Abort with usage help on wrong number of CLI arguments

- rbenv-install accepts 0 or 1 argument
- rbenv-uninstall accepts 1 argument
- ruby-build accepts 2 arguments

bin/rbenv-install

@@ -111,6 +111,8 @@ DEFINITION="${ARGUMENTS[0]}"
 [ -n "$DEFINITION" ] || DEFINITION="$(rbenv-local 2>/dev/null || true)"
 [ -n "$DEFINITION" ] || usage 1
 
+# Fail if number of arguments is greater than 1
+[ "${#ARGUMENTS[@]}" -le 1 ] || usage 1
 
 # Define `before_install` and `after_install` functions that allow
 # plugin hooks to register a string of code for execution before or

bin/rbenv-uninstall

@@ -17,6 +17,12 @@ if [ "$1" = "--complete" ]; then
   exec rbenv versions --bare
 fi
 
+usage() {
+  # We can remove the sed fallback once rbenv 0.4.0 is widely available.
+  rbenv-help uninstall 2>/dev/null || sed -ne '/^#/!q;s/.//;s/.//;1,4d;p' < "$0"
+  [ -z "$1" ] || exit "$1"
+}
+
 if [ -z "$RBENV_ROOT" ]; then
   RBENV_ROOT="${HOME}/.rbenv"
 fi
@@ -38,6 +44,9 @@ case "$DEFINITION" in
   ;;
 esac
 
+# Fail if number of arguments is not equal 1
+[ "$#" -eq 1 ] || usage 1
+
 declare -a before_hooks after_hooks
 
 before_uninstall() {

bin/ruby-build

@@ -1046,6 +1046,9 @@ elif [ "${PREFIX_PATH#/}" = "$PREFIX_PATH" ]; then
   PREFIX_PATH="${PWD}/${PREFIX_PATH}"
 fi
 
+# Fail if number of arguments is not equal to 2
+[ "${#ARGUMENTS[@]}" -eq 2 ] || usage
+
 if [ -z "$TMPDIR" ]; then
   TMP="/tmp"
 else

test/arguments.bats

+#!/usr/bin/env bats
+
+load test_helper
+
+@test "not enought arguments for ruby-build" {
+  # use empty inline definition so nothing gets built anyway
+  local definition="${TMP}/build-definition"
+  echo '' > "$definition"
+
+  run ruby-build "$definition"
+  assert_failure
+  assert_output_contains 'usage: ruby-build'
+}
+
+@test "extra arguments for ruby-build" {
+  # use empty inline definition so nothing gets built anyway
+  local definition="${TMP}/build-definition"
+  echo '' > "$definition"
+
+  run ruby-build "$definition" 2.1.2 "${TMP}/install"
+  assert_failure
+  assert_output_contains 'usage: ruby-build'
+}
+
+@test "extra arguments for rbenv-install" {
+  stub ruby-build "--lib : $BATS_TEST_DIRNAME/../bin/ruby-build --lib"
+  stub rbenv-hooks
+  stub rbenv-rehash
+
+  run rbenv-install 2.1.1 2.1.2
+  assert_failure
+  assert_output_contains 'Usage: rbenv install'
+
+  unstub ruby-build
+  unstub rbenv-hooks
+  unstub rbenv-rehash
+}
+
+@test "not enough arguments rbenv-uninstall" {
+  run rbenv-uninstall
+  assert_failure
+  assert_output_contains 'Usage: rbenv uninstall'
+}
+
+@test "extra arguments for rbenv-uninstall" {
+  stub rbenv-hooks
+
+  run rbenv-uninstall 2.1.1 2.1.2
+  assert_failure
+  assert_output_contains 'Usage: rbenv uninstall'
+
+  unstub rbenv-hooks
+}