From bfe1ab524ea6132010286d7d298001a2ca560ebe Mon Sep 17 00:00:00 2001
From: Michiel Borkent <michielborkent@gmail.com>
Date: Mon, 2 Dec 2024 14:05:03 +0100
Subject: [PATCH] Fix #585: clj->js (#591)

---
 CHANGELOG.md                   |  6 +++++-
 package.json                   |  2 +-
 resources/squint/core.edn      |  1 +
 src/squint/compiler.cljc       |  4 ----
 src/squint/core.js             | 29 +++++++++++++++++++++++++++++
 test/squint/compiler_test.cljs |  8 ++++++++
 6 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40d474e9..6734d413 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,11 @@
 
 [Squint](https://github.com/squint-cljs/squint): Light-weight ClojureScript dialect
 
-## v0.8.126 (2024-11-29)
+## v0.8.128 (2024-12-02)
+
+- [#585](https://github.com/squint-cljs/squint/issues/585): fix `clj->js` to realize lazy seqs into arrays
+
+## v0.8.127 (2024-11-29)
 
 - [#586](https://github.com/squint-cljs/squint/issues/586): support extending protocol to `nil`
 
diff --git a/package.json b/package.json
index e28f05d5..037d6d02 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "squint-cljs",
   "type": "module",
   "sideEffects": false,
-  "version": "0.8.126",
+  "version": "0.8.127",
   "files": [
     "core.js",
     "src/squint/core.js",
diff --git a/resources/squint/core.edn b/resources/squint/core.edn
index 9fddc6a7..df6f4ddf 100644
--- a/resources/squint/core.edn
+++ b/resources/squint/core.edn
@@ -33,6 +33,7 @@
   bounded_count
   butlast
   cat
+  clj__GT_js
   coll_QMARK_
   comp
   compare
diff --git a/src/squint/compiler.cljc b/src/squint/compiler.cljc
index 794256c0..a4fc93b8 100644
--- a/src/squint/compiler.cljc
+++ b/src/squint/compiler.cljc
@@ -45,7 +45,6 @@
                          'squint-compiler-html
                          'squint.impl/deref
                          'require 'squint.defclass/defclass* 'squint.defclass/super*
-                         'clj->js
                          'squint.impl/for-of
                          'squint.impl/defonce]))
 
@@ -128,9 +127,6 @@
 (defmethod emit-special 'js/typeof [_ env [_ form]]
   (emit-return (str "typeof " (emit form (expr-env env))) env))
 
-(defmethod emit-special 'clj->js [_ env [_ form]]
-  (emit form env))
-
 (defmethod emit-special 'deftype* [_ env [_ t fields pmasks body]]
   (let [fields (map munge fields)]
     (str "var " (munge t) " = " (format "function %s {
diff --git a/src/squint/core.js b/src/squint/core.js
index cdb1c073..78c6023a 100644
--- a/src/squint/core.js
+++ b/src/squint/core.js
@@ -1056,6 +1056,17 @@ export function vector_QMARK_(x) {
 }
 
 export function mapv(...args) {
+  if (args.length === 2) {
+    const [f, coll] = args;
+    if (coll instanceof LazyIterable) {
+      var ret = [];
+      for (const x of coll) {
+        ret.push(f(x));
+      }
+      return ret;
+    }
+    return into([], map(f), coll);
+  }
   return [...map(...args)];
 }
 
@@ -2731,3 +2742,21 @@ export class Delay {
     }
   }
 }
+
+function clj__GT_js_(x, seen) {
+  // we need to protect against circular objects
+  if (seen.has(x)) return x;
+  seen.add(x);
+  if (map_QMARK_(x)) {
+    return update_vals(x, x => clj__GT_js_(x, seen));
+  }
+
+  if (coll_QMARK_(x)) {
+    return mapv(x => clj__GT_js_(x, seen), x);
+  }
+  return x;
+}
+
+export function clj__GT_js(x) {
+  return clj__GT_js_(x, new Set());
+}
diff --git a/test/squint/compiler_test.cljs b/test/squint/compiler_test.cljs
index 37034533..dfc8df23 100644
--- a/test/squint/compiler_test.cljs
+++ b/test/squint/compiler_test.cljs
@@ -2333,5 +2333,13 @@ new Foo();")
   (is (eq [true true false]
           (jsv! "[(map? {}) (map? (new Map [])) (map? [])]"))))
 
+(deftest clj->js-test
+  (is (eq [2 3 4]
+          (jsv! "(clj->js (map inc [1 2 3]))")))
+  (is (eq {:a [2 3 4]}
+          (jsv! "(clj->js {:a (map inc [1 2 3])})")))
+  (is (eq [2 3 4]
+          (jsv! "(def x {:a 1 :b (map inc [1 2 3])}) (set! (.-a x) x) (:b (clj->js x))"))))
+
 (defn init []
   (t/run-tests 'squint.compiler-test 'squint.jsx-test 'squint.string-test 'squint.html-test))