Reorganize v8 contexts and scope

- Pages within the same session have proper isolation
  - they have their own window
  - they have their own SessionState
  - they have their own v8.Context

- Move inspector to CDP browser context
  - Browser now knows nothing about the inspector

- Use notification to emit a context-created message
  - This is still a bit hacky, but again, it decouples browser from CDP

Author: karlseguin

src/browser/browser.zig

@@ -114,7 +114,7 @@ pub const MutationObserver = struct {
         }
     }
 
-    pub fn jsScopeEnd(self: *MutationObserver, _: anytype) void {
+    pub fn jsCallScopeEnd(self: *MutationObserver, _: anytype) void {
         const record = self.observed.items;
         if (record.len == 0) {
             return;

src/browser/dom/mutation_observer.zig

@@ -25,6 +25,7 @@ pub const JsThis = Env.JsThis;
 pub const JsObject = Env.JsObject;
 pub const Callback = Env.Callback;
 pub const Env = js.Env(*SessionState, Interfaces{});
+pub const Global = @import("html/window.zig").Window;
 
 pub const SessionState = struct {
     loop: *Loop,

src/browser/env.zig

@@ -17,7 +17,7 @@ test "Browser.fetch" {
     var runner = try testing.jsRunner(testing.tracking_allocator, .{});
     defer runner.deinit();
 
-    try @import("polyfill.zig").load(testing.allocator, runner.executor);
+    try @import("polyfill.zig").load(testing.allocator, runner.scope);
 
     try runner.testCases(&.{
         .{

src/browser/polyfill/fetch.zig

@@ -31,13 +31,13 @@ const modules = [_]struct {
     .{ .name = "polyfill-fetch", .source = @import("fetch.zig").source },
 };
 
-pub fn load(allocator: Allocator, executor: *Env.Executor) !void {
+pub fn load(allocator: Allocator, scope: *Env.Scope) !void {
     var try_catch: Env.TryCatch = undefined;
-    try_catch.init(executor);
+    try_catch.init(scope);
     defer try_catch.deinit();
 
     for (modules) |m| {
-        const res = executor.exec(m.source, m.name) catch |err| {
+        const res = scope.exec(m.source, m.name) catch |err| {
             if (try try_catch.err(allocator)) |msg| {
                 defer allocator.free(msg);
                 log.err("load {s}: {s}", .{ m.name, msg });

src/browser/polyfill/polyfill.zig

@@ -25,6 +25,7 @@ const Env = @import("../browser/env.zig").Env;
 const asUint = @import("../str/parser.zig").asUint;
 const Browser = @import("../browser/browser.zig").Browser;
 const Session = @import("../browser/browser.zig").Session;
+const Inspector = @import("../browser/env.zig").Env.Inspector;
 const Incrementing = @import("../id.zig").Incrementing;
 const Notification = @import("../notification.zig").Notification;
 
@@ -309,40 +310,51 @@ pub fn BrowserContext(comptime CDP_T: type) type {
         node_registry: Node.Registry,
         node_search_list: Node.Search.List,
 
-        isolated_world: ?IsolatedWorld(Env),
+        inspector: Inspector,
+        isolated_world: ?IsolatedWorld,
 
         const Self = @This();
 
         fn init(self: *Self, id: []const u8, cdp: *CDP_T) !void {
             const allocator = cdp.allocator;
 
+            const session = try cdp.browser.newSession(self);
+            const arena = session.arena.allocator();
+
+            const inspector = try cdp.browser.env.newInspector(arena, self);
+
             var registry = Node.Registry.init(allocator);
             errdefer registry.deinit();
 
-            const session = try cdp.browser.newSession(self);
             self.* = .{
                 .id = id,
                 .cdp = cdp,
+                .arena = arena,
                 .target_id = null,
                 .session_id = null,
+                .session = session,
                 .security_origin = URL_BASE,
                 .secure_context_type = "Secure", // TODO = enum
                 .loader_id = LOADER_ID,
-                .session = session,
-                .arena = session.arena.allocator(),
                 .page_life_cycle_events = false, // TODO; Target based value
                 .node_registry = registry,
                 .node_search_list = undefined,
                 .isolated_world = null,
+                .inspector = inspector,
             };
             self.node_search_list = Node.Search.List.init(allocator, &self.node_registry);
         }
 
         pub fn deinit(self: *Self) void {
-            if (self.isolated_world) |isolated_world| {
-                isolated_world.executor.endScope();
-                self.cdp.browser.env.stopExecutor(isolated_world.executor);
-                self.isolated_world = null;
+            self.inspector.deinit();
+
+            // If the session has a page, we need to clear it first. The page
+            // context is always nested inside of the isolated world context,
+            // so we need to shutdown the page one first.
+            self.cdp.browser.closeSession();
+
+            if (self.isolated_world) |*world| {
+                world.deinit();
             }
             self.node_registry.deinit();
             self.node_search_list.deinit();
@@ -353,25 +365,25 @@ pub fn BrowserContext(comptime CDP_T: type) type {
             self.node_search_list.reset();
         }
 
-        pub fn createIsolatedWorld(
-            self: *Self,
-            world_name: []const u8,
-            grant_universal_access: bool,
-        ) !void {
-            if (self.isolated_world != null) return error.CurrentlyOnly1IsolatedWorldSupported;
-
-            const executor = try self.cdp.browser.env.startExecutor(@import("../browser/html/window.zig").Window, &self.session.state, self.session, .isolated);
-            errdefer self.cdp.browser.env.stopExecutor(executor);
+        pub fn createIsolatedWorld(self: *Self) !void {
+            if (self.isolated_world != null) {
+                return error.CurrentlyOnly1IsolatedWorldSupported;
+            }
 
-            // TBD should we endScope on removePage and re-startScope on createPage?
-            // Window will be refactored into the executor so we leave it ugly here for now as a reminder.
-            try executor.startScope(@import("../browser/html/window.zig").Window{});
+            var executor = try self.cdp.browser.env.newExecutor();
+            errdefer executor.deinit();
 
             self.isolated_world = .{
-                .name = try self.arena.dupe(u8, world_name),
-                .grant_universal_access = grant_universal_access,
+                .name = "",
+                .global = .{},
+                .scope = undefined,
                 .executor = executor,
+                .grant_universal_access = false,
             };
+            var world = &self.isolated_world.?;
+
+            // TODO: can we do something better than passing `undefined` for the state?
+            world.scope = try world.executor.startScope(&world.global, undefined, {});
         }
 
         pub fn nodeWriter(self: *Self, node: *const Node, opts: Node.Writer.Opts) Node.Writer {
@@ -384,18 +396,35 @@ pub fn BrowserContext(comptime CDP_T: type) type {
 
         pub fn getURL(self: *const Self) ?[]const u8 {
             const page = self.session.currentPage() orelse return null;
-            return if (page.url) |*url| url.raw else null;
+            const raw_url = page.url.raw;
+            return if (raw_url.len == 0) null else raw_url;
         }
 
         pub fn notify(ctx: *anyopaque, notification: *const Notification) !void {
             const self: *Self = @alignCast(@ptrCast(ctx));
 
             switch (notification.*) {
+                .context_created => |cc| {
+                    const aux_data = try std.fmt.allocPrint(self.arena, "{{\"isDefault\":true,\"type\":\"default\",\"frameId\":\"{s}\"}}", .{self.target_id.?});
+                    self.inspector.contextCreated(
+                        self.session.page.?.scope,
+                        "",
+                        cc.origin,
+                        aux_data,
+                        true,
+                    );
+                },
                 .page_navigate => |*pn| return @import("domains/page.zig").pageNavigate(self, pn),
                 .page_navigated => |*pn| return @import("domains/page.zig").pageNavigated(self, pn),
             }
         }
 
+        pub fn callInspector(self: *const Self, msg: []const u8) void {
+            self.inspector.send(msg);
+            // force running micro tasks after send input to the inspector.
+            self.cdp.browser.runMicrotasks();
+        }
+
         pub fn onInspectorResponse(ctx: *anyopaque, _: u32, msg: []const u8) void {
             if (std.log.defaultLogEnabled(.debug)) {
                 // msg should be {"id":<id>,...
@@ -481,13 +510,17 @@ pub fn BrowserContext(comptime CDP_T: type) type {
 /// An isolated world has it's own instance of globals like Window.
 /// Generally the client needs to resolve a node into the isolated world to be able to work with it.
 /// An object id is unique across all contexts, different object ids can refer to the same Node in different contexts.
-pub fn IsolatedWorld(comptime E: type) type {
-    return struct {
-        name: []const u8,
-        grant_universal_access: bool,
-        executor: *E.Executor,
-    };
-}
+const IsolatedWorld = struct {
+    name: []const u8,
+    scope: *Env.Scope,
+    executor: Env.Executor,
+    grant_universal_access: bool,
+    global: @import("../browser/html/window.zig").Window,
+
+    pub fn deinit(self: *IsolatedWorld) void {
+        self.executor.deinit();
+    }
+};
 
 // This is a generic because when we send a result we have two different
 // behaviors. Normally, we're sending the result to the client. But in some cases

src/cdp/cdp.zig

@@ -127,24 +127,27 @@ fn resolveNode(cmd: anytype) !void {
         objectGroup: ?[]const u8 = null,
         executionContextId: ?u32 = null,
     })) orelse return error.InvalidParams;
+
     const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
+    const page = bc.session.currentPage() orelse return error.PageNotLoaded;
 
-    var executor = bc.session.executor;
+    var scope = page.scope;
     if (params.executionContextId) |context_id| {
-        if (executor.context.debugContextId() != context_id) {
+        if (scope.context.debugContextId() != context_id) {
             const isolated_world = bc.isolated_world orelse return error.ContextNotFound;
-            executor = isolated_world.executor;
+            scope = isolated_world.scope;
 
-            if (executor.context.debugContextId() != context_id) return error.ContextNotFound;
+            if (scope.context.debugContextId() != context_id) return error.ContextNotFound;
         }
     }
-    const input_node_id = if (params.nodeId) |node_id| node_id else params.backendNodeId orelse return error.InvalidParams;
+
+    const input_node_id = params.nodeId orelse params.backendNodeId orelse return error.InvalidParam;
     const node = bc.node_registry.lookup_by_id.get(input_node_id) orelse return error.UnknownNode;
 
     // node._node is a *parser.Node we need this to be able to find its most derived type e.g. Node -> Element -> HTMLElement
     // So we use the Node.Union when retrieve the value from the environment
-    const remote_object = try bc.session.inspector.getRemoteObject(
-        executor,
+    const remote_object = try bc.inspector.getRemoteObject(
+        scope,
         params.objectGroup orelse "",
         try dom_node.Node.toInterface(node._node),
     );
@@ -163,28 +166,61 @@ fn resolveNode(cmd: anytype) !void {
 fn describeNode(cmd: anytype) !void {
     const params = (try cmd.params(struct {
         nodeId: ?Node.Id = null,
-        backendNodeId: ?Node.Id = null,
-        objectId: ?[]const u8 = null,
-        depth: u32 = 1,
-        pierce: bool = false,
+        backendNodeId: ?u32 = null,
+        objectGroup: ?[]const u8 = null,
+        executionContextId: ?u32 = null,
     })) orelse return error.InvalidParams;
-    if (params.backendNodeId != null or params.depth != 1 or params.pierce) {
+
+    if (params.nodeId == null or params.backendNodeId != null or params.executionContextId != null) {
         return error.NotYetImplementedParams;
     }
 
     const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
+    const page = bc.session.currentPage() orelse return error.PageNotLoaded;
+    const node = bc.node_registry.lookup_by_id.get(params.nodeId.?) orelse return error.UnknownNode;
 
-    if (params.nodeId != null) {
-        const node = bc.node_registry.lookup_by_id.get(params.nodeId.?) orelse return error.NodeNotFound;
-        return cmd.sendResult(.{ .node = bc.nodeWriter(node, .{}) }, .{});
-    }
-    if (params.objectId != null) {
-        // Retrieve the object from which ever context it is in.
-        const parser_node = try bc.session.inspector.getNodePtr(cmd.arena, params.objectId.?);
-        const node = try bc.node_registry.register(@ptrCast(parser_node));
-        return cmd.sendResult(.{ .node = bc.nodeWriter(node, .{}) }, .{});
-    }
-    return error.MissingParams;
+    // node._node is a *parser.Node we need this to be able to find its most derived type e.g. Node -> Element -> HTMLElement
+    // So we use the Node.Union when retrieve the value from the environment
+    const remote_object = try bc.inspector.getRemoteObject(
+        page.scope,
+        params.objectGroup orelse "",
+        try dom_node.Node.toInterface(node._node),
+    );
+    defer remote_object.deinit();
+
+    const arena = cmd.arena;
+    return cmd.sendResult(.{ .object = .{
+        .type = try remote_object.getType(arena),
+        .subtype = try remote_object.getSubtype(arena),
+        .className = try remote_object.getClassName(arena),
+        .description = try remote_object.getDescription(arena),
+        .objectId = try remote_object.getObjectId(arena),
+    } }, .{});
+
+    // const params = (try cmd.params(struct {
+    //     nodeId: ?Node.Id = null,
+    //     backendNodeId: ?Node.Id = null,
+    //     objectId: ?[]const u8 = null,
+    //     depth: u32 = 1,
+    //     pierce: bool = false,
+    // })) orelse return error.InvalidParams;
+    // if (params.backendNodeId != null or params.depth != 1 or params.pierce) {
+    //     return error.NotYetImplementedParams;
+    // }
+
+    // const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
+
+    // if (params.nodeId != null) {
+    //     const node = bc.node_registry.lookup_by_id.get(params.nodeId.?) orelse return error.NodeNotFound;
+    //     return cmd.sendResult(.{ .node = bc.nodeWriter(node, .{}) }, .{});
+    // }
+    // if (params.objectId != null) {
+    //     // Retrieve the object from which ever context it is in.
+    //     const parser_node = try bc.session.inspector.getNodePtr(cmd.arena, params.objectId.?);
+    //     const node = try bc.node_registry.register(@ptrCast(parser_node));
+    //     return cmd.sendResult(.{ .node = bc.nodeWriter(node, .{}) }, .{});
+    // }
+    // return error.MissingParams;
 }
 
 const testing = @import("../testing.zig");

src/cdp/domains/dom.zig

@@ -112,15 +112,15 @@ fn createIsolatedWorld(cmd: anytype) !void {
     }
     const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
 
-    try bc.createIsolatedWorld(params.worldName, params.grantUniveralAccess);
     const world = &bc.isolated_world.?;
-
+    world.name = try bc.arena.dupe(u8, params.worldName);
+    world.grant_universal_access = params.grantUniveralAccess;
     // Create the auxdata json for the contextCreated event
     // Calling contextCreated will assign a Id to the context and send the contextCreated event
     const aux_data = try std.fmt.allocPrint(cmd.arena, "{{\"isDefault\":false,\"type\":\"isolated\",\"frameId\":\"{s}\"}}", .{params.frameId});
-    bc.session.inspector.contextCreated(world.executor, world.name, "", aux_data, false);
+    bc.inspector.contextCreated(world.scope, world.name, "", aux_data, false);
 
-    return cmd.sendResult(.{ .executionContextId = world.executor.context.debugContextId() }, .{});
+    return cmd.sendResult(.{ .executionContextId = world.scope.context.debugContextId() }, .{});
 }
 
 fn navigate(cmd: anytype) !void {
@@ -222,8 +222,8 @@ pub fn pageNavigate(bc: anytype, event: *const Notification.PageNavigate) !void
         const aux_json = try std.fmt.bufPrint(&buffer, "{{\"isDefault\":false,\"type\":\"isolated\",\"frameId\":\"{s}\"}}", .{bc.target_id.?});
 
         // Calling contextCreated will assign a new Id to the context and send the contextCreated event
-        bc.session.inspector.contextCreated(
-            isolated_world.executor,
+        bc.inspector.contextCreated(
+            isolated_world.scope,
             isolated_world.name,
             "://",
             aux_json,

src/cdp/domains/page.zig

@@ -44,10 +44,7 @@ fn sendInspector(cmd: anytype, action: anytype) !void {
     const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
 
     // the result to return is handled directly by the inspector.
-    bc.session.callInspector(cmd.input.json);
-
-    // force running micro tasks after send input to the inspector.
-    cmd.cdp.browser.runMicrotasks();
+    bc.callInspector(cmd.input.json);
 }
 
 fn logInspector(cmd: anytype, action: anytype) !void {