repl: fix getters triggering side effects during completion

PR-URL: #61043
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Aviv Keller <me@aviv.sh>

Author: dario-piotrowicz

lib/internal/repl/completion.js

@@ -731,35 +731,15 @@ function includesProxiesOrGetters(expr, exprStr, evalFn, ctx, callback) {
 
 if(astProp.type==='Literal'){
 // We have something like `obj['foo'].x` where `x` is the literal
-
-if(safeIsProxyAccess(obj,astProp.value)){
-returncb(true);
-}
-
-constpropDescriptor=ObjectGetOwnPropertyDescriptor(
-obj,
-`${astProp.value}`,
-);
-constpropHasGetter=typeofpropDescriptor?.get==='function';
-returncb(propHasGetter);
+returnpropHasGetterOrIsProxy(obj,astProp.value,cb);
 }
 
 if(
 astProp.type==='Identifier'&&
 exprStr.at(astProp.start-1)==='.'
 ){
 // We have something like `obj.foo.x` where `foo` is the identifier
-
-if(safeIsProxyAccess(obj,astProp.name)){
-returncb(true);
-}
-
-constpropDescriptor=ObjectGetOwnPropertyDescriptor(
-obj,
-`${astProp.name}`,
-);
-constpropHasGetter=typeofpropDescriptor?.get==='function';
-returncb(propHasGetter);
+returnpropHasGetterOrIsProxy(obj,astProp.name,cb);
 }
 
 returnevalFn(
@@ -773,37 +753,48 @@ function includesProxiesOrGetters(expr, exprStr, evalFn, ctx, callback) {
 getREPLResourceName(),
 (err,evaledProp)=>{
 if(err){
-returncallback(false);
+returncb(false);
 }
 
 if(typeofevaledProp==='string'){
-if(safeIsProxyAccess(obj,evaledProp)){
-returncb(true);
-}
-
-constpropDescriptor=ObjectGetOwnPropertyDescriptor(
-obj,
-evaledProp,
-);
-constpropHasGetter=typeofpropDescriptor?.get==='function';
-returncb(propHasGetter);
+returnpropHasGetterOrIsProxy(obj,evaledProp,cb);
 }
 
-returncallback(false);
+returncb(false);
 },
 );
 }
 
-functionsafeIsProxyAccess(obj,prop){
-// Accessing `prop` may trigger a getter that throws, so we use try-catch to guard against it
-try{
-returnisProxy(obj[prop]);
-}catch{
-returnfalse;
-}
+returncallback(false);
+}
+
+/**
+ * Given an object and a property name, checks whether the property has a getter, if not checks whether its
+ * value is a proxy.
+ *
+ * Note: the order is relevant here, we want to check whether the property has a getter _before_ we check
+ * whether its value is a proxy, to ensure that is the property does have a getter we don't end up
+ * triggering it when checking its value
+ * @param {any} obj The target object
+ * @param {string | number | bigint | boolean | RegExp} prop The target property
+ * @param {(includes: boolean) => void} cb Callback that will be called with the result of the operation
+ * @returns {void}
+ */
+functionpropHasGetterOrIsProxy(obj,prop,cb){
+constpropDescriptor=ObjectGetOwnPropertyDescriptor(
+obj,
+prop,
+);
+constpropHasGetter=typeofpropDescriptor?.get==='function';
+if(propHasGetter){
+returncb(true);
 }
 
-returncallback(false);
+if(isProxy(obj[prop])){
+returncb(true);
+}
+
+returncb(false);
 }
 
 module.exports={

test/parallel/test-repl-completion-on-getters-disabled.js

@@ -115,6 +115,33 @@ describe('REPL completion in relation of getters', () => {
 ['objWithGetters[getGFooKey()].b',[]],
 ]);
 });
+
+test('no side effects are triggered for getters during completion',async()=>{
+const{ replServer }=startNewREPLServer();
+
+awaitnewPromise((resolve,reject)=>{
+replServer.eval('const foo = { get name() { globalThis.nameGetterRun = true; throw new Error(); } };',
+replServer.context,'',(err)=>{
+if(err){
+reject(err);
+}else{
+resolve();
+}
+});
+});
+
+['foo.name.','foo["name"].'].forEach((test)=>{
+replServer.complete(
+test,
+common.mustCall((error,data)=>{
+// The context's nameGetterRun variable hasn't been set
+assert.strictEqual(replServer.context.nameGetterRun,undefined);
+// No errors has been thrown
+assert.strictEqual(error,null);
+})
+);
+});
+});
 });
 
 describe('completions on proxies',()=>{