src: disallow constructor behaviour for native methods

Disallow constructor behaviour and setting up prototypes
for native methods that are not constructors (i.e. make
them behave like ES6 class methods).

PR-URL: nodejs#26700
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/env-inl.h

@@ -883,9 +883,7 @@ inline void Environment::SetMethod(v8::Local<v8::Object> that,
   v8::Local<v8::Context> context = isolate()->GetCurrentContext();
   v8::Local<v8::Function> function =
       NewFunctionTemplate(callback, v8::Local<v8::Signature>(),
-                          // TODO(TimothyGu): Investigate if SetMethod is ever
-                          // used for constructors.
-                          v8::ConstructorBehavior::kAllow,
+                          v8::ConstructorBehavior::kThrow,
                           v8::SideEffectType::kHasSideEffect)
           ->GetFunction(context)
           .ToLocalChecked();
@@ -903,9 +901,7 @@ inline void Environment::SetMethodNoSideEffect(v8::Local<v8::Object> that,
   v8::Local<v8::Context> context = isolate()->GetCurrentContext();
   v8::Local<v8::Function> function =
       NewFunctionTemplate(callback, v8::Local<v8::Signature>(),
-                          // TODO(TimothyGu): Investigate if SetMethod is ever
-                          // used for constructors.
-                          v8::ConstructorBehavior::kAllow,
+                          v8::ConstructorBehavior::kThrow,
                           v8::SideEffectType::kHasNoSideEffect)
           ->GetFunction(context)
           .ToLocalChecked();

test/parallel/test-process-chdir.js

@@ -42,3 +42,8 @@ const err = {
 };
 common.expectsError(function() { process.chdir({}); }, err);
 common.expectsError(function() { process.chdir(); }, err);
+
+// Check that our built-in methods do not have a prototype/constructor behaviour
+// if they don't need to. This could be tested for any of our C++ methods.
+assert.strictEqual(process.cwd.prototype, undefined);
+assert.throws(() => new process.cwd(), TypeError);