Update bin/generate_practice_exercise

bin/generate_practice_exercise

@@ -1,13 +1,35 @@
 #!/usr/bin/env bash
 
-# Exit if anything fails.
+# Synopsis:
+# Scaffold the files for a new practice exercise.
+# After creating the exercise, follow the instructions in the output.
+
+# Example:
+# bin/add-practice-exercise two-fer
+
+# Example with difficulty:
+# bin/add-practice-exercise -d 5 two-fer
+
+# Example with author and difficulty:
+# bin/add-practice-exercise -a foo -d 3 two-fer
+
 set -euo pipefail
+scriptname=$0
 
-# If argument not provided, print usage and exit
-if [ -z "$1" ]; then
-    echo "Usage: bin/generate_practice_exercise <exercise-slug>"
+help_and_exit() {
+    echo >&2 "Scaffold the files for a new practice exercise."
+    echo >&2 "Usage: ${scriptname} [-h] [-a author] [-d difficulty] <exercise-slug>"
+    echo >&2 "Where: author is the GitHub username of the exercise creator."
+    echo >&2 "Where: difficulty is between 1 (easiest) to 10 (hardest)."
     exit 1
-fi
+}
+
+die() { echo >&2 "$*"; exit 1; }
+
+require_files_template() {
+    jq -e --arg key "${1}" '.files[$key] | length > 0' config.json > /dev/null ||
+        die "The '.files.${1}' array in the 'config.json' file is empty. Please add at least one file. See https://exercism.org/docs/building/tracks/config-json#h-files for more information."
+}
 
 if ! [ -x "$(command -v jq)" ]; then
     echo "jq is required. Please install jq and make sure it is on the $PATH: https://stedolan.github.io/jq/download/" >&2
@@ -19,28 +41,62 @@ if ! [ -x "$(command -v emacs)" ]; then
     exit 1
 fi
 
-SLUG="$1"
-exercise_dir="exercises/practice/${SLUG}"
+require_files_template "solution"
+require_files_template "test"
+require_files_template "example"
 
-download() {
-    file="$1"
-    url="$2"
-    curl --silent --show-error --fail --retry 3 --max-time 3 \
-        --output "$file" "$url"
-}
+[[ -f ./bin/fetch-configlet ]] || die "Run this script from the repo's root directory."
+
+author=''
+difficulty=''
+while getopts :ha:d: opt; do
+    case $opt in
+        h) help_and_exit ;;
+        a) author=$OPTARG ;;
+        d) difficulty=$OPTARG ;;
+        ?) echo >&2 "Unknown option: -$OPTARG"; help_and_exit ;;
+    esac
+done
+shift "$((OPTIND - 1))"
+
+(( $# >= 1 )) || help_and_exit
+
+slug="${1}"
+
+if [[ -z "${author}" ]]; then
+    read -rp 'Your GitHub username: ' author
+fi
+
+if [[ -z "${difficulty}" ]]; then
+    read -rp "What's the difficulty for ${slug}? " difficulty
+fi
 
-# build configlet
 echo "Fetching latest version of configlet..."
 ./bin/fetch-configlet
 
-# Preparing config.json
 echo "Adding instructions and configuration files..."
-./bin/configlet create --practice-exercise "$SLUG"
+./bin/configlet create --practice-exercise "${slug}" --author "${author}" --difficulty "${difficulty}"
+
+filter='.exercises.practice = (.exercises.practice | sort_by(.difficulty, .slug))'
+jq "${filter}" config.json > config.sorted && mv config.sorted config.json
 
 pushd tools
-emacs -batch -l install-packages.el -l practice-exercise-generator.el --eval "(exercism/generate-practice-exercise \"$SLUG\")"
+emacs -batch -l install-packages.el -l practice-exercise-generator.el --eval "(exercism/generate-practice-exercise \"${slug}\")"
 popd
 
-echo "All stub files were created. After implementing the solution, tests and configuration, please run:"
-echo "    ./bin/configlet sync --update --tests --exercise ${SLUG}"
-echo "    ./bin/configlet fmt --update --yes --exercise ${SLUG}"
+exercise_dir="exercises/practice/${slug}"
+files=$(jq -r --arg dir "${exercise_dir}" '.files | to_entries | map({key: .key, value: (.value | map("'"'"'" + $dir + "/" + . + "'"'"'") | join(" and "))}) | from_entries' "${exercise_dir}/.meta/config.json")
+
+cat << NEXT_STEPS
+
+The test specifications have been copied into the test methods stubs by the generator.
+
+Your next steps are:
+- Implement the test suite in $(jq -r '.test' <<< "${files}")
+  - The tests are based on the canonical data at 'https://github.com/exercism/problem-specifications/blob/main/exercises/${slug}/canonical-data.json'
+  - Any test cases you don't implement, mark them in 'exercises/practice/${slug}/.meta/tests.toml' with "include = false"
+- Review the stub solution in $(jq -r '.solution' <<< "${files}")
+- Implement the example solution in $(jq -r '.example' <<< "${files}")
+- Verify the example solution passes the tests by running 'bin/test-examples'
+- Validate CI using 'bin/configlet lint' and 'bin/configlet fmt'
+NEXT_STEPS