Print API breakage warnings

api_diff.clj

#!/usr/bin/env bash
#_" -*- mode: clojure; -*-"
#_(
   "exec" "clojure" "-Sdeps" "{:deps {clj-kondo/clj-kondo {:mvn/version \"2020.12.12\"} org.clojure/tools.deps.alpha {:mvn/version \"0.9.857\"} org.slf4j/slf4j-nop {:mvn/version \"1.7.30\"} lambdaisland/deep-diff2 {:mvn/version \"2.0.108\"} juji/editscript {:mvn/version \"0.5.4\"}}}" "-M" "$0" "$@"
   )

;; Example usage:
;; api_diff.clj org.clojure/clojure "1.8.0" "1.10.1" > /tmp/diff.txt

(require '[clj-kondo.core :as clj-kondo])
(require '[clojure.edn :as edn])

(def lib (edn/read-string (first *command-line-args*)))
(def v1 (second *command-line-args*))
(def v2 (nth *command-line-args* 2))

(require '[clojure.tools.deps.alpha :as tda])
(require '[clojure.tools.deps.alpha.util.maven :as mvn])

(defn path [lib v]
  (let [deps `{:deps {~lib {:mvn/version ~v}} :mvn/repos ~mvn/standard-repos}]
    (-> (tda/resolve-deps deps {})
        (get lib)
        :paths first)))

(def path1 (path lib v1))
(def path2 (path lib v2))

(defn index-by
  [f coll]
  (persistent! (reduce #(assoc! %1 (f %2) %2) (transient {}) coll)))

(defn group [vars]
  (->> vars
       (map #(select-keys % [:ns :name :fixed-arities :varargs-min-arity]))
       (index-by (juxt :ns :name))))

(defn vars [lib]
  (-> (clj-kondo/run! {:lint [lib] :config {:output {:analysis true :format :edn}}})
      :analysis :var-definitions #_ clean))

(def vars-1 (vars path1))
(def vars-2 (vars path2))

#_(require '[lambdaisland.deep-diff2 :as ddiff])
#_(ddiff/pretty-print (ddiff/diff vars-1 vars-2))

;; (require '[editscript.core :as c])
;; (require '[editscript.edit :as e])
;; (def d (c/diff vars-1 vars-2))

;; (require '[clojure.pprint :refer [pprint]])
;; (pprint (e/get-edits d))

(defn var-symbol [[k v]]
  (str k "/" v))

(def compare-group-1 (group vars-1))
(def compare-group-2 (group vars-2))

(def lookup-1 (index-by (juxt :ns :name) vars-1))

(doseq [[k var-1] compare-group-1]
  (if-let [var-2 (get compare-group-2 k)]
    (let [fixed-arities-v1 (:fixed-arities var-1)
          fixed-arities-v2 (:fixed-arities var-2)
          varargs-min-arity (:varargs-min-arity var-2)]
      (doseq [arity fixed-arities-v1]
        (when-not (or (contains? fixed-arities-v2 arity)
                      (and varargs-min-arity (>= arity varargs-min-arity)))
          (let [{:keys [:filename :row :col :private]} (get lookup-1 k)]
            (println (str filename ":" row ":" col ":") (str (if private "warning" "error") ":")
                     "Arity" arity "of" (var-symbol k) "was removed.")))))
    (let [{:keys [:filename :row :col :private]} (get lookup-1 k)]
      (println (str filename ":" row ":" col ":") (str (if private "warning" "error") ":")
               (var-symbol k) "was removed."))))

clojure/pprint/cl_format.clj:168:1: warning: Arity 1 of clojure.pprint/format-simple-number was removed.
clojure/core_deftype.clj:572:1: warning: Arity 4 of clojure.core/emit-method-builder was removed.
clojure/core/reducers.clj:24:1: warning: clojure.core.reducers/compile-if was removed.

Also check out the bb version here: https://gist.github.com/borkdude/ba372c8cee311e31020b04063d88e1be