zsh: Use $+commands[] instead of command -v

.config/zsh/autoload/git/gstash

@@ -9,7 +9,7 @@
 emulate -L zsh -o extendedglob
 
 # Return if fzf is not available
-if ! command -v fzf &>/dev/null; then
+if (( ! $+commands[fzf] )); then
 	printf "command not found: fzf" >&2
 	return 1
 fi
@@ -56,9 +56,8 @@ read -r -d '' <<EOT
 	git show "${(j:%n:)format}" "$date" --color=always --patch-with-stat "\$out"
 EOT
 fzf_preview[patch]="$fzf_preview[construct] { $REPLY"
-if command -v diff-so-fancy &>/dev/null; then
+(( ! $+commands[diff-so-fancy] )) ||
 	fzf_preview[patch]+=" | diff-so-fancy --color=always"
-fi
 fzf_preview[patch]+=" }"
 
 read -r -d '' <<EOT
@@ -69,9 +68,9 @@ fzf_preview[stat]="$fzf_preview[construct] { $REPLY }"
 # Put the commit hash into the clipboard
 # (If no known clipboard tool is available, just print it)
 local fzf_copy_command="$fzf_preview[construct] echo -n \"\$out\""
-if [[ $OSTYPE =~ darwin ]] && command -v pbcopy &>/dev/null; then
+if [[ $OSTYPE =~ darwin ]] && (( $+commands[pbcopy] )); then
 	fzf_copy_command+=" | pbcopy"
-elif command -v xclip &>/dev/null; then
+elif (( $+commands[xclip] )); then
 	fzf_copy_command+=" | xclip -selection c"
 fi