nix/maintainers/add-release-note

#!/usr/bin/env bash

set -euo pipefail

log() {
  echo >&2 "$@"
}
die() {
  printf >&2 "add-release-note: \033[31;1merror:\033[0m"
  echo >&2 "" "$@"
  exit 1
}
warn() {
  printf >&2 "add-release-note: \033[33;1mwarning:\033[0m"
  echo >&2 "" "$@"
}

dir="$(dirname "${BASH_SOURCE[0]}")"/..
cd $dir
test -e .git || die "$(pwd) is not a git repo"
test -e flake.nix || die "$(pwd) is not a flake, let alone the NixOS/nix flake"

prompt_required() {
  local prompt="$1"
  local value
  while read -r -p "$prompt (required) > " value; do
    if [[ -z "$value" ]]; then
      log "please enter a value"
    else
      echo $value
      break
    fi
  done
}

prompt_default() {
  local prompt="$1"
  local default="$2"
  local value
  read -r -p "$prompt [default: $default] > " value
  if [[ -z "$value" ]]; then
    value="$default"
  fi
  echo $value
}

prompt_optional() {
  prompt_default "$1 (optional)" ""
}

prompt_bool() {
  local prompt="$1"
  local value
  while read -r -p "$prompt (y/n) > " value; do
    case "$value" in
      y|Y|yes|Yes|YES)
        echo true
        break
        ;;
      n|N|no|No|NO)
        echo false
        break
        ;;
      *)
        log "please answer y or n"
        ;;
    esac
  done
}

title="$(prompt_required "short title" version)"
log
log "Hint: https://github.com/NixOS/nix/issues"
issues="$(prompt_optional "issue number(s) in #1234 format, space separated")"
log
log "Hint: https://github.com/NixOS/nix/pulls/@me"
prs="$(prompt_optional "pr number(s) in #1234 format, space separated")"
log
log "Significant changes are moved to their own section at the start of the release notes."
is_significant="$(prompt_bool "is this a significant change?")"

if $is_significant; then
  log
  log "Great release notes describe what changed for users. You can use markdown and expand on this in your editor later."
  description="$(prompt_required "longer description")"
else
  log
  log "Great release notes describe what changed for users. You can use markdown and expand on this in your editor later."
  description="$(prompt_optional "longer description")"

  if [[ -z "$description" ]]; then
    log
    log ""
    later="$(prompt_bool "Write a description later in your editor?")"
    if $later; then
      description="<!-- remove this markdown comment and write a description to inform users -->"
    fi
  fi
fi

if [[ -n "$issues" ]]; then
  name="issue-$(sed -e 's/[^0-9]/-/g' -e 's/--*/-/g' -e 's/^-//g' -e 's/-$//g' <<< "$issues")"
elif [[ -n "$prs" ]]; then
  name="pr-$(sed -e 's/[^0-9]/-/g' -e 's/--*/-/g' -e 's/^-//g' -e 's/-$//g' <<< "$prs")"
else
  name="$(sed -e 's/[^a-zA-Z0-9]/-/g' -e 's/--*/-/g' -e 's/^-//g' -e 's/-$//g' <<< "$title" | tr '[:upper:]' '[:lower:]')"
fi

file="doc/manual/rl-next/$name.md"

if [[ -e "$file" ]]; then
  warn "file already exists: $file"
  log "You may paste the following into an appropriate file, and edit it:"
  log
  file=/dev/stdout
fi

(
  echo "synopsis: $title"
  if [[ -n "$issues" ]]; then
    echo "issues: $issues"
  fi
  if $is_significant; then
    echo "significance: significant"
  fi
  if [[ -n "$prs" ]]; then
    echo "prs: $prs"
  fi
  if [[ -n "$description" ]]; then
    echo "description: {"
    echo
    echo "$description"
    echo
    echo "}"
  fi
) >"$file"

log
log "Release note written to $file"

if [[ /dev/stdout != "$file" ]]; then
  edit="$(prompt_bool "Edit in $EDITOR?")"
  if $edit; then
    "$EDITOR" "$file"
  fi

  git_add="$(prompt_bool "Add to git?")"
  if $git_add; then
    git add "$file"
  fi
else
  die "file not written"
fi