Some attempts

.gitignore

@@ -24,3 +24,5 @@ pom.xml.asc
 **/*/*.ipynb_checkpoints
 concepts/functions-generating-functions/introduction_files/
 concepts/functions-generating-functions/*.html
+.problem-specifications/
+.cpcache/

bin/generate-tests

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# Synopsis:
+# Generate the tests for each exercise with a generator template.
+
+# Example: generate tests for all exercises with a generator template
+# bin/generate-tests
+
+# Example: generate tests for a single exercise with a generator template
+# bin/generate-tests two-fer
+
+set -eo pipefail
+
+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."
+}
+
+required_tool clj
+
+clj -X generator/run :exercise leap

exercises/practice/isogram/.meta/generator.template

@@ -0,0 +1,8 @@
+(ns isogram-test
+   (:require [clojure.test :refer [deftest testing is]]
+             isogram))
+{% for test_case in test_cases %}
+(deftest isogram_test_{{forloop.counter}}
+  (testing "{{test_case.path|join:" - "}}")
+    {% if test_case.expected %}(is (isogram/isogram? "{{test_case.input.phrase}}"))) {% else %}(is (not (isogram/isogram? "{{test_case.input.phrase}}")))) {% endif %}
+{% endfor %}

generators/deps.edn

@@ -0,0 +1,5 @@
+{:paths ["src"]
+ :deps {org.clojure/data.json {:mvn/version "2.5.1"}
+        selmer/selmer {:mvn/version "1.12.61"}
+        io.github.tonsky/toml-clj {:mvn/version "0.1.0"}
+        clj-jgit/clj-jgit {:mvn/version "1.1.0"}}}

generators/src/canonical_data.clj

@@ -0,0 +1,65 @@
+(ns canonical-data
+  (:require [clojure.data.json :as json]
+            [clojure.java.io :as io]
+            [toml-clj.core :as toml]
+            [clj-jgit.porcelain :refer [git-clone git-pull load-repo]]
+            [log]
+            [paths]))
+
+(def git-url "https://github.com/exercism/problem-specifications.git")
+
+(defn- pull-repo []
+  (-> paths/prob-specs-dir
+      (load-repo)
+      (git-pull)))
+
+(defn- clone-repo [] (git-clone git-url :branch "main" :dir paths/prob-specs-dir))
+
+(defn sync-repo []
+  (try
+    (pull-repo)
+    (catch java.io.FileNotFoundException  _ (clone-repo))))
+
+(defn- canonical-data [slug]
+  (let [file (paths/canonical-data-file slug)]
+    (if (.exists file)
+      (json/read (io/reader file) :key-fn keyword)
+      (log/error (str "No canonical-data.json found for exercise '" slug "'")))))
+
+(defn- excluded-uuids [slug]
+  (let [file (paths/tests-toml-file slug)]
+    (if (.exists file)
+      (->> file
+           (io/reader)
+           (toml/read)
+           (filter #(= false (get (last %) "include")))
+           (map first)
+           (set))
+      (log/error (str "No tests.toml data found for exercise '" slug "'")))))
+
+(defn- excluded? [slug]
+  (let [excluded (excluded-uuids slug)]
+    (fn [node] (contains? excluded (:uuid node)))))
+
+(defn- node->test-case [node path]
+  (-> node
+      (assoc :path path :error (get-in node [:expected :error]))
+      (dissoc :reimplements :comments :scenarios)))
+
+(defn- test-case-nodes
+  ([node] (test-case-nodes node []))
+  ([node path]
+   (let [description (:description node)
+         children (:cases node)
+         updated-path (if description (conj path description) path)]
+     (if children
+       (mapcat #(test-case-nodes % updated-path) children)
+       [(node->test-case node updated-path)]))))
+
+(defn test-cases [slug]
+  (->> slug
+       (canonical-data)
+       (test-case-nodes)
+       (remove (excluded? slug))
+       (into [])))
+

generators/src/generator.clj

@@ -0,0 +1,19 @@
+(ns generator
+  (:require [clojure.string :as str]
+            [canonical-data]
+            [templates]
+            [log]))
+
+(defn- slugs-to-generate [slug]
+  (let [slugs templates/exercises-with-template]
+    (if (str/blank? slug)
+      slugs
+      (if (contains? slugs slug)
+        [slug]
+        (log/error (str "No template found for exercise '" slug "'"))))))
+
+(defn- run [{:keys [exercise]}]
+  (canonical-data/sync-repo)
+  (doseq [slug (slugs-to-generate (str exercise))]
+    (log/normal (str "Generating tests for exercise '" slug "'"))
+    (templates/generate-tests-file slug (canonical-data/test-cases slug))))  

generators/src/log.clj

@@ -0,0 +1,8 @@
+(ns log)
+
+(defn normal [message]
+  (println message))
+
+(defn error [message]
+  (println message)
+  (System/exit 1))

generators/src/paths.clj

@@ -0,0 +1,14 @@
+(ns paths
+  (:require [clojure.java.io :as io]
+            [clojure.string :as str]))
+
+(def generators-dir (.getCanonicalPath (io/file ".")))
+(def root-dir (.getCanonicalPath (io/file generators-dir "..")))
+(def prob-specs-dir (io/file generators-dir ".problem-specifications"))
+(def exercises-dir (io/file root-dir "exercises" "practice"))
+(defn exercise-dir [slug] (io/file exercises-dir slug))
+(defn canonical-data-file [slug] (io/file prob-specs-dir "exercises" slug "canonical-data.json"))
+(defn tests-toml-file [slug] (io/file (exercise-dir slug) ".meta" "tests.toml"))
+(defn generator-template-file [slug] (io/file (exercise-dir slug) ".meta" "generator.template"))
+(defn tests-file-name [slug] (str (str/replace slug "-" "_") "_test.clj"))
+(defn tests-file [slug] (io/file (exercise-dir slug) "test" (tests-file-name slug)))

generators/src/templates.clj

@@ -0,0 +1,24 @@
+(ns templates
+  (:require [selmer.parser :as selmer]
+            [log]
+            [paths]))
+
+(def exercises-with-template
+  (->> paths/exercises-dir
+       (file-seq)
+       (filter #(.isFile %))
+       (filter #(= "generator.template" (.getName %)))
+       (map #(-> % (.getParentFile) (.getParentFile) (.getName)))
+       (set)))
+
+(defn- render-template [data template]
+  (selmer/render (slurp template) data))
+
+(defn- render [slug test-cases]
+  (let [data {:slug slug :test_cases test-cases}]
+    (render-template data (paths/generator-template-file slug))))
+
+(defn generate-tests-file [slug test-cases]
+  (->> test-cases
+       (render slug)
+       (spit (paths/tests-file slug))))