core, prompt: Move @go.select_option to lib/prompt

More user input functions will be added to `lib/prompt` in the next
commit.

Author: mbland

go-core.bash

@@ -229,43 +229,6 @@ declare _GO_INJECT_MODULE_PATH="$_GO_INJECT_MODULE_PATH"
   return "$result"
 }
 
-# Prompts the user to select one item from a list of options.
-#
-# This is a thin wrapper around the `select` builtin command for
-# straightforward, single-option user prompts. If you need to do anything more
-# complex, use the `select` builtin command directly.
-#
-# This will prompt the user for a single input, returned in the caller-declared
-# variable identified by `result_var`. If the user enters an invalid option,
-# this will notify the user and prompt again. If the user terminates input (via
-# EOF, i.e. Ctrl-D), `result_var` will remain unchanged and the function will
-# return nonzero.
-#
-# Globals:
-#   PS3  environment variable defining the selection prompt
-#
-# Arguments:
-#   result_var:  Name of the caller-declared variable used to store the option
-#   ...:         Strings representing options available for the user to select
-#
-# Returns:
-#   zero if `result_var` contains the user's selection, nonzero otherwise
-@go.select_option() {
-  local __go_selected_option
-  select __go_selected_option in "${@:2}"; do
-    case "$__go_selected_option" in
-    '')
-      @go.printf '"%s" is not a valid option.\n' "$REPLY" >&2
-      ;;
-    *)
-      printf -v "$1" -- '%s' "$__go_selected_option"
-      break
-      ;;
-    esac
-  done
-  [[ -n "$__go_selected_option" ]]
-}
-
 # Searches through plugin directories using a helper function
 #
 # The search will begin in `_GO_SCRIPTS_DIR/plugins`. As long as `search_func`

lib/prompt

@@ -0,0 +1,48 @@
+#! /usr/bin/env bash
+#
+# User input prompts
+#
+# Exports:
+#   @go.select_option
+#     Prompts the user to select one item from a list of options
+
+. "$_GO_USE_MODULES" 'validation'
+
+# Prompts the user to select one item from a list of options.
+#
+# This is a thin wrapper around the `select` builtin command for
+# straightforward, single-option user prompts. If you need to do anything more
+# complex, use the `select` builtin command directly.
+#
+# This will prompt the user for a single input, returned in the caller-declared
+# variable identified by `result_var`. If the user enters an invalid option,
+# this will notify the user and prompt again. If the user terminates input (via
+# EOF, i.e. Ctrl-D), `result_var` will remain unchanged and the function will
+# return nonzero.
+#
+# Globals:
+#   PS3  environment variable defining the selection prompt
+#
+# Arguments:
+#   result_var:  Name of the caller-declared variable used to store the option
+#   ...:         Strings representing options available for the user to select
+#
+# Returns:
+#   zero if `result_var` contains the user's selection, nonzero otherwise
+@go.select_option() {
+  @go.validate_identifier_or_die 'Result variable name' "$1"
+
+  local __go_selected_option
+  select __go_selected_option in "${@:2}"; do
+    case "$__go_selected_option" in
+    '')
+      @go.printf '"%s" is not a valid option.\n' "$REPLY" >&2
+      ;;
+    *)
+      printf -v "$1" -- '%s' "$__go_selected_option"
+      break
+      ;;
+    esac
+  done
+  [[ -n "$__go_selected_option" ]]
+}

libexec/demo-core.d/select-option

@@ -12,6 +12,8 @@
 # Use this program to get a feel for the core `@go.select_option` function, and
 # for an example of how to use it in your own scripts.
 
+. "$_GO_USE_MODULES" 'prompt'
+
 select_option_demo() {
   local options=("$@")
   local selected

tests/core/select-option.bats renamed to tests/prompt/select-option.bats

@@ -4,7 +4,8 @@ load ../environment
 
 setup() {
   test_filter
-  @go.create_test_go_script 'declare selection' \
+  @go.create_test_go_script '. "$_GO_USE_MODULES" "prompt"' \
+    'declare selection' \
     'if @go.select_option "selection" "$@"; then' \
     '  printf "\nSelection: \"%s\"\n" "$selection"' \
     'else' \