Fix #572: prevent vite page reload (#573)

* Fix #572: prevent vite page reload

* changelog

* fix class in REPL

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 [Squint](https://github.com/squint-cljs/squint): Light-weight ClojureScript dialect
 
+## v0.8.123 (2024-11-05)
+
+- Fix [#572](https://github.com/squint-cljs/squint/issues/572): prevent vite page reload
+
 ## v0.8.122 (2024-10-19)
 
 - Fix watcher and compiler not overriding `squint.edn` configurations with

examples/vite-react/bb.edn

@@ -1,5 +1,5 @@
 {:tasks
- {dev:squint (shell "npx squint watch")
+ {dev:squint (shell "npx squint watch --repl true")
   dev:vite (shell "npx vite --config=vite.config.js public")
   -dev {:depends [dev:squint dev:vite]}
   dev (run '-dev {:parallel true})

examples/vite-react/package.json

@@ -9,6 +9,6 @@
   "dependencies": {
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
-    "squint-cljs": "latest"
+    "squint-cljs": "../.."
   }
 }

examples/vite-react/src/my_component.cljs

@@ -1,11 +1,13 @@
 (ns my-component
   (:require ["react" :refer [useState]]))
 
-(defn adder [& n]
-  (apply + n))
+;; this needs to be private since non-component exports break vite react HMR
+(defonce ^:private x 10)
 
 (defn MyComponent []
   (let [[state setState] (useState 0)]
     #jsx [:div "You clicked " state " times"
-          [:button {:onClick #(setState (inc state))}
+          [:button {:onClick #(do
+                                (set! x (inc x))
+                                (setState (inc state)))}
            "Click me"]]))

src/squint/compiler.cljc

@@ -453,10 +453,10 @@
                            (str
                             (when-let [vars (disj @public-vars "default$")]
                               (when (seq vars)
-                                (if cc/*repl*
+                                (if false #_cc/*repl*
                                   (str/join "\n"
                                             (map (fn [var]
-                                                   (str "export const " var " = " (munge cc/*cljs-ns*) "." var ";"))
+                                                   (str "export " var ";"))
                                                  vars))
                                   (format "\nexport { %s }\n"
                                           (str/join ", " vars)))))

src/squint/compiler_common.cljc

@@ -475,13 +475,13 @@
   (let [expr (if (= 3 (count expr))
                ?expr ?doc)
         env (no-top-level env)]
-    (str (if *repl*
+    (str (str "var " (munge name)) " = "
+         (emit expr (expr-env env)) ";\n"
+         (when *repl*
            (str "globalThis."
                 (when *cljs-ns*
                   (str (munge *cljs-ns*) ".") #_"var ")
-                (munge name))
-           (str "var " (munge name))) " = "
-         (emit expr (expr-env env)) ";\n")))
+                (munge name) " = " (munge name) ";\n")))))
 
 (defmethod emit-special 'def [_type env [_const & more :as expr]]
   (let [name (first more)]

src/squint/defclass.cljc

@@ -160,6 +160,7 @@
   (let [env (assoc env* :context :statement)
         {:keys [classname extends extend constructor fields protocols] :as _all} (parse-class (rest form))
         [_ ctor-args & ctor-body] constructor
+        classname* (symbol (str classname "$"))
         _ (assert (pos? (count ctor-args)) "contructor requires at least one argument name for this")
 
         [this-sym & ctor-args] ctor-args
@@ -189,7 +190,7 @@
                (mapcat identity)))]
     (str
      "class "
-     (munge classname)
+     (munge classname*)
      (when extends
        (str " extends "
             (emit-fn extends env)))
@@ -206,8 +207,8 @@
      (str (emit-fn extend-form fields-env))
      (when extend
        (str extend))
-     (when (:repl env)
-       (emit-fn (list 'def classname (list 'js* (munge classname))) env))
+     (when true #_(:repl env)
+       (emit-fn (list 'def classname (list 'js* (munge classname*))) env))
      (when (= :return (:context env*))
        (str "return " (munge classname) ";")))))