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jeroenvandijk/bb_reitit_demo_openapi.clj

Created October 30, 2025 19:52
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bb_reitit_demo_openapi.clj
;; Follow up of https://gist.github.com/jeroenvandijk/cb5f3411943c24dc68b225f34a3e474b
;;
;; Now trying to use reitit.openapi still some work in muuntaja.format.json or maybe the json part can be done differently
;;
;; Run this script with `bb bb_reitit_demo_openapi.clj` and visit http://localhost:3000/openapi.json
(require '[babashka.deps :as deps])
(deps/add-deps '{:deps {metosin/reitit {:mvn/version "0.9.2"}}})
;; --- START Reitit monkey patch
(ns reitit.trie
(:refer-clojure :exclude [compile])
(:require [clojure.string :as str]
[reitit.exception :as ex])
#?(:clj (:import (java.net URLDecoder)
;; Babashka cannot find the reitit.Trie class
#_[reitit Trie Trie$Match Trie$Matcher])))
(defn ^:no-doc into-set [x]
(cond
(or (set? x) (sequential? x)) (set x)
(nil? x) #{}
:else (conj #{} x)))
(defrecord Wild [value])
(defrecord CatchAll [value])
(defrecord Match [params data])
(defrecord Node [children wilds catch-all params data])
(defn wild? [x] (instance? Wild x))
(defn catch-all? [x] (instance? CatchAll x))
(defprotocol Matcher
(match [this i max path])
(view [this])
(depth ^long [this])
(length [this]))
(defprotocol TrieCompiler
(data-matcher [this params data])
(static-matcher [this path matcher])
(wild-matcher [this key end matcher])
(catch-all-matcher [this key params data])
(linear-matcher [this matchers ordered?])
(-pretty [this matcher])
(-path-matcher [this matcher]))
(defn- assoc-param [match k v]
(let [params (:params match)]
(assoc match :params (assoc params k v))))
;; https://stackoverflow.com/questions/8033655/find-longest-common-prefix
(defn- common-prefix [s1 s2]
(let [max (min (count s1) (count s2))]
(loop [i 0]
(cond
;; full match
(> i max)
(subs s1 0 max)
;; partial match
(not= (get s1 i) (get s2 i))
(if-not (zero? i) (subs s1 0 i))
;; recur
:else (recur (inc i))))))
(defn- -keyword [s]
(if-let [^long i (str/index-of s "/")]
(keyword (subs s 0 i) (subs s (inc i)))
(keyword s)))
(defn split-path [s {:keys [syntax] :or {syntax #{:bracket :colon}}}]
(let [bracket? (-> syntax (into-set) :bracket)
colon? (-> syntax (into-set) :colon)
-static (fn [from to] (if-not (= from to) [(subs s from to)]))
-wild (fn [^long from to] [(->Wild (-keyword (subs s (inc from) to)))])
-catch-all (fn [^long from to] [(->CatchAll (keyword (subs s (inc from) to)))])]
(loop [ss nil, from 0, to 0]
(if (= to (count s))
(concat ss (-static from to))
(let [c (get s to)]
(cond
(and bracket? (= \{ c))
(let [^long to' (or (str/index-of s "}" to) (ex/fail! ::unclosed-brackets {:path s}))]
(if (= \* (get s (inc to)))
(recur (concat ss (-static from to) (-catch-all (inc to) to')) (long (inc to')) (long (inc to')))
(recur (concat ss (-static from to) (-wild to to')) (long (inc to')) (long (inc to')))))
(and colon? (= \: c))
(let [^long to' (or (str/index-of s "/" to) (count s))]
(if (= 1 (- to' to))
(recur ss from (inc to))
(recur (concat ss (-static from to) (-wild to to')) (long to') (long to'))))
(and colon? (= \* c))
(let [to' (count s)]
(recur (concat ss (-static from to) (-catch-all to to')) (long to') (long to')))
:else
(recur ss from (inc to))))))))
(defn join-path [xs]
(reduce
(fn [s x]
(str s (cond
(string? x) x
(instance? Wild x) (str "{" (-> x :value str (subs 1)) "}")
(instance? CatchAll x) (str "{*" (-> x :value str (subs 1)) "}"))))
"" xs))
(defn normalize [s opts]
(-> s (split-path opts) (join-path)))
;;
;; Conflict Resolution
;;
(defn- -slice-start [[p1 :as p1s] [p2 :as p2s]]
(let [-split (fn [p]
(if-let [i (and p (str/index-of p "/"))]
[(subs p 0 i) (subs p i)]
[p]))
-slash (fn [cp p]
(cond
(not (string? cp)) [cp]
(and (string? cp) (not= (count cp) (count p))) [(subs p (count cp))]
(and (string? p) (not cp)) (-split p)))
-postcut (fn [[p :as pps]]
(let [^long i (and p (str/index-of p "/"))]
(if (and i (pos? i))
(concat [(subs p 0 i) (subs p i)] (rest pps))
pps)))
-tailcut (fn [cp [p :as ps]] (concat (-slash cp p) (rest ps)))]
(if (or (nil? p1) (nil? p2))
[(-postcut p1s) (-postcut p2s)]
(if-let [cp (and (string? p1) (string? p2) (common-prefix p1 p2))]
[(-tailcut cp p1s) (-tailcut cp p2s)]
[p1s p2s]))))
(defn- -slice-end [x xs]
(let [i (if (string? x) (str/index-of x "/"))]
(if (and (number? i) (pos? ^long i))
(concat [(subs x i)] xs)
xs)))
(defn conflicting-parts? [parts1 parts2]
(let [[[s1 & ss1] [s2 & ss2]] (-slice-start parts1 parts2)]
(cond
(= s1 s2 nil) true
(or (nil? s1) (nil? s2)) false
(or (catch-all? s1) (catch-all? s2)) true
(or (wild? s1) (wild? s2)) (recur (-slice-end s1 ss1) (-slice-end s2 ss2))
(not= s1 s2) false
:else (recur ss1 ss2))))
(defn conflicting-paths? [path1 path2 opts]
(conflicting-parts? (split-path path1 opts) (split-path path2 opts)))
;;
;; Creating Tries
;;
(defn- -node [m]
(map->Node (merge {:children {}, :wilds {}, :catch-all {}, :params {}} m)))
(defn- -insert [node [path & ps] fp params data]
(let [node' (cond
(nil? path)
(assoc node :data data :params params)
(instance? Wild path)
(let [next (first ps)]
(if (or (instance? Wild next) (instance? CatchAll next))
(ex/fail! ::following-parameters {:path fp, :parameters (map :value [path next])})
(update-in node [:wilds path] (fn [n] (-insert (or n (-node {})) ps fp params data)))))
(instance? CatchAll path)
(assoc-in node [:catch-all path] (-node {:params params, :data data}))
(empty? path)
(-insert node ps fp params data)
:else
(or
(reduce
(fn [_ [p n]]
(if-let [cp (common-prefix p path)]
(if (= cp p)
;; insert into child node
(let [n' (-insert n (conj ps (subs path (count p))) fp params data)]
(reduced (assoc-in node [:children p] n')))
;; split child node
(let [rp (subs p (count cp))
rp' (subs path (count cp))
n' (-insert (-node {}) ps fp params data)
n'' (-insert (-node {:children {rp n, rp' n'}}) nil nil nil nil)]
(reduced (update node :children (fn [children]
(-> children
(dissoc p)
(assoc cp n'')))))))))
nil (:children node))
;; new child node
(assoc-in node [:children path] (-insert (-node {}) ps fp params data))))]
(if-let [child (get-in node' [:children ""])]
;; optimize by removing empty paths
(-> (merge-with merge (dissoc node' :data) child)
(update :children dissoc ""))
node')))
(defn- decode [path start end percent?]
(let [param (subs path start end)]
(if percent?
#?(:cljs (js/decodeURIComponent param)
:clj (URLDecoder/decode
(if (.contains ^String param "+")
(.replace ^String param "+" "%2B")
param)
"UTF-8"))
param)))
;;
;; Compilers
;;
(defn clojure-trie-compiler []
(reify
TrieCompiler
(data-matcher [_ params data]
(let [match (->Match params data)]
(reify Matcher
(match [_ i max _]
(if (= i max)
match))
(view [_] data)
(depth [_] 1)
(length [_]))))
(static-matcher [_ path matcher]
(let [size (count path)]
(reify Matcher
(match [_ i max p]
(if-not (< ^long max (+ ^long i size))
(loop [j 0]
(if (= j size)
(match matcher (+ ^long i size) max p)
(if (= (get p (+ ^long i j)) (get path j))
(recur (inc j)))))))
(view [_] [path (view matcher)])
(depth [_] (inc (depth matcher)))
(length [_] (count path)))))
(wild-matcher [_ key end matcher]
(reify Matcher
(match [_ i max path]
(if (and (< ^long i ^long max) (not= (get path i) end))
(loop [percent? false, j ^long i]
(if (= max j)
(if-let [match (match matcher max max path)]
(assoc-param match key (decode path i max percent?)))
(let [c ^char (get path j)]
(condp = c
end (if-let [match (match matcher j max path)]
(assoc-param match key (decode path i j percent?)))
\% (recur true (inc j))
(recur percent? (inc j))))))))
(view [_] [key (view matcher)])
(depth [_] (inc (depth matcher)))
(length [_])))
(catch-all-matcher [_ key params data]
(let [match (->Match params data)]
(reify Matcher
(match [_ i max path]
(if (<= ^long i ^long max) (assoc-param match key (decode path i max true))))
(view [_] [key [data]])
(depth [_] 1)
(length [_]))))
(linear-matcher [_ matchers ordered?]
(let [matchers (vec (if ordered? matchers (reverse (sort-by (juxt depth length) matchers))))
size (count matchers)]
(reify Matcher
(match [_ i max path]
(loop [j 0]
(if (< j size)
(or (match (get matchers j) i max path)
(recur (inc j))))))
(view [_] (mapv view matchers))
(depth [_] (inc ^long (apply max 0 (map depth matchers))))
(length [_]))))
(-pretty [_ matcher]
(view matcher))
(-path-matcher [_ matcher]
(fn [path]
(if-let [match (match matcher 0 (count path) path)]
(->Match (:params match) (:data match)))))))
;#?(:clj
; (defn java-trie-compiler []
; (reify
; TrieCompiler
; (data-matcher [_ params data]
; (Trie/dataMatcher params data))
; (static-matcher [_ path matcher]
; (Trie/staticMatcher ^String path ^Trie$Matcher matcher))
; (wild-matcher [_ key end matcher]
; (Trie/wildMatcher key (if end (Character. end)) matcher))
; (catch-all-matcher [_ key params data]
; (Trie/catchAllMatcher key params data))
; (linear-matcher [_ matchers ordered?]
; (Trie/linearMatcher matchers ordered?))
; (-pretty [_ matcher]
; (-> matcher str read-string eval))
; (-path-matcher [_ matcher]
; (fn [path]
; (if-let [match ^Trie$Match (Trie/lookup ^Trie$Matcher matcher ^String path)]
; (->Match (.params match) (.data match))))))))
;;
;; Managing Tries
;;
(defn- map-parameters [keys]
(zipmap keys (repeat nil)))
#?(:clj
(def record-parameters
"Memoized function to transform parameters into runtime generated Record."
(memoize
(fn [keys]
(if (some qualified-keyword? keys)
(map-parameters keys)
(let [sym (gensym "PathParams")
ctor (symbol (str "map->" sym))]
(binding [*ns* (find-ns 'user)]
(eval `(do (defrecord ~sym ~(mapv (comp symbol name) keys)) (~ctor {}))))))))))
(defn insert
"Returns a trie with routes added to it."
([routes]
(insert nil routes))
([node routes]
(reduce
(fn [acc [p d]]
(insert acc p d))
node routes))
([node path data]
(insert node path data nil))
([node path data {::keys [parameters] :or {parameters map-parameters} :as opts}]
(let [parts (split-path path opts)
params (parameters (->> parts (remove string?) (map :value)))]
(-insert (or node (-node {})) (split-path path opts) path params data))))
(defn compiler
"Returns a default [[TrieCompiler]]."
[]
#?(:cljs (clojure-trie-compiler)
:clj (clojure-trie-compiler) #_(java-trie-compiler)))
(defn compile
"Returns a compiled trie, to be used with [[pretty]] or [[path-matcher]]."
([options]
(compile options (compiler)))
([options compiler]
(compile options compiler []))
([{:keys [data params children wilds catch-all] :or {params {}}} compiler cp]
(let [ends (fn [{:keys [children]}] (or (keys children) ["/"]))
matchers (-> []
(cond-> data (conj (data-matcher compiler params data)))
(into (for [[p c] children] (static-matcher compiler p (compile c compiler (conj cp p)))))
(into
(for [[p c] wilds]
(let [pv (:value p)
ends (ends c)]
(if (next ends)
(ex/fail! ::multiple-terminators {:terminators ends, :path (join-path (conj cp p))})
(wild-matcher compiler pv (ffirst ends) (compile c compiler (conj cp pv)))))))
(into (for [[p c] catch-all] (catch-all-matcher compiler (:value p) params (:data c)))))]
(cond
(> (count matchers) 1) (linear-matcher compiler matchers false)
(= (count matchers) 1) (first matchers)))))
(defn pretty
"Returns a simplified EDN structure of a compiled trie for printing purposes."
([compiled-trie]
(pretty compiled-trie (compiler)))
([compiled-trie compiler]
(-pretty compiler compiled-trie)))
(defn path-matcher
"Returns a function of `path -> Match` from a compiled trie."
([compiled-trie]
(path-matcher compiled-trie (compiler)))
([compiled-trie compiler]
(-path-matcher compiler compiled-trie)))
;;
;; spike
;;
#_(comment
(->
[["/v2/whoami" 1]
["/v2/users/:user-id/datasets" 2]
["/v2/public/projects/:project-id/datasets" 3]
["/v1/public/topics/:topic" 4]
["/v1/users/:user-id/orgs/:org-id" 5]
["/v1/search/topics/:term" 6]
["/v1/users/:user-id/invitations" 7]
["/v1/users/:user-id/topics" 9]
["/v1/users/:user-id/bookmarks/followers" 10]
["/v2/datasets/:dataset-id" 11]
["/v1/orgs/:org-id/usage-stats" 12]
["/v1/orgs/:org-id/devices/:client-id" 13]
["/v1/messages/user/:user-id" 14]
["/v1/users/:user-id/devices" 15]
["/v1/public/users/:user-id" 16]
["/v1/orgs/:org-id/errors" 17]
["/v1/public/orgs/:org-id" 18]
["/v1/orgs/:org-id/invitations" 19]
["/v1/users/:user-id/device-errors" 22]
["/v2/login" 23]
["/v1/users/:user-id/usage-stats" 24]
["/v2/users/:user-id/devices" 25]
["/v1/users/:user-id/claim-device/:client-id" 26]
["/v2/public/projects/:project-id" 27]
["/v2/public/datasets/:dataset-id" 28]
["/v2/users/:user-id/topics/bulk" 29]
["/v1/messages/device/:client-id" 30]
["/v1/users/:user-id/owned-orgs" 31]
["/v1/topics/:topic" 32]
["/v1/users/:user-id/bookmark/:topic" 33]
["/v1/orgs/:org-id/members/:user-id" 34]
["/v1/users/:user-id/devices/:client-id" 35]
["/v1/users/:user-id" 36]
["/v1/orgs/:org-id/devices" 37]
["/v1/orgs/:org-id/members" 38]
["/v2/orgs/:org-id/topics" 40]
["/v1/whoami" 41]
["/v1/orgs/:org-id" 42]
["/v1/users/:user-id/api-key" 43]
["/v2/schemas" 44]
["/v2/users/:user-id/topics" 45]
["/v1/orgs/:org-id/confirm-membership/:token" 46]
["/v2/topics/:topic" 47]
["/v1/messages/topic/:topic" 48]
["/v1/users/:user-id/devices/:client-id/reset-password" 49]
["/v2/topics" 50]
["/v1/login" 51]
["/v1/users/:user-id/orgs" 52]
["/v2/public/messages/dataset/:dataset-id" 53]
["/v1/topics" 54]
["/v1/orgs" 55]
["/v1/users/:user-id/bookmarks" 56]
["/v1/orgs/:org-id/topics" 57]
["/command1 {arg1} {arg2}" ::cmd1]
["/command2 {arg1} {arg2} {arg3}" ::cmd2]]
(insert)
(compile)
(pretty)))
(require 'reitit.impl)
(ns reitit.impl)
;; Babashka doesn't like the fast-assoc implementation
(defn fast-assoc
[a k v] (assoc a k v))
;; --- END Reitit monkey patch
;; DEMO APP
;; Not sure what `muuntaja.protocols` does, but BB doesn't like everything
(ns muuntaja.protocols)
(def ->StreamableResponse identity)
(defprotocol IntoInputStream
(into-input-stream ^java.io.InputStream [this]))
(extend-protocol IntoInputStream
(Class/forName "[B")
(into-input-stream [this] (java.io.ByteArrayInputStream. this))
File
(into-input-stream [this] (java.io.FileInputStream. this))
java.io.InputStream
(into-input-stream [this] this)
;StreamableResponse
;(into-input-stream [this]
; (io/make-input-stream this nil))
String
(into-input-stream [this]
(java.io.ByteArrayInputStream. (.getBytes this "utf-8")))
nil
(into-input-stream [_]
(java.io.ByteArrayInputStream. (byte-array 0))))
(ns muuntaja.format.json
(:require [cheshire.core :as json]
[muuntaja.format.core :as core]))
(defn decoder [options]
(let [] #_[mapper (object-mapper! options)]
(reify
core/Decode
(decode [_ data charset]
(json/generate-string data)
#_(if (.equals "utf-8" ^String charset)
(j/read-value data mapper)
(j/read-value (InputStreamReader. ^InputStream data ^String charset) mapper))))))
(defn encoder [options]
(let [] #_[mapper (object-mapper! options)]
(reify
core/EncodeToBytes
(encode-to-bytes [_ data charset]
#_(if (.equals "utf-8" ^String charset)
(j/write-value-as-bytes data mapper)
(.getBytes ^String (j/write-value-as-string data mapper) ^String charset)))
core/EncodeToOutputStream
(encode-to-output-stream [_ data charset]
#_(fn [^OutputStream output-stream]
(if (.equals "utf-8" ^String charset)
(j/write-value output-stream data mapper)
(j/write-value (OutputStreamWriter. output-stream ^String charset) data mapper)))))))
(def format
(core/map->Format
{:name "application/json"
:decoder [decoder {:decode-key-fn true}]
:encoder [encoder]}))
(ns test-server.core
(:require [reitit.ring :as ring]
[org.httpkit.server :as http]
[reitit.openapi :as openapi]
;; TODO Something is not right with muuntaja, so no json
#_[reitit.ring.middleware.muuntaja :as muuntaja]
#_[muuntaja.core :as m]))
(def routes
[["/openapi.json"
{:get {:openapi {:info {:title "Some tool server API"
:description "reitit + openapi3"
:version "0.0.1"}
:tags [{:name "api"
:description "the api"}]}
:handler (openapi/create-openapi-handler)}}]
["/api"
{:tags ["api"]}
["/hello"
{:get {:summary "hello"
:handler (fn [_]
{:status 200
:body "hello world"})}}]
["/plus"
{:post {:summary "plus with malli body parameters"
:description "description here"
:parameters {:body {:x :int, :y :int}}
:responses {200 {:body {:total :int}}}
:handler (fn [request]
(let [{:keys [x y]} (-> request :parameters :body)]
{:status 200
:body {:total (+ x y)}}))}}]]])
(def app
(ring/ring-handler
(ring/router
routes
#_{:data {:muuntaja m/instance
:middleware [muuntaja/format-response-middleware]}})))
(defn -main []
(http/run-server app {:port 3000})
(println "Server started at http://localhost:3000"))
;;;
(when (= *file* (System/getProperty "babashka.file"))
(apply -main *command-line-args*))
@jeroenvandijk
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jeroenvandijk commented Oct 30, 2025

http://localhost:3000/openapi.json gives output

[:openapi "3.1.0"][:x-id #{:reitit.openapi/default}][:info {:title "Some tool server API", :description "reitit + openapi3", :version "0.0.1"}][:tags [{:name "api", :description "the api"}]][:paths {"/openapi.json" {:get {:tags [{:name "api", :description "the api"}]}}, "/api/hello" {:get {:tags ["api"], :summary "hello"}}, "/api/plus" {:post {:tags ["api"], :summary "plus with malli body parameters", :description "description here"}}}]

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