feature (completion): add nestjs completion with conditions

completion/available/nest.completion.bash

@@ -0,0 +1,70 @@
+# shellcheck shell=bash
+cite "about-completion"
+about-completion "nestjs CLI completion"
+
+if _command_exists nest; then
+	function __nestjs_completion() {
+		local prev
+		local curr
+		local cmd
+		cmd=${COMP_WORDS[1]}
+		prev=$(_get_pword)
+		curr=$(_get_cword)
+
+		local HELP
+		HELP=(-h --help)
+
+		case $cmd in
+			n | new)
+				case $prev in
+					-p | --package-manager)
+						COMPREPLY=({p,}npm yarn)
+						;;
+					-l | --language)
+						COMPREPLY=({type,java}script)
+						;;
+					*)
+						COMPREPLY=("${HELP[@]}" --directory -d --dry-run -g --skip-git -s --skip-install -p --package-manager -l --language -c --collection)
+						;;
+				esac
+				;;
+			build | start)
+				COMPREPLY=("${HELP[@]}" -c --config -p --path -w --watch --watchAssets --webpack --webpackPath --tsc)
+				if [[ $cmd == "start" ]]; then
+					COMPREPLY=("${COMPREPLY[@]}" -e --exec --preserveWatchOutput)
+				fi
+				;;
+			i | info)
+				COMPREPLY=("${HELP[@]}")
+				;;
+			u | update)
+				case $prev in
+					-t | --tag)
+						COMPREPLY=(latest beta rc next)
+						;;
+					*)
+						COMPREPLY=("${HELP[@]}" -f --force -t --tag)
+						;;
+				esac
+				;;
+			add)
+				COMPREPLY=("${HELP[@]}" -d --dry-run -p --project)
+				;;
+			g | generate)
+				case $curr in
+					-*)
+						COMPREPLY=("${HELP[@]}" -d --dry-run -p --project --flat --{no,-}spec -c --collection)
+						;;
+					*)
+						COMPREPLY=(application class configuration controller decorator filter gateway guard interceptor interface middleware module pipe provider resolver service library sub-app resource)
+						;;
+				esac
+				;;
+			*)
+				COMPREPLY=("${HELP[@]}" -v --version new n build start info i update u add generate g)
+				;;
+		esac
+	}
+
+	complete -F __nestjs_completion -X "!&*" nest
+fi