Optimize boolean operations

[Chemaclass]

📚 Description

Performance optimization for boolean operations in the assertion guard system. This PR replaces string-based boolean comparisons with integer arithmetic, which is significantly faster in Bash.

🔖 Changes

1. Replace boolean strings with integers (src/state.sh)

Changed _ASSERTION_FAILED_IN_TEST from string "true"/"false" to integer 1/0:

# Before
_ASSERTION_FAILED_IN_TEST=false

# After  
_ASSERTION_FAILED_IN_TEST=0

Why this matters: Integer comparison using arithmetic evaluation (( var )) is faster than string comparison [[ "$var" == "true" ]] because:

• Arithmetic evaluation is a single operation
• No string parsing or comparison overhead
• Bash optimizes arithmetic expressions at a lower level

2. Inline the guard check in all assertion functions (src/assert.sh, src/bashunit.sh)

Replaced function calls with direct inline arithmetic checks:

# Before - function call overhead
function assert::guard() {
  if state::is_assertion_failed_in_test; then
    return 1
  fi
  return 0
}

function assert_true() {
  assert::guard || return 0
  # ...
}

# After - direct inline check
function assert_true() {
  (( _ASSERTION_FAILED_IN_TEST )) && return 0
  # ...
}

Why this matters:

• Eliminates function call overhead (subshell/scope creation)
• Removes nested function call (assert::guard → state::is_assertion_failed_in_test)
• Direct variable access is faster than function indirection
• The guard is called at the start of every assertion, so this is a hot path

3. Extract and reuse str::strip_ansi function (src/str.sh)

Created a dedicated function to strip ANSI escape codes and reused it across the codebase:

function str::strip_ansi() {
  local input="$1"
  echo -e "$input" | sed -E 's/\x1B\[[0-9;]*[mK]//g; s/[[:cntrl:]]//g'
}

This consolidates the duplicated ANSI stripping logic that was previously inline in assert_equals, assert_not_equals, and str::rpad, combining two separate operations (ANSI removal + control char removal) into a single sed command.

✅ To-do list

• I updated the CHANGELOG.md to reflect the new feature or fix
• I updated the documentation to reflect the changes