demo-core: Add prompt subcommand for lib/prompt

Author: mbland

libexec/demo-core.d/prompt

@@ -0,0 +1,37 @@
+#! /usr/bin/env bash
+#
+# Demonstration of `lib/prompt` capabilities
+#
+# Usage:
+#   {{go}} {{cmd}}
+#
+# Use this program to get a feel for the core `@go.prompt_for_input` and
+# `@go.prompt_for_yes_or_no` functions, and for examples of how to use them in
+# your own scripts.
+
+. "$_GO_USE_MODULES" 'prompt'
+
+_@go.prompt_demo() {
+  local name
+  local quest='To seek the grail!'
+
+  # No default value; returns error on no input.
+  if ! @go.prompt_for_input 'name' $'What is your name?\n' '' \
+    'Run away, Sir or Madam Not Appearing in this Film! Run away!'; then
+    return 1
+  fi
+  @go.printf 'Nice to meet you, %s!\n' "$name"
+
+  if @go.prompt_for_yes_or_no 'Do you have a quest?' 'yes'; then
+    # Default value applies if input is empty.
+    if ! @go.prompt_for_input 'quest' $'What is your quest?\n' "$quest"; then
+      return 1
+    fi
+  elif ! @go.prompt_for_yes_or_no "Might I suggest: $quest" 'yes'; then
+    @go.printf 'OK, no quest. Suit yourself!\n'
+    return 1
+  fi
+  @go.printf 'Your quest is: %s\n' "$quest"
+}
+
+_@go.prompt_demo "$@"

tests/demo-core/prompt.bats

@@ -0,0 +1,72 @@
+#! /usr/bin/env bats
+
+load ../environment
+
+setup() {
+  test_filter
+}
+
+teardown() {
+  @go.remove_test_go_rootdir
+}
+
+@test "$SUITE: use default quest option" {
+  run "$_GO_SCRIPT" demo-core prompt <<<$'Mike\n\n'
+  assert_success
+  split_bats_output_into_lines
+
+  local default_quest='Do you have a quest? [Y/n] '
+  default_quest+='What is your quest? [default: To seek the grail!]'
+
+  assert_lines_equal 'What is your name?' \
+    'Nice to meet you, Mike!' \
+    "${default_quest}" \
+    'Your quest is: To seek the grail!'
+}
+
+@test "$SUITE: return error if name not specified" {
+  run "$_GO_SCRIPT" demo-core prompt <<<''
+  assert_failure 'What is your name?' \
+    'Run away, Sir or Madam Not Appearing in this Film! Run away!'
+}
+
+@test "$SUITE: specify a different quest" {
+  run "$_GO_SCRIPT" demo-core prompt \
+    <<<$'Mike\nyes\nTo go back and face the peril!'
+  assert_success
+  split_bats_output_into_lines
+
+  local default_quest='Do you have a quest? [Y/n] '
+  default_quest+='What is your quest? [default: To seek the grail!]'
+
+  assert_lines_equal 'What is your name?' \
+    'Nice to meet you, Mike!' \
+    "${default_quest}" \
+    'Your quest is: To go back and face the peril!'
+}
+
+@test "$SUITE: decline a quest" {
+  run "$_GO_SCRIPT" demo-core prompt <<<$'Mike\nno\nno'
+  assert_failure
+  split_bats_output_into_lines
+
+  local default_quest='Do you have a quest? [Y/n] '
+  default_quest+='Might I suggest: To seek the grail! [Y/n]'
+
+  assert_lines_equal 'What is your name?' \
+    'Nice to meet you, Mike!' \
+    "${default_quest} OK, no quest. Suit yourself!"
+}
+
+@test "$SUITE: suggest a quest and accept it" {
+  run "$_GO_SCRIPT" demo-core prompt <<<$'Mike\nno\nyes'
+  assert_success
+  split_bats_output_into_lines
+
+  local default_quest='Do you have a quest? [Y/n] '
+  default_quest+='Might I suggest: To seek the grail! [Y/n]'
+
+  assert_lines_equal 'What is your name?' \
+    'Nice to meet you, Mike!' \
+    "${default_quest} Your quest is: To seek the grail!"
+}