Simplified option variables for greater flexibility.

plugins/history-substring-search/history-substring-search.plugin.zsh

@@ -2,11 +2,11 @@
 
 source "${0:r:r}.zsh"
 
-if test "$CASE_SENSITIVE" = true; then
+if check-bool "$CASE_SENSITIVE"; then
   unset HISTORY_SUBSTRING_SEARCH_GLOBBING_FLAGS
 fi
 
-if test "$DISABLE_COLOR" = true; then
+if ! check-bool "$COLOR"; then
   unset HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_FOUND
   unset HISTORY_SUBSTRING_SEARCH_HIGHLIGHT_NOT_FOUND
 fi

plugins/screen/screen.plugin.zsh

@@ -11,7 +11,7 @@ alias sn="screen -U -S"
 alias sr="screen -a -A -U -D -R"
 
 # Auto
-if (( $SHLVL == 1 )) && ! check-bool "$DISABLE_AUTO_SCREEN"; then
+if (( $SHLVL == 1 )) && check-bool "$AUTO_SCREEN"; then
   (( SHLVL += 1 )) && export SHLVL
   session="$(screen -list 2> /dev/null | sed '1d;$d' | awk '{print $1}' | head -1)"
   if [[ -n "$session" ]]; then

plugins/ssh-agent/ssh-agent.plugin.zsh

@@ -40,7 +40,7 @@ function _ssh-agent-start() {
 
 # Test if agent-forwarding is enabled.
 zstyle -b :omz:plugins:ssh-agent agent-forwarding _ssh_agent_forwarding
-if [[ "${_ssh_agent_forwarding}" == "yes" && -n "$SSH_AUTH_SOCK" ]]; then
+if check-bool "${_ssh_agent_forwarding}" && [[ -n "$SSH_AUTH_SOCK" ]]; then
   # Add a nifty symlink for screen/tmux if agent forwarding.
   [[ -L "$SSH_AUTH_SOCK" ]] || ln -sf "$SSH_AUTH_SOCK" /tmp/ssh-agent-$USER-screen
 elif [ -f "${_ssh_agent_env}" ]; then

plugins/tmux/tmux.plugin.zsh

@@ -10,7 +10,7 @@ alias ta="tmux attach-session"
 alias tl="tmux list-sessions"
 
 # Auto
-if (( $SHLVL == 1 )) && ! check-bool "$DISABLE_AUTO_TMUX"; then
+if (( $SHLVL == 1 )) && check-bool "$AUTO_TMUX"; then
   (( SHLVL += 1 )) && export SHLVL
   session="$(tmux list-sessions 2> /dev/null | cut -d':' -f1 | head -1)"
   if [[ -n "$session" ]]; then