Improve proxyApplyFn helper scriptlet

gorhill · gorhill · commit 18a8fc7675cc · 2026-01-25T15:57:21.000-05:00
diff --git a/src/js/resources/json-prune.js b/src/js/resources/json-prune.js
@@ -42,32 +42,31 @@ function jsonPrune(
     const logPrefix = safe.makeLogPrefix('json-prune', rawPrunePaths, rawNeedlePaths, stackNeedle);
     const stackNeedleDetails = safe.initPattern(stackNeedle, { canNegate: true });
     const extraArgs = safe.getExtraArgs(Array.from(arguments), 3);
-    JSON.parse = new Proxy(JSON.parse, {
-        apply: function(target, thisArg, args) {
-            const objBefore = Reflect.apply(target, thisArg, args);
-            if ( rawPrunePaths === '' ) {
-                safe.uboLog(logPrefix, safe.JSON_stringify(objBefore, null, 2));
-            }
-            const objAfter = objectPruneFn(
-                objBefore,
-                rawPrunePaths,
-                rawNeedlePaths,
-                stackNeedleDetails,
-                extraArgs
-            );
-            if ( objAfter === undefined ) { return objBefore; }
-            safe.uboLog(logPrefix, 'Pruned');
-            if ( safe.logLevel > 1 ) {
-                safe.uboLog(logPrefix, `After pruning:\n${safe.JSON_stringify(objAfter, null, 2)}`);
-            }
-            return objAfter;
-        },
+    proxyApplyFn('JSON.parse', function(context) {
+        const objBefore = context.reflect();
+        if ( rawPrunePaths === '' ) {
+            safe.uboLog(logPrefix, safe.JSON_stringify(objBefore, null, 2));
+        }
+        const objAfter = objectPruneFn(
+            objBefore,
+            rawPrunePaths,
+            rawNeedlePaths,
+            stackNeedleDetails,
+            extraArgs
+        );
+        if ( objAfter === undefined ) { return objBefore; }
+        safe.uboLog(logPrefix, 'Pruned');
+        if ( safe.logLevel > 1 ) {
+            safe.uboLog(logPrefix, `After pruning:\n${safe.JSON_stringify(objAfter, null, 2)}`);
+        }
+        return objAfter;
     });
 }
 registerScriptlet(jsonPrune, {
     name: 'json-prune.js',
     dependencies: [
         objectPruneFn,
+        proxyApplyFn,
         safeSelf,
     ],
 });
diff --git a/src/js/resources/proxy-apply.js b/src/js/resources/proxy-apply.js
@@ -86,27 +86,38 @@ export function proxyApplyFn(
             }
         };
         proxyApplyFn.isCtor = new Map();
+        proxyApplyFn.proxies = new WeakMap();
+        proxyApplyFn.nativeToString = Function.prototype.toString;
+        const proxiedToString = new Proxy(Function.prototype.toString, {
+            apply(target, thisArg) {
+                let proxied = thisArg;
+                for(;;) {
+                    const fn = proxyApplyFn.proxies.get(proxied);
+                    if ( fn === undefined ) { break; }
+                    proxied = fn;
+                }
+                return proxyApplyFn.nativeToString.call(proxied);
+            }
+        });
+        proxyApplyFn.proxies.set(proxiedToString, proxyApplyFn.nativeToString);
+        Function.prototype.toString = proxiedToString;
     }
     if ( proxyApplyFn.isCtor.has(target) === false ) {
         proxyApplyFn.isCtor.set(target, fn.prototype?.constructor === fn);
     }
-    const fnStr = fn.toString();
-    const toString = (function toString() { return fnStr; }).bind(null);
     const proxyDetails = {
         apply(target, thisArg, args) {
             return handler(proxyApplyFn.ApplyContext.factory(target, thisArg, args));
-        },
-        get(target, prop) {
-            if ( prop === 'toString' ) { return toString; }
-            return Reflect.get(target, prop);
-        },
+        }
     };
     if ( proxyApplyFn.isCtor.get(target) ) {
         proxyDetails.construct = function(target, args) {
             return handler(proxyApplyFn.CtorContext.factory(target, args));
         };
     }
-    context[prop] = new Proxy(fn, proxyDetails);
+    const proxiedTarget = new Proxy(fn, proxyDetails);
+    proxyApplyFn.proxies.set(proxiedTarget, fn);
+    context[prop] = proxiedTarget;
 }
 registerScriptlet(proxyApplyFn, {
     name: 'proxy-apply.fn',
