown command gracefully" {
+    run bash "$APA_SCRIPT" unknown-command
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Unknown command: unknown-command" ]]
+}
+
+@test "apa handles unknown option gracefully" {
+    run bash "$APA_SCRIPT" --unknown-option
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Unknown option: --unknown-option" ]]
+}
+
+@test "apa quiet option suppresses info output" {
+    run bash "$APA_SCRIPT" --quiet install test-package
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "installed successfully" ]]
+    # Info logs should be suppressed in quiet mode
+}
+
+@test "apa debug option enables debug output" {
+    export APA_LOG_LEVEL="debug"
+    run bash "$APA_SCRIPT" --debug install test-package
+    [ "$status" -eq 0 ]
+}
+
+@test "apa timeout option is accepted" {
+    run bash "$APA_SCRIPT" --timeout 60 --help
+    [ "$status" -eq 0 ]
+}
+
+@test "apa respects APA_CONFIG_DIR environment variable" {
+    export APA_CONFIG_DIR="$TEST_TEMP_DIR/custom-config"
+    bash "$APA_SCRIPT" install test-package
+    [ -d "$TEST_TEMP_DIR/custom-config" ]
+}
+
+@test "apa respects APA_LOG_LEVEL environment variable" {
+    export APA_LOG_LEVEL="debug"
+    run bash "$APA_SCRIPT" install test-package
+    [ "$status" -eq 0 ]
+}
+
+@test "apa respects APA_TIMEOUT environment variable" {
+    export APA_TIMEOUT="120"
+    run bash "$APA_SCRIPT" install test-package
+    [ "$status" -eq 0 ]
+}
+
+@test "apa handles very long package names gracefully" {
+    local long_name=$(printf 'a%.0s' {1..1000})
+    run bash "$APA_SCRIPT" install "$long_name"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa handles package names with only valid characters at boundary" {
+    # Test exactly valid characters
+    run bash "$APA_SCRIPT" install "a"
+    [ "$status" -eq 0 ]
+
+    run bash "$APA_SCRIPT" install "a-b_c.123"
+    [ "$status" -eq 0 ]
+
+    run bash "$APA_SCRIPT" install "123"
+    [ "$status" -eq 0 ]
+}
+
+@test "apa rejects command injection attempts" {
+    run bash "$APA_SCRIPT" install "; rm -rf /"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+
+    run bash "$APA_SCRIPT" install "$(whoami)"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+
+    run bash "$APA_SCRIPT" install "|cat /etc/passwd"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa handles unicode characters in package names" {
+    run bash "$APA_SCRIPT" install "测试包"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid package name" ]]
+}
+
+@test "apa handles null bytes in input" {
+    printf "test\0package" | run bash "$APA_SCRIPT" install
+    [ "$status" -eq 1 ]
+}
+
+@test "apa handles missing HOME directory" {
+    unset HOME
+    run bash "$APA_SCRIPT" install test-package
+    [ "$status" -eq 0 ]
+}
+
+@test "apa handles non-writable config directory parent" {
+    # This test may need to be skipped in some environments
+    if [[ "$EUID" -ne 0 ]]; then
+        export APA_CONFIG_DIR="/root/test-apa-config"
+        run bash "$APA_SCRIPT" install test-package
+        # Should handle gracefully, not necessarily succeed
+        [[ "$status" -eq 0 || "$status" -eq 1 ]]
+    else
+        skip "Cannot test non-writable directory as root"
+    fi
+}
+
+@test "apa operations complete within timeout" {
+    # Test that operations don't hang indefinitely
+    timeout 30s bash "$APA_SCRIPT" install test-package
+    [ $? -ne 124 ]  # 124 is timeout's exit code
+}
+
+@test "apa can handle multiple operations in sequence" {
+    run bash "$APA_SCRIPT" install package1
+    [ "$status" -eq 0 ]
+
+    run bash "$APA_SCRIPT" update package1
+    [ "$status" -eq 0 ]
+
+    run bash "$APA_SCRIPT" info package1
+    [ "$status" -eq 0 ]
+
+    run bash "$APA_SCRIPT" remove package1
+    [ "$status" -eq 0 ]
+}
+
+@test "apa output format is consistent across commands" {
+    # Test that all successful operations produce clean output
+    run bash "$APA_SCRIPT" install test-package
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ ^[[:print:][:space:]]*$ ]]
+
+    run bash "$APA_SCRIPT" list
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ ^[[:print:][:space:]]*$ ]]
+}
+
+@test "apa handles concurrent execution" {
+    # Run multiple instances to test for race conditions
+    bash "$APA_SCRIPT" install package1 &
+    bash "$APA_SCRIPT" install package2 &
+    bash "$APA_SCRIPT" list &
+
+    wait
+    [ $? -eq 0 ]
+}
+
+@test "apa config directory creation is idempotent" {
+    # First run should create directory
+    bash "$APA_SCRIPT" install test-package
+    [ -d "$APA_CONFIG_DIR" ]
+
+    # Second run should not fail even if directory exists
+    bash "$APA_SCRIPT" install test-package2
+    [ -d "$APA_CONFIG_DIR" ]
+}
+
+@test "apa validates package names consistently across commands" {
+    # Test that validation works the same for all commands that take package names
+    local invalid_name="invalid@package"
+
+    run bash "$APA_SCRIPT" install "$invalid_name"
+    [ "$status" -eq 1 ]
+
+    run bash "$APA_SCRIPT" update "$invalid_name"
+    [ "$status" -eq 1 ]
+
+    run bash "$APA_SCRIPT" remove "$invalid_name"
+    [ "$status" -eq 1 ]
+
+    run bash "$APA_SCRIPT" info "$invalid_name"
+    [ "$status" -eq 1 ]
+}
\ No newline at end of file
diff --git a/tests/test_distro_specific.bats b/tests/test_distro_specific.bats
new file mode 100644
index 000000000..891319550
--- /dev/null
+++ b/tests/test_distro_specific.bats
@@ -0,0 +1,731 @@
+#!/usr/bin/env bats
+
+# Test suite for distribution-specific functionality
+# Testing framework: BATS (Bash Automated Testing System)
+
+# Load test helpers if they exist
+load test_helper 2>/dev/null || true
+
+setup() {
+    # Create temporary directory for test fixtures
+    export BATS_TEST_TMPDIR="$(mktemp -d)"
+    export ORIGINAL_PATH="$PATH"
+    export ORIGINAL_ETC="/etc"
+    
+    # Create mock /etc directory structure
+    mkdir -p "$BATS_TEST_TMPDIR/etc"
+    
+    # Mock various distribution release files
+    create_mock_os_release() {
+        local distro="$1"
+        case "$distro" in
+            "ubuntu")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="Ubuntu"
+VERSION="20.04.3 LTS (Focal Fossa)"
+ID=ubuntu
+ID_LIKE=debian
+PRETTY_NAME="Ubuntu 20.04.3 LTS"
+VERSION_ID="20.04"
+VERSION_CODENAME=focal
+UBUNTU_CODENAME=focal
+EOF
+                ;;
+            "centos")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="CentOS Linux"
+VERSION="8"
+ID="centos"
+ID_LIKE="rhel fedora"
+VERSION_ID="8"
+PRETTY_NAME="CentOS Linux 8"
+ANSI_COLOR="0;31"
+CPE_NAME="cpe:/o:centos:centos:8"
+HOME_URL="https://www.centos.org/"
+BUG_REPORT_URL="https://bugs.centos.org/"
+EOF
+                ;;
+            "debian")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
+NAME="Debian GNU/Linux"
+VERSION_ID="11"
+VERSION="11 (bullseye)"
+VERSION_CODENAME=bullseye
+ID=debian
+HOME_URL="https://www.debian.org/"
+SUPPORT_URL="https://www.debian.org/support"
+BUG_REPORT_URL="https://bugs.debian.org/"
+EOF
+                ;;
+            "rhel")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="Red Hat Enterprise Linux"
+VERSION="8.5 (Ootpa)"
+ID="rhel"
+ID_LIKE="fedora"
+VERSION_ID="8.5"
+PLATFORM_ID="platform:el8"
+PRETTY_NAME="Red Hat Enterprise Linux 8.5 (Ootpa)"
+ANSI_COLOR="0;31"
+EOF
+                ;;
+            "fedora")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="Fedora Linux"
+VERSION="35 (Workstation Edition)"
+ID=fedora
+VERSION_ID=35
+VERSION_CODENAME=""
+PLATFORM_ID="platform:f35"
+PRETTY_NAME="Fedora Linux 35 (Workstation Edition)"
+ANSI_COLOR="0;38;2;60;110;180"
+EOF
+                ;;
+            "arch")
+                cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="Arch Linux"
+PRETTY_NAME="Arch Linux"
+ID=arch
+BUILD_ID=rolling
+ANSI_COLOR="38;2;23;147;209"
+HOME_URL="https://archlinux.org/"
+DOCUMENTATION_URL="https://wiki.archlinux.org/"
+SUPPORT_URL="https://bbs.archlinux.org/"
+BUG_REPORT_URL="https://bugs.archlinux.org/"
+EOF
+                ;;
+        esac
+    }
+    
+    # Mock LSB release file
+    create_mock_lsb_release() {
+        local distro="$1"
+        case "$distro" in
+            "ubuntu")
+                cat > "$BATS_TEST_TMPDIR/etc/lsb-release" << 'EOF'
+DISTRIB_ID=Ubuntu
+DISTRIB_RELEASE=20.04
+DISTRIB_CODENAME=focal
+DISTRIB_DESCRIPTION="Ubuntu 20.04.3 LTS"
+EOF
+                ;;
+        esac
+    }
+    
+    # Mock system commands
+    create_mock_commands() {
+        mkdir -p "$BATS_TEST_TMPDIR/bin"
+        export PATH="$BATS_TEST_TMPDIR/bin:$PATH"
+        
+        # Mock which command
+        cat > "$BATS_TEST_TMPDIR/bin/which" << 'EOF'
+#!/bin/bash
+case "$1" in
+    "apt"|"apt-get") echo "/usr/bin/apt" ;;
+    "yum") echo "/usr/bin/yum" ;;
+    "dnf") echo "/usr/bin/dnf" ;;
+    "pacman") echo "/usr/bin/pacman" ;;
+    "zypper") echo "/usr/bin/zypper" ;;
+    *) exit 1 ;;
+esac
+EOF
+        chmod +x "$BATS_TEST_TMPDIR/bin/which"
+    }
+}
+
+teardown() {
+    # Clean up test environment
+    rm -rf "$BATS_TEST_TMPDIR"
+    export PATH="$ORIGINAL_PATH"
+    unset BATS_TEST_TMPDIR ORIGINAL_PATH ORIGINAL_ETC
+}
+
+@test "should detect Ubuntu distribution correctly from os-release" {
+    create_mock_os_release "ubuntu"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "ubuntu" ]]
+}
+
+@test "should detect CentOS distribution correctly from os-release" {
+    create_mock_os_release "centos"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "centos" ]]
+}
+
+@test "should detect Debian distribution correctly from os-release" {
+    create_mock_os_release "debian"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "debian" ]]
+}
+
+@test "should detect RHEL distribution correctly from os-release" {
+    create_mock_os_release "rhel"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "rhel" ]]
+}
+
+@test "should detect Fedora distribution correctly from os-release" {
+    create_mock_os_release "fedora"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "fedora" ]]
+}
+
+@test "should detect Arch Linux distribution correctly from os-release" {
+    create_mock_os_release "arch"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 0 ]
+    [[ "$output" == "arch" ]]
+}
+
+@test "should detect apt package manager for Ubuntu" {
+    create_mock_os_release "ubuntu"
+    create_mock_commands
+    
+    get_package_manager() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            case "$ID" in
+                "ubuntu"|"debian") echo "apt" ;;
+                "centos"|"rhel") echo "yum" ;;
+                "fedora") echo "dnf" ;;
+                "arch") echo "pacman" ;;
+                "opensuse"|"sles") echo "zypper" ;;
+                *) echo "unknown" ;;
+            esac
+        fi
+    }
+    
+    run get_package_manager
+    [ "$status" -eq 0 ]
+    [[ "$output" == "apt" ]]
+}
+
+@test "should detect yum package manager for CentOS" {
+    create_mock_os_release "centos"
+    create_mock_commands
+    
+    get_package_manager() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            case "$ID" in
+                "ubuntu"|"debian") echo "apt" ;;
+                "centos"|"rhel") echo "yum" ;;
+                "fedora") echo "dnf" ;;
+                "arch") echo "pacman" ;;
+                "opensuse"|"sles") echo "zypper" ;;
+                *) echo "unknown" ;;
+            esac
+        fi
+    }
+    
+    run get_package_manager
+    [ "$status" -eq 0 ]
+    [[ "$output" == "yum" ]]
+}
+
+@test "should detect dnf package manager for Fedora" {
+    create_mock_os_release "fedora"
+    create_mock_commands
+    
+    get_package_manager() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            case "$ID" in
+                "ubuntu"|"debian") echo "apt" ;;
+                "centos"|"rhel") echo "yum" ;;
+                "fedora") echo "dnf" ;;
+                "arch") echo "pacman" ;;
+                "opensuse"|"sles") echo "zypper" ;;
+                *) echo "unknown" ;;
+            esac
+        fi
+    }
+    
+    run get_package_manager
+    [ "$status" -eq 0 ]
+    [[ "$output" == "dnf" ]]
+}
+
+@test "should detect pacman package manager for Arch Linux" {
+    create_mock_os_release "arch"
+    create_mock_commands
+    
+    get_package_manager() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            case "$ID" in
+                "ubuntu"|"debian") echo "apt" ;;
+                "centos"|"rhel") echo "yum" ;;
+                "fedora") echo "dnf" ;;
+                "arch") echo "pacman" ;;
+                "opensuse"|"sles") echo "zypper" ;;
+                *) echo "unknown" ;;
+            esac
+        fi
+    }
+    
+    run get_package_manager
+    [ "$status" -eq 0 ]
+    [[ "$output" == "pacman" ]]
+}
+
+@test "should handle missing os-release file gracefully" {
+    rm -f "$BATS_TEST_TMPDIR/etc/os-release"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        else
+            echo "Error: Unable to detect distribution - os-release not found"
+            return 1
+        fi
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Unable to detect distribution" ]]
+}
+
+@test "should handle malformed os-release file" {
+    cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+This is not a valid
+os-release file format
+ID=
+EOF
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            if [[ -z "$ID" ]]; then
+                echo "Error: Invalid distribution ID"
+                return 1
+            fi
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid distribution ID" ]]
+}
+
+@test "should handle unsupported distribution" {
+    cat > "$BATS_TEST_TMPDIR/etc/os-release" << 'EOF'
+NAME="Exotic Linux"
+ID="exotic"
+VERSION_ID="1.0"
+PRETTY_NAME="Exotic Linux 1.0"
+EOF
+    
+    get_package_manager() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            case "$ID" in
+                "ubuntu"|"debian") echo "apt" ;;
+                "centos"|"rhel") echo "yum" ;;
+                "fedora") echo "dnf" ;;
+                "arch") echo "pacman" ;;
+                "opensuse"|"sles") echo "zypper" ;;
+                *)
+                    echo "Error: Unsupported distribution: $ID"
+                    return 1
+                    ;;
+            esac
+        fi
+    }
+    
+    run get_package_manager
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Unsupported distribution: exotic" ]]
+}
+
+@test "should fall back to lsb-release when os-release is unavailable" {
+    rm -f "$BATS_TEST_TMPDIR/etc/os-release"
+    create_mock_lsb_release "ubuntu"
+    
+    detect_distribution_with_fallback() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+        elif [[ -f "$BATS_TEST_TMPDIR/etc/lsb-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/lsb-release"
+            echo "${DISTRIB_ID,,}"
+        else
+            echo "Error: Unable to detect distribution"
+            return 1
+        fi
+    }
+    
+    run detect_distribution_with_fallback
+    [ "$status" -eq 0 ]
+    [[ "$output" == "ubuntu" ]]
+}
+
+@test "should handle empty os-release file" {
+    touch "$BATS_TEST_TMPDIR/etc/os-release"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            if [[ -z "$ID" ]]; then
+                echo "Error: Distribution ID not found"
+                return 1
+            fi
+            echo "$ID"
+        fi
+    }
+    
+    run detect_distribution
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Distribution ID not found" ]]
+}
+
+@test "should validate distribution name parameter" {
+    validate_distribution_name() {
+        local distro="$1"
+        if [[ -z "$distro" ]]; then
+            echo "Error: Distribution name parameter is required"
+            return 1
+        fi
+        if [[ "$distro" =~ [^a-zA-Z0-9._-] ]]; then
+            echo "Error: Invalid characters in distribution name"
+            return 1
+        fi
+        echo "Valid distribution name: $distro"
+        return 0
+    }
+    
+    run validate_distribution_name ""
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "parameter is required" ]]
+}
+
+@test "should sanitize distribution names with special characters" {
+    validate_distribution_name() {
+        local distro="$1"
+        if [[ -z "$distro" ]]; then
+            echo "Error: Distribution name parameter is required"
+            return 1
+        fi
+        if [[ "$distro" =~ [^a-zA-Z0-9._-] ]]; then
+            echo "Error: Invalid characters in distribution name"
+            return 1
+        fi
+        echo "Valid distribution name: $distro"
+        return 0
+    }
+    
+    run validate_distribution_name "ubuntu; rm -rf /"
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Invalid characters" ]]
+}
+
+@test "should accept valid distribution names with hyphens and dots" {
+    validate_distribution_name() {
+        local distro="$1"
+        if [[ -z "$distro" ]]; then
+            echo "Error: Distribution name parameter is required"
+            return 1
+        fi
+        if [[ "$distro" =~ [^a-zA-Z0-9._-] ]]; then
+            echo "Error: Invalid characters in distribution name"
+            return 1
+        fi
+        echo "Valid distribution name: $distro"
+        return 0
+    }
+    
+    run validate_distribution_name "ubuntu-18.04"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Valid distribution name: ubuntu-18.04" ]]
+}
+
+@test "should accept distribution names with underscores" {
+    validate_distribution_name() {
+        local distro="$1"
+        if [[ -z "$distro" ]]; then
+            echo "Error: Distribution name parameter is required"
+            return 1
+        fi
+        if [[ "$distro" =~ [^a-zA-Z0-9._-] ]]; then
+            echo "Error: Invalid characters in distribution name"
+            return 1
+        fi
+        echo "Valid distribution name: $distro"
+        return 0
+    }
+    
+    run validate_distribution_name "centos_stream"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Valid distribution name: centos_stream" ]]
+}
+
+@test "should complete distribution detection within reasonable time" {
+    create_mock_os_release "ubuntu"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    run timeout 5s bash -c "detect_distribution"
+    [ "$status" -eq 0 ]
+    [[ "$output" == "ubuntu" ]]
+}
+
+@test "should handle concurrent distribution detection calls" {
+    create_mock_os_release "ubuntu"
+    
+    detect_distribution() {
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            echo "$ID"
+            return 0
+        fi
+        return 1
+    }
+    
+    local pids=()
+    for i in {1..3}; do
+        detect_distribution &
+        pids+=($!)
+    done
+    
+    local all_success=true
+    for pid in "${pids[@]}"; do
+        if ! wait "$pid"; then
+            all_success=false
+        fi
+    done
+    
+    [ "$all_success" = true ]
+}
+
+@test "should execute complete distribution-specific workflow for Ubuntu" {
+    create_mock_os_release "ubuntu"
+    create_mock_commands
+    
+    complete_distro_workflow() {
+        local distro package_manager
+        
+        if [[ -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            . "$BATS_TEST_TMPDIR/etc/os-release"
+            distro="$ID"
+        else
+            echo "Error: Cannot detect distribution"
+            return 1
+        fi
+        
+        case "$distro" in
+            "ubuntu"|"debian") package_manager="apt" ;;
+            "centos"|"rhel") package_manager="yum" ;;
+            "fedora") package_manager="dnf" ;;
+            "arch") package_manager="pacman" ;;
+            *) package_manager="unknown" ;;
+        esac
+        
+        echo "Distribution: $distro, Package Manager: $package_manager"
+        echo "Ubuntu workflow completed successfully"
+        return 0
+    }
+    
+    run complete_distro_workflow
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Distribution: ubuntu, Package Manager: apt" ]]
+    [[ "$output" =~ "Ubuntu workflow completed successfully" ]]
+}
+
+@test "should provide helpful error messages for failures" {
+    rm -f "$BATS_TEST_TMPDIR/etc/os-release"
+    
+    detect_distribution_with_helpful_errors() {
+        if [[ ! -f "$BATS_TEST_TMPDIR/etc/os-release" ]]; then
+            echo "Error: Unable to detect Linux distribution"
+            echo "Try: Ensure /etc/os-release exists and is readable"
+            echo "Alternative: Check for /etc/lsb-release or distribution-specific files"
+            return 1
+        fi
+    }
+    
+    run detect_distribution_with_helpful_errors
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Error: Unable to detect Linux distribution" ]]
+    [[ "$output" =~ "Try: Ensure /etc/os-release exists" ]]
+    [[ "$output" =~ "Alternative: Check for /etc/lsb-release" ]]
+}
+
+@test "should provide script version information" {
+    get_script_version() {
+        echo "distro_specific_utils v1.2.3"
+        return 0
+    }
+    
+    run get_script_version
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ [0-9]+\.[0-9]+\.[0-9]+ ]]
+}
+
+@test "should display comprehensive help information" {
+    display_help() {
+        cat << 'EOF'
+Usage: distro_specific_utils [OPTIONS] [COMMAND]
+
+DESCRIPTION:
+    Utility for detecting Linux distributions and managing 
+    distribution-specific operations.
+
+OPTIONS:
+    -h, --help      Show this help message
+    -v, --version   Show version information
+    -d, --detect    Detect current distribution
+    -p, --package   Show package manager for current distribution
+
+COMMANDS:
+    detect          Detect the current Linux distribution
+    package-mgr     Show the package manager for current distribution
+    
+EXAMPLES:
+    distro_specific_utils --detect
+    distro_specific_utils package-mgr
+
+SUPPORTED DISTRIBUTIONS:
+    Ubuntu, Debian, CentOS, RHEL, Fedora, Arch Linux, openSUSE
+EOF
+    }
+    
+    run display_help
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "Usage:" ]]
+    [[ "$output" =~ "OPTIONS:" ]]
+    [[ "$output" =~ "EXAMPLES:" ]]
+    [[ "$output" =~ "SUPPORTED DISTRIBUTIONS:" ]]
+}
+
+@test "should validate system requirements" {
+    check_system_requirements() {
+        local missing_commands=()
+        
+        if [[ ! -r /etc/os-release ]] && [[ ! -r /etc/lsb-release ]]; then
+            echo "Warning: No distribution identification files found"
+        fi
+        
+        for cmd in cat grep sed awk; do
+            if ! command -v "$cmd" >/dev/null 2>&1; then
+                missing_commands+=("$cmd")
+            fi
+        done
+        
+        if [[ ${#missing_commands[@]} -gt 0 ]]; then
+            echo "Error: Missing required commands: ${missing_commands[*]}"
+            return 1
+        fi
+        
+        echo "System requirements satisfied"
+        return 0
+    }
+    
+    export PATH="$BATS_TEST_TMPDIR/bin:$PATH"
+    for cmd in cat grep sed awk; do
+        echo '#!/bin/bash' > "$BATS_TEST_TMPDIR/bin/$cmd"
+        echo 'echo "mock $cmd"' >> "$BATS_TEST_TMPDIR/bin/$cmd"
+        chmod +x "$BATS_TEST_TMPDIR/bin/$cmd"
+    done
+    
+    run check_system_requirements
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "System requirements satisfied" ]]
+}
+
+@test "should handle insufficient permissions gracefully" {
+    touch "$BATS_TEST_TMPDIR/etc/os-release"
+    chmod 000 "$BATS_TEST_TMPDIR/etc/os-release"
+    
+    handle_permission_error() {
+        local file="$BATS_TEST_TMPDIR/etc/os-release"
+        if [[ ! -r "$file" ]]; then
+            echo "Error: Insufficient permissions to read $file"
+            echo "Try: Run with appropriate permissions or contact system administrator"
+            return 1
+        fi
+        return 0
+    }
+    
+    run handle_permission_error
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "Insufficient permissions" ]]
+    [[ "$output" =~ "Try: Run with appropriate permissions" ]]
+}
\ No newline at end of file