Don't allow unset variables in new Bash files

lib/commands/command-shim-versions.bash

@@ -2,7 +2,7 @@
 set -o nounset
 
 shim_versions_command() {
-  local shim_name=${1:-}
+  local shim_name="${1:-}"
   shim_plugin_versions "$shim_name"
 }
 

lib/commands/command-uninstall.bash

@@ -5,10 +5,10 @@ set -o nounset
 . "$(dirname "$ASDF_CMD_FILE")/reshim.bash"
 
 uninstall_command() {
-  local plugin_name=${1:-}
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
   local plugin_path
-  plugin_path=$(get_plugin_path "$plugin_name")
+  plugin_path="$(get_plugin_path "$plugin_name")"
 
   check_if_plugin_exists "$plugin_name"
 
@@ -22,7 +22,7 @@ uninstall_command() {
   fi
 
   local install_path
-  install_path=$(get_install_path "$plugin_name" "$install_type" "$version")
+  install_path="$(get_install_path "$plugin_name" "$install_type" "$version")"
 
   if [ ! -d "$install_path" ]; then
     display_error "No such version"
@@ -47,8 +47,8 @@ uninstall_command() {
 }
 
 remove_shims_for_version() {
-  local plugin_name=${1:-}
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
   for shim_path in $(plugin_shims "$plugin_name" "$full_version"); do
     remove_shim_for_version "$plugin_name" "$full_version" "$shim_path"
   done

lib/commands/command-update.bash

@@ -2,7 +2,7 @@
 set -o nounset
 
 update_command() {
-  local update_to_head=${1:-}
+  local update_to_head="${1:-}"
 
   (
     cd "$(asdf_dir)" || exit 1
@@ -17,7 +17,7 @@ update_command() {
 }
 
 do_update() {
-  local update_to_head=${1:-}
+  local update_to_head="${1:-}"
 
   if [ "$update_to_head" = "--head" ]; then
     # Update to latest on the master branch

lib/commands/command-where.bash

@@ -2,8 +2,8 @@
 set -o nounset
 
 where_command() {
-  local plugin_name=${1:-}
-  local full_version=${2:-}
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
   check_if_plugin_exists "$plugin_name"
 
   local version

lib/commands/command-which.bash

@@ -1,4 +1,5 @@
 # -*- sh -*-
+
 set -o nounset
 
 which_command() {

lib/commands/reshim.bash

@@ -27,8 +27,8 @@ remove_shim_for_version() {
 }
 
 reshim_command() {
-  local plugin_name=$1
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
 
   if [ -z "$plugin_name" ]; then
     local plugins_path
@@ -76,9 +76,9 @@ ensure_shims_dir() {
 }
 
 write_shim_script() {
-  local plugin_name=$1
-  local version=$2
-  local executable_path=$3
+  local plugin_name="${1:-}"
+  local version="${2:-}"
+  local executable_path="${3:-}"
 
   if ! is_executable "$executable_path"; then
     return 0
@@ -107,8 +107,8 @@ EOF
 }
 
 generate_shim_for_executable() {
-  local plugin_name=$1
-  local executable=$2
+  local plugin_name="${1:-}"
+  local executable="${2:-}"
 
   check_if_plugin_exists "$plugin_name"
 
@@ -124,8 +124,8 @@ generate_shim_for_executable() {
 }
 
 generate_shims_for_version() {
-  local plugin_name=$1
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
   local all_executable_paths
   IFS=$'\n' read -rd '' -a all_executable_paths <<<"$(plugin_executables "$plugin_name" "$full_version")"
   for executable_path in "${all_executable_paths[@]}"; do
@@ -134,8 +134,8 @@ generate_shims_for_version() {
 }
 
 remove_obsolete_shims() {
-  local plugin_name=$1
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
 
   local shims
   shims=$(plugin_shims "$plugin_name" "$full_version" | xargs -IX basename X | sort)
@@ -148,7 +148,7 @@ remove_obsolete_shims() {
   local formatted_exec_names
 
   local temp_dir
-  temp_dir=${TMPDIR:-/tmp}
+  temp_dir="${TMPDIR:-/tmp}"
 
   # comm only takes to files, so we write this data to temp files so we can
   # pass it to comm.

lib/functions/installs.bash

@@ -1,18 +1,18 @@
 handle_failure() {
-  local install_path="$1"
+  local install_path="${1:-}"
   rm -rf "$install_path"
   exit 1
 }
 
 handle_cancel() {
-  local install_path="$1"
+  local install_path="${1:-}"
   printf "\\nreceived sigint, cleaning up"
   handle_failure "$install_path"
 }
 
 install_command() {
-  local plugin_name=$1
-  local full_version=$2
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
   local extra_args="${*:3}"
 
   if [ "$plugin_name" = "" ] && [ "$full_version" = "" ]; then
@@ -37,7 +37,7 @@ get_concurrency() {
 }
 
 install_one_local_tool() {
-  local plugin_name=$1
+  local plugin_name="${1:-}"
   local search_path
   search_path=$(pwd)
 
@@ -131,9 +131,9 @@ install_local_tool_versions() {
 }
 
 install_tool_version() {
-  local plugin_name=$1
-  local full_version=$2
-  local flags=$3
+  local plugin_name="${1:-}"
+  local full_version="${2:-}"
+  local flags="${3:-}"
   local keep_download
   local plugin_path
 

lib/functions/plugins.bash

@@ -6,7 +6,7 @@ plugin_list_command() {
   local show_ref
 
   while [ -n "$*" ]; do
-    case "$1" in
+    case "${1:-}" in
     "--urls")
       show_repo=true
       shift
@@ -109,8 +109,8 @@ plugin_update_command() {
     exit 1
   fi
 
-  local plugin_name="$1"
-  local gitref="${2}"
+  local plugin_name="${1:-}"
+  local gitref="${2:-}"
   local plugins=
 
   if [ "$plugin_name" = "--all" ]; then
@@ -130,10 +130,10 @@ plugin_update_command() {
 }
 
 update_plugin() {
-  local plugin_name=$1
-  local plugin_path=$2
-  plugin_remote_default_branch=$(git --git-dir "$plugin_path/.git" --work-tree "$plugin_path" ls-remote --symref origin HEAD | awk '{ sub(/refs\/heads\//, ""); print $2; exit }')
-  local gitref=${3:-${plugin_remote_default_branch}}
+  local plugin_name="${1:-}"
+  local plugin_path="${2:-}"
+  plugin_remote_default_branch="$(git --git-dir "$plugin_path/.git" --work-tree "$plugin_path" ls-remote --symref origin HEAD | awk '{ sub(/refs\/heads\//, ""); print $2; exit }')"
+  local gitref="${3:-${plugin_remote_default_branch}}"
   logfile=$(mktemp)
 
   local common_git_options=(--git-dir "$plugin_path/.git" --work-tree "$plugin_path")

lib/functions/versions.bash

@@ -1,6 +1,6 @@
 version_command() {
-  local cmd=$1
-  local plugin_name=$2
+  local cmd="${1:-}"
+  local plugin_name="${2:-}"
 
   if [ "$#" -lt "3" ]; then
     if [ "$cmd" = "global" ]; then
@@ -65,17 +65,17 @@ version_command() {
 }
 
 list_all_command() {
-  local plugin_name=$1
-  local query=$2
+  local plugin_name="${1:-}"
+  local query="${2:-}"
   local plugin_path
   local std_out_file
   local std_err_file
   local output
-  plugin_path=$(get_plugin_path "$plugin_name")
+  plugin_path="$(get_plugin_path "$plugin_name")"
   check_if_plugin_exists "$plugin_name"
 
   local temp_dir
-  temp_dir=${TMPDIR:-/tmp}
+  temp_dir="${TMPDIR:-/tmp}"
 
   # Capture return code to allow error handling
   std_out_file="$(mktemp "$temp_dir/asdf-command-list-all-${plugin_name}.stdout.XXXXXX")"
@@ -117,8 +117,8 @@ list_all_command() {
 latest_command() {
   DEFAULT_QUERY="[0-9]"
 
-  local plugin_name=$1
-  local query=$2
+  local plugin_name="${1:-}"
+  local query="${2:-}"
   local plugin_path
 
   if [ "$plugin_name" == "--all" ]; then