CLJS-1573: Self-host: Invalid UTF escaping in cljs-in-cljs

Zero-pad \u escapes

src/main/clojure/cljs/compiler.cljc

@@ -132,8 +132,10 @@
       9 "\\t"
       (if (< 31 cp 127)
         c ; Print simple ASCII characters
-        #?(:clj (format "\\u%04X" cp)
-           :cljs (str "\\u" (.toString cp 16))))))) ; Any other character is Unicode
+        #?(:clj (format "\\u%04X" cp)                       ; Any other character is Unicode
+           :cljs (let [unpadded (.toString cp 16)
+                       pad      (subs "0000" (.-length unpadded))]
+                   (str "\\u" pad unpadded)))))))
 
 (defn- escape-string [^CharSequence s]
   (let [sb #?(:clj (StringBuilder. (count s))

src/test/self/self_host/test.cljs

@@ -240,6 +240,40 @@
       (is (nil? value))
       (is (= "if-let requires a vector for its binding at line 1 " (ex-message (ex-cause error)))))))
 
+(deftest test-CLJS-1573
+  (cljs/compile-str st
+    "\"90°\""
+    nil
+    {:eval    node-eval
+     :context :expr}
+    (fn [{:keys [error value]}]
+      (is (nil? error))
+      (is (= "\"90\\u00b0\"" value))))
+  (cljs/compile-str st
+    "\"Ϊ\""
+    nil
+    {:eval    node-eval
+     :context :expr}
+    (fn [{:keys [error value]}]
+      (is (nil? error))
+      (is (= "\"\\u03aa\"" value))))
+  (cljs/compile-str st
+    "\"ሴ\""
+    nil
+    {:eval    node-eval
+     :context :expr}
+    (fn [{:keys [error value]}]
+      (is (nil? error))
+      (is (= "\"\\u1234\"" value))))
+  (cljs/eval-str st
+    "\"90°\""
+    nil
+    {:eval node-eval
+     :context :expr}
+    (fn [{:keys [error value]}]
+      (is (nil? error))
+      (is (= "90°" value)))))
+
 #_(deftest test-eval-str-with-require
   (async done
     (let [l (latch 3 done)]