Proof-of-concept external completions

completions/rbenv.bash

@@ -1,29 +1,14 @@
-_rbenv_commands() {
-  COMPREPLY=()
-  local cur="${COMP_WORDS[COMP_CWORD]}"
-  COMPREPLY=( $( compgen -W "$(rbenv commands)" -- $cur ) )
-}
-
-_rbenv_versions() {
-  COMPREPLY=()
-  local cur="${COMP_WORDS[COMP_CWORD]}"
-  local versions="$(echo system; rbenv versions --bare)"
-  COMPREPLY=( $( compgen -W "$versions" -- $cur ) )
-}
-
 _rbenv() {
   COMPREPLY=()
-  local cur="${COMP_WORDS[COMP_CWORD]}"
-  local prev="${COMP_WORDS[COMP_CWORD-1]}"
-
-  case "$prev" in
-  set-* | global | local | shell | prefix )
-    _rbenv_versions
-    ;;
-  * )
-    _rbenv_commands
-    ;;
-  esac
+  local word="${COMP_WORDS[COMP_CWORD]}"
+
+  if [ "$COMP_CWORD" -eq 1 ]; then
+    COMPREPLY=( $(compgen -W "$(rbenv commands)" -- "$word") )
+  else
+    local command="${COMP_WORDS[1]}"
+    local completions="$(rbenv completions "$command")"
+    COMPREPLY=( $(compgen -W "$completions" -- "$word") )
+  fi
 }
 
 complete -F _rbenv rbenv

libexec/rbenv-completions

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+set -e
+[ -n "$RBENV_DEBUG" ] && set -x
+
+COMMAND="$1"
+if [ -z "$COMMAND" ]; then
+  echo "usage: rbenv completions COMMAND [arg1 arg2...]" >&2
+  exit 1
+fi
+
+COMMAND_PATH="$(command -v "rbenv-$COMMAND")"
+if grep -i "^# provide rbenv completions" "$COMMAND_PATH" >/dev/null; then
+  shift
+  exec "$COMMAND_PATH" --complete "$@"
+fi

libexec/rbenv-local

@@ -2,6 +2,13 @@
 set -e
 [ -n "$RBENV_DEBUG" ] && set -x
 
+# Provide rbenv completions
+if [ "$1" = "--complete" ]; then
+  shift
+  echo system
+  exec rbenv-versions --bare
+fi
+
 RBENV_VERSION="$1"
 RBENV_VERSION_FILE=".rbenv-version"