[debugger] Report function proxies as proxies, not as functions

This CL fixes a bug where function proxies were reported as functions
instead as proxies to devtools, which caused dev-tools to call methods
on the function, possibly triggering side-effects.

Change-Id: I1d5d234b784601bd4b7ec91107e4b0cf0d877d07
Bug: chromium:995753
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1762303Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63307}

src/inspector/value-mirror.cc

@@ -1614,13 +1614,13 @@ std::unique_ptr<ValueMirror> ValueMirror::create(v8::Local<v8::Context> context,
         value, RemoteObject::SubtypeEnum::Regexp,
         descriptionForRegExp(isolate, value.As<v8::RegExp>()));
   }
-  if (value->IsFunction()) {
-    return v8::base::make_unique<FunctionMirror>(value);
-  }
   if (value->IsProxy()) {
     return v8::base::make_unique<ObjectMirror>(
         value, RemoteObject::SubtypeEnum::Proxy, "Proxy");
   }
+  if (value->IsFunction()) {
+    return v8::base::make_unique<FunctionMirror>(value);
+  }
   if (value->IsDate()) {
     return v8::base::make_unique<ObjectMirror>(
         value, RemoteObject::SubtypeEnum::Date,

test/inspector/debugger/object-preview-internal-properties-expected.txt

@@ -259,6 +259,7 @@ expression: Promise.resolve(42)
     value : 42
 }
 
+
 Running test: privateNames
 expression: new class { #foo = 1; #bar = 2; baz = 3;}
 {
@@ -295,3 +296,18 @@ expression: new class extends class { #baz = 3; } { #foo = 1; #bar = 2; }
 }
 
 expression: new class extends class { constructor() { return new Proxy({}, {}); } } { #foo = 1; #bar = 2; }
+
+
+Running test: functionProxy
+expression: new Proxy(() => {}, { get: () => x++ })
+{
+    name : length
+    type : number
+    value : 0
+}
+{
+    name : name
+    type : string
+    value : 
+}
+

test/inspector/debugger/object-preview-internal-properties.js

@@ -82,6 +82,12 @@ InspectorTest.runTestSuite([
       .then(() => checkExpression("new class extends class { #baz = 3; } { #foo = 1; #bar = 2; }"))
       .then(() => checkExpression("new class extends class { constructor() { return new Proxy({}, {}); } } { #foo = 1; #bar = 2; }"))
       .then(next);
+  },
+
+  function functionProxy(next)
+  {
+    checkExpression("new Proxy(() => {}, { get: () => x++ })")
+      .then(next);
   }
 ]);