Replace "type" with "capabilities" in /json response (#42884)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/42884

## Context

We're introducing the concept of **capability flags** to provide granular control of behaviours in the Inspector Proxy, to replace the recently added `type: 'Legacy' | 'Modern'` target switch.

A capability flag disables a specific feature/hack in the Inspector Proxy layer by indicating that the target supports one or more modern CDP features.

## This diff

This updates the pages response in `jsinspector-modern` to send a capability flags configuration, replacing `InspectorPageType`/`"type"`.

Changelog: [Internal]

Reviewed By: robhogan

Differential Revision: D53355413

fbshipit-source-id: 710f9eb11fcc61ab06bfc3051517dd4dd204c68a

packages/react-native/React/Base/RCTBridge.mm

@@ -430,7 +430,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
                   .integrationName = "iOS Bridge (RCTBridge)",
               });
         },
-        facebook::react::jsinspector_modern::InspectorPageType::Modern);
+        {.nativePageReloads = true});
   }
 
   Class bridgeClass = self.bridgeClass;

packages/react-native/ReactCommon/jsinspector-modern/InspectorInterfaces.cpp

@@ -24,6 +24,13 @@ IRemoteConnection::~IRemoteConnection() {}
 IInspector::~IInspector() {}
 IPageStatusListener::~IPageStatusListener() {}
 
+const folly::dynamic targetCapabilitiesToDynamic(
+    const InspectorTargetCapabilities& capabilities) {
+  return folly::dynamic::object(
+      "nativePageReloads", capabilities.nativePageReloads)(
+      "nativeSourceCodeFetching", capabilities.nativeSourceCodeFetching);
+}
+
 namespace {
 
 class InspectorImpl : public IInspector {
@@ -32,7 +39,7 @@ class InspectorImpl : public IInspector {
       const std::string& title,
       const std::string& vm,
       ConnectFunc connectFunc,
-      InspectorPageType type) override;
+      InspectorTargetCapabilities capabilities) override;
   void removePage(int pageId) override;
 
   std::vector<InspectorPageDescription> getPages() const override;
@@ -51,7 +58,7 @@ class InspectorImpl : public IInspector {
         const std::string& title,
         const std::string& vm,
         ConnectFunc connectFunc,
-        InspectorPageType type);
+        InspectorTargetCapabilities capabilities);
     operator InspectorPageDescription() const;
 
     ConnectFunc getConnectFunc() const;
@@ -61,7 +68,7 @@ class InspectorImpl : public IInspector {
     std::string title_;
     std::string vm_;
     ConnectFunc connectFunc_;
-    InspectorPageType type_;
+    InspectorTargetCapabilities capabilities_;
   };
   mutable std::mutex mutex_;
   int nextPageId_{1};
@@ -74,19 +81,19 @@ InspectorImpl::Page::Page(
     const std::string& title,
     const std::string& vm,
     ConnectFunc connectFunc,
-    InspectorPageType type)
+    InspectorTargetCapabilities capabilities)
     : id_(id),
       title_(title),
       vm_(vm),
       connectFunc_(std::move(connectFunc)),
-      type_(type) {}
+      capabilities_(std::move(capabilities)) {}
 
 InspectorImpl::Page::operator InspectorPageDescription() const {
   return InspectorPageDescription{
       .id = id_,
       .title = title_,
       .vm = vm_,
-      .type = type_,
+      .capabilities = capabilities_,
   };
 }
 
@@ -98,12 +105,13 @@ int InspectorImpl::addPage(
     const std::string& title,
     const std::string& vm,
     ConnectFunc connectFunc,
-    InspectorPageType type) {
+    InspectorTargetCapabilities capabilities) {
   std::scoped_lock lock(mutex_);
 
   int pageId = nextPageId_++;
   assert(pages_.count(pageId) == 0 && "Unexpected duplicate page ID");
-  pages_.emplace(pageId, Page{pageId, title, vm, std::move(connectFunc), type});
+  pages_.emplace(
+      pageId, Page{pageId, title, vm, std::move(connectFunc), capabilities});
 
   return pageId;
 }

packages/react-native/ReactCommon/jsinspector-modern/InspectorInterfaces.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <folly/dynamic.h>
+
 #include <functional>
 #include <memory>
 #include <string>
@@ -31,25 +33,19 @@ class IDestructible {
   virtual ~IDestructible() = 0;
 };
 
-enum class InspectorPageType {
-  Legacy,
-  Modern,
+struct InspectorTargetCapabilities {
+  const bool nativePageReloads = false;
+  const bool nativeSourceCodeFetching = false;
 };
 
-inline const char* pageTypeToString(InspectorPageType type) {
-  switch (type) {
-    case InspectorPageType::Legacy:
-      return "Legacy";
-    case InspectorPageType::Modern:
-      return "Modern";
-  }
-}
+const folly::dynamic targetCapabilitiesToDynamic(
+    const InspectorTargetCapabilities& capabilities);
 
 struct InspectorPageDescription {
   const int id;
   const std::string title;
   const std::string vm;
-  const InspectorPageType type;
+  const InspectorTargetCapabilities capabilities;
 };
 
 // Alias for backwards compatibility.
@@ -106,7 +102,7 @@ class JSINSPECTOR_EXPORT IInspector : public IDestructible {
       const std::string& title,
       const std::string& vm,
       ConnectFunc connectFunc,
-      InspectorPageType type = InspectorPageType::Legacy) = 0;
+      InspectorTargetCapabilities capabilities = {}) = 0;
 
   /// removePage is called by the VM to remove a page from the list of
   /// debuggable pages.

packages/react-native/ReactCommon/jsinspector-modern/InspectorPackagerConnection.cpp

@@ -157,9 +157,15 @@ folly::dynamic InspectorPackagerConnection::Impl::pages() {
   folly::dynamic array = folly::dynamic::array();
 
   for (const auto& page : pages) {
-    array.push_back(folly::dynamic::object("id", std::to_string(page.id))(
-        "title", page.title + " [C++ connection]")(
-        "app", app_)("vm", page.vm)("type", pageTypeToString(page.type)));
+    folly::dynamic pageDescription = folly::dynamic::object;
+    pageDescription["id"] = std::to_string(page.id);
+    pageDescription["title"] = page.title + " [C++ connection]";
+    pageDescription["app"] = app_;
+    pageDescription["vm"] = page.vm;
+    pageDescription["capabilities"] =
+        targetCapabilitiesToDynamic(page.capabilities);
+
+    array.push_back(pageDescription);
   }
   return array;
 }

packages/react-native/ReactCommon/jsinspector-modern/tests/InspectorPackagerConnectionTest.cpp

@@ -203,7 +203,8 @@ TEST_F(InspectorPackagerConnectionTest, TestGetPages) {
       "mock-title",
       "mock-vm",
       localConnections_
-          .lazily_make_unique<std::unique_ptr<IRemoteConnection>>());
+          .lazily_make_unique<std::unique_ptr<IRemoteConnection>>(),
+      {.nativePageReloads = true});
 
   // getPages now reports the page we registered.
   EXPECT_CALL(
@@ -217,7 +218,10 @@ TEST_F(InspectorPackagerConnectionTest, TestGetPages) {
                   AtJsonPtr("/title", Eq("mock-title [C++ connection]")),
                   AtJsonPtr("/vm", Eq("mock-vm")),
                   AtJsonPtr("/id", Eq(std::to_string(pageId))),
-                  AtJsonPtr("/type", Eq("Legacy")))}))))))
+                  AtJsonPtr("/capabilities/nativePageReloads", Eq(true)),
+                  AtJsonPtr(
+                      "/capabilities/nativeSourceCodeFetching",
+                      Eq(false)))}))))))
       .RetiresOnSaturation();
   webSockets_[0]->getDelegate().didReceiveMessage(R"({
       "event": "getPages"

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm

@@ -186,7 +186,7 @@ class RCTHostPageTargetDelegate : public facebook::react::jsinspector_modern::Pa
                   .integrationName = "iOS Bridgeless (RCTHost)",
               });
         },
-        facebook::react::jsinspector_modern::InspectorPageType::Modern);
+        {.nativePageReloads = true});
   }
   if (_instance) {
     RCTLogWarn(