fix(compat): convert all literal regex patterns to variables

Store all regex patterns in variables before use to ensure Bash 3.0
compatibility. In Bash < 3.2, regex matching with literal patterns
doesn't work properly.

Fixed patterns in:
- src/doc.sh: code fence pattern
- src/main.sh: digit validation pattern
- src/helpers.sh: test name patterns and variable name validation
- src/runner.sh: metacharacter detection patterns
- src/clock.sh: digit validation pattern
- src/assert.sh: eval and alias detection patterns

All patterns now follow the safe approach:
local _pattern='...'
[[ $var =~ $_pattern ]]

Author: Chemaclass

src/assert.sh

@@ -83,9 +83,12 @@ function assert_false() {
 function bashunit::run_command_or_eval() {
   local cmd="$1"
 
-  if [[ "$cmd" =~ ^eval ]]; then
+  # Patterns stored in variable for Bash 3.0 compatibility
+  local _eval_pattern='^eval'
+  local _alias_pattern='^alias'
+  if [[ "$cmd" =~ $_eval_pattern ]]; then
     eval "${cmd#eval }" &>/dev/null
-  elif [[ "$(command -v "$cmd")" =~ ^alias ]]; then
+  elif [[ "$(command -v "$cmd")" =~ $_alias_pattern ]]; then
     eval "$cmd" &>/dev/null
   else
     "$cmd" &>/dev/null

src/clock.sh

@@ -45,7 +45,9 @@ function bashunit::clock::_choose_impl() {
   if ! bashunit::check_os::is_macos && ! bashunit::check_os::is_alpine; then
     local result
     result=$(date +%s%N 2>/dev/null)
-    if [[ "$result" != *N && "$result" =~ ^[0-9]+$ ]]; then
+    # Pattern stored in variable for Bash 3.0 compatibility
+    local _digit_pattern='^[0-9]+$'
+    if [[ "$result" != *N && "$result" =~ $_digit_pattern ]]; then
       _BASHUNIT_CLOCK_NOW_IMPL="date"
       return 0
     fi

src/doc.sh

@@ -32,7 +32,9 @@ function bashunit::doc::print_asserts() {
     fi
 
     if ((should_print)); then
-      if [[ "$line" =~ ^\`\`\` ]]; then
+      # Pattern stored in variable for Bash 3.0 compatibility
+      local _code_fence_pattern='^\`\`\`'
+      if [[ "$line" =~ $_code_fence_pattern ]]; then
         echo "--------------"
         echo "$docstring"
         should_print=0

src/helpers.sh

@@ -31,7 +31,9 @@ function bashunit::helper::find_test_function_name() {
   for ((i = 0; i < ${#FUNCNAME[@]}; i++)); do
     local fn="${FUNCNAME[$i]}"
     # Check if function starts with "test_" or "test" followed by uppercase
-    if [[ "$fn" == test_* ]] || [[ "$fn" =~ ^test[A-Z] ]]; then
+    # Pattern stored in variable for Bash 3.0 compatibility
+    local _test_camel_pattern='^test[A-Z]'
+    if [[ "$fn" == test_* ]] || [[ "$fn" =~ $_test_camel_pattern ]]; then
       echo "$fn"
       return
     fi
@@ -270,7 +272,9 @@ function bashunit::helper::normalize_variable_name() {
 
   normalized_string="${input_string//[^a-zA-Z0-9_]/_}"
 
-  if [[ ! $normalized_string =~ ^[a-zA-Z_] ]]; then
+  # Pattern stored in variable for Bash 3.0 compatibility
+  local _valid_start_pattern='^[a-zA-Z_]'
+  if [[ ! $normalized_string =~ $_valid_start_pattern ]]; then
     normalized_string="_$normalized_string"
   fi
 

src/main.sh

@@ -694,7 +694,9 @@ function bashunit::main::handle_assert_exit_code() {
     last_line=$(echo "$output" | tail -n 1)
     if echo "$last_line" | grep -q 'inner_exit_code:[0-9]*'; then
       inner_exit_code=$(echo "$last_line" | grep -o 'inner_exit_code:[0-9]*' | cut -d':' -f2)
-      if ! [[ $inner_exit_code =~ ^[0-9]+$ ]]; then
+      # Pattern stored in variable for Bash 3.0 compatibility
+      local _digit_pattern='^[0-9]+$'
+      if ! [[ $inner_exit_code =~ $_digit_pattern ]]; then
         inner_exit_code=1
       fi
       output=$(echo "$output" | sed '$d')

src/runner.sh

@@ -215,8 +215,11 @@ function bashunit::runner::parse_data_provider_args() {
   local args_count=0
 
   # Check for shell metacharacters that would break eval or cause globbing
+  # Patterns stored in variable for Bash 3.0 compatibility
+  local _metachar_mid_pattern='[^\\][\|\&\;\*]'
+  local _metachar_start_pattern='^[\|\&\;\*]'
   local has_metachar=false
-  if [[ "$input" =~ [^\\][\|\&\;\*] ]] || [[ "$input" =~ ^[\|\&\;\*] ]]; then
+  if [[ "$input" =~ $_metachar_mid_pattern ]] || [[ "$input" =~ $_metachar_start_pattern ]]; then
     has_metachar=true
   fi