refactor(plugins): use cached background completion generation

plugins/invoke/invoke.plugin.zsh

@@ -1,5 +1,14 @@
-# Autocompletion for invoke.
+# Autocompletion for the Invoke CLI (invoke).
-#
+if (( ! $+commands[invoke] )); then
-if [ $commands[invoke] ]; then
+  return
-  source <(invoke --print-completion-script=zsh)
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `invoke`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_invoke" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _invoke
+  _comps[invoke]=_invoke
+fi
+
+invoke --print-completion-script=zsh >| "$ZSH_CACHE_DIR/completions/_invoke" &|

plugins/istioctl/istioctl.plugin.zsh

@@ -1,4 +1,14 @@
-if [ $commands[istioctl] ]; then
+# Autocompletion for the Istio CLI (istioctl).
-  source <(istioctl completion zsh)
+if (( ! $+commands[istioctl] )); then
-  compdef _istioctl istioctl
+  return
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `istioctl`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_istioctl" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _istioctl
+  _comps[istioctl]=_istioctl
+fi
+
+istioctl completion zsh >| "$ZSH_CACHE_DIR/completions/_istioctl" &|

plugins/kn/kn.plugin.zsh

@@ -1,8 +1,17 @@
-# Autocompletion for kn, the command line interface for knative
+# Autocompletion for kn, the command line interface for Knative.
 #
 # Author: https://github.com/btannous
 
-if [ $commands[kn] ]; then
+if (( ! $+commands[kn] )); then
-  source <(kn completion zsh)
+  return
-  compdef _kn kn
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `kn`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_kn" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _kn
+  _comps[kn]=_kn
+fi
+
+kn completion zsh >| "$ZSH_CACHE_DIR/completions/_kn" &|

plugins/kompose/kompose.plugin.zsh

@@ -1,3 +1,14 @@
-if [ $commands[kompose] ]; then
+# Autocompletion for the Kompose CLI (kompose).
-  source <(kompose completion zsh)
+if (( ! $+commands[kompose] )); then
+  return
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `kompose`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_kompose" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _kompose
+  _comps[kompose]=_kompose
+fi
+
+kompose completion zsh >| "$ZSH_CACHE_DIR/completions/_kompose" &|

plugins/kops/kops.plugin.zsh

@@ -1,3 +1,14 @@
-if [ $commands[kops] ]; then
+# Autocompletion for the Kubernetes Operations CLI (kops).
-  source <(kops completion zsh)
+if (( ! $+commands[kops] )); then
+  return
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `kops`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_kops" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _kops
+  _comps[kops]=_kops
+fi
+
+kops completion zsh >| "$ZSH_CACHE_DIR/completions/_kops" &|

plugins/oc/oc.plugin.zsh

@@ -2,7 +2,16 @@
 #
 # Author: https://github.com/kevinkirkup
 
-if [ $commands[oc] ]; then
+if (( ! $+commands[oc] )); then
-  source <(oc completion zsh)
+  return
-  compdef _oc oc
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `oc`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_oc" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _oc
+  _comps[oc]=_oc
+fi
+
+oc completion zsh >| "$ZSH_CACHE_DIR/completions/_oc" &|

plugins/operator-sdk/operator-sdk.plugin.zsh

@@ -1,4 +1,14 @@
-if [ $commands[operator-sdk] ]; then
+# Autocompletion for the Operator SDK CLI (operator-sdk).
-  source <(operator-sdk completion zsh)
+if (( ! $+commands[operator-sdk] )); then
-  compdef _operator-sdk operator-sdk
+  return
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `operator-sdk`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_operator-sdk" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _operator-sdk
+  _comps[operator-sdk]=_operator-sdk
+fi
+
+operator-sdk completion zsh >| "$ZSH_CACHE_DIR/completions/_operator-sdk" &|

plugins/please/please.plugin.zsh

@@ -1,7 +1,18 @@
-if (( $+commands[plz] )); then
+# Autocompletion for the Please build system CLI (plz).
-    source <(plz --completion_script)
+if (( ! $+commands[plz] )); then
+  return
 fi
 
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `plz`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_plz" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _plz
+  _comps[plz]=_plz
+fi
+
+plz --completion_script >| "$ZSH_CACHE_DIR/completions/_plz" &|
+
 alias pb='plz build'
 alias pt='plz test'
 alias pw='plz watch'

plugins/svcat/svcat.plugin.zsh

@@ -1,6 +1,14 @@
-# Autocompletion for svcat.
+# Autocompletion for the Service Catalog CLI (svcat).
-#
+if (( ! $+commands[svcat] )); then
-
+  return
-if [ $commands[svcat] ]; then
-  source <(svcat completion zsh)
 fi
+
+# If the completion file doesn't exist yet, we need to autoload it and
+# bind it to `svcat`. Otherwise, compinit will have already done that.
+if [[ ! -f "$ZSH_CACHE_DIR/completions/_svcat" ]]; then
+  typeset -g -A _comps
+  autoload -Uz _svcat
+  _comps[svcat]=_svcat
+fi
+
+svcat completion zsh >| "$ZSH_CACHE_DIR/completions/_svcat" &|