Update add exercise script to generic-track versions (#214)

This makes the track more consistent with more recent tracks and also allows passing in the difficulty

bin/add-exercise

@@ -1,81 +0,0 @@
-#!/usr/bin/env bash
-
-set -euo pipefail
-scriptname=$0
-
-help_and_exit() {
-    echo >&2 "Populates a new directory for a practice exercise."
-    echo >&2 "Usage: ${scriptname} [-h] [-a author] <exercise-slug>"
-    echo >&2 "Where: author is the github username of the exercise creator."
-    exit 1
-}
-
-die() { echo >&2 "$*"; exit 1; }
-
-required_tool() {
-    command -v "$1" >/dev/null 2>&1 ||
-        die "$1 is required but not installed. Please install it and make sure it's in your PATH."
-}
-
-(( $# >= 1 )) || help_and_exit
-
-required_tool jq
-required_tool curl
-
-[[ -f ./bin/fetch-configlet ]] || die "run this script from the repo's root directory."
-
-author=''
-while getopts :ha: opt; do
-    case $opt in
-        h) help_and_exit ;;
-        a) author=$OPTARG ;;
-        ?) echo >&2 "Unknown option: -$OPTARG"; help_and_exit ;;
-    esac
-done
-shift "$((OPTIND - 1))"
-
-slug="${1}"
-
-# Create entry for exercise in config.json and exercise files
-./bin/fetch-configlet
-./bin/configlet create --practice-exercise "${slug}"
-
-cp ./libs/exercism/test "exercises/practice/${slug}/libs/exercism/test"
-
-cat << END_TEST > "exercises/practice/${slug}/test.8th"
-"${slug}.8th" f:include
-needs exercism/test
-with: test
-N tests
-
-$(curl --silent "https://raw.githubusercontent.com/exercism/problem-specifications/main/exercises/${slug}/canonical-data.json")
-
-end-of-tests
-;with
-END_TEST
-
-if [[ -z $author ]]; then
-    echo
-    read -rp 'Your github username: ' author
-fi
-
-conf="exercises/practice/${slug}/.meta/config.json"
-jq  --arg author "${author}" \
-    '.authors = [$author]' "${conf}" > "${conf}.tmp" \
-&& mv "${conf}.tmp" "${conf}"
-
-echo
-find "exercises/practice/${slug}" -type f -ls
-
-cat << NEXT_STEPS
-
-Your next steps are:
-- Create the test suite in 'exercises/practice/${slug}/test.8th'
-  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"
-- Create the example solution in 'exercises/practice/${slug}/.meta/example.8th'
-- Verify the example solution by running 'bin/test-no-docker ${slug}'
-- Create the stub solution in 'exercises/practice/${slug}/${slug}.8th'
-- Update the 'difficulty' value for the exercise's entry in the 'config.json' file
-- Validate CI using 'bin/configlet lint' and 'bin/configlet fmt'
-NEXT_STEPS

bin/add-practice-exercise

@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+
+# 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
+
+help_and_exit() {
+    echo >&2 "Scaffold the files for a new practice exercise."
+    echo >&2 "Usage: ${scriptname} [-h] [-a author] [-d difficulty] <exercise-slug>"
+    echo >&2 "Where: author is the GitHub username of the exercise creator."
+    echo >&2 "Where: difficulty is between 1 (easiest) to 10 (hardest)."
+    exit 1
+}
+
+die() { echo >&2 "$*"; exit 1; }
+
+required_tool() {
+    command -v "${1}" >/dev/null 2>&1 ||
+        die "${1} is required but not installed. Please install it and make sure it's in your PATH."
+}
+
+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."
+}
+
+required_tool jq
+
+require_files_template "solution"
+require_files_template "test"
+require_files_template "example"
+
+[[ -f ./bin/fetch-configlet ]] || die "Run this script from the repo's root directory."
+
+author=''
+difficulty='1'
+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 "${author}" ]]; then
+    read -rp 'Your GitHub username: ' author
+fi
+
+./bin/fetch-configlet
+./bin/configlet create --practice-exercise "${slug}" --author "${author}" --difficulty "${difficulty}"
+
+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")
+
+cp ./libs/exercism/test "exercises/practice/${slug}/libs/exercism/test"
+
+cat << END_TEST > "exercises/practice/${slug}/test.8th"
+"${slug}.8th" f:include
+needs exercism/test
+with: test
+N tests
+
+$(curl --silent "https://raw.githubusercontent.com/exercism/problem-specifications/main/exercises/${slug}/canonical-data.json")
+
+end-of-tests
+;with
+END_TEST
+
+cat << NEXT_STEPS
+
+Your next steps are:
+- Create the test suite in $(jq -r '.test' <<< "${files}")
+  - The tests should be 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"
+- Create the example solution in $(jq -r '.example' <<< "${files}")
+- Verify the example solution passes the tests by running 'bin/verify-exercises ${slug}'
+- Create the stub solution in $(jq -r '.solution' <<< "${files}")
+- Update the 'difficulty' value for the exercise's entry in the 'config.json' file in the repo's root
+- Validate CI using 'bin/configlet lint' and 'bin/configlet fmt'
+NEXT_STEPS