Tweak wait_until option

Small tweaks to https://github.com/lightpanda-io/browser/pull/1896

Improve the wait ergonomics with an Option with default parameter. Revert
page pointer logic to original (don't think that change was necessary).

src/browser/Session.zig

@@ -319,11 +319,15 @@ fn findPageBy(page: *Page, comptime field: []const u8, id: u32) ?*Page {
     return null;
 }
 
-pub fn wait(self: *Session, wait_ms: u32, wait_until: lp.Config.WaitUntil) WaitResult {
+const WaitOpts = struct {
+    timeout_ms: u32 = 5000,
+    until: lp.Config.WaitUntil = .load,
+};
+
+pub fn wait(self: *Session, opts: WaitOpts) WaitResult {
+    var page = &(self.page orelse return .no_page);
     while (true) {
-        if (self.page == null) return .no_page;
+        const wait_result = self._wait(page, opts) catch |err| {
-        const page = &self.page.?;
-        const wait_result = self._wait(page, wait_ms, wait_until) catch |err| {
             switch (err) {
                 error.JsError => {}, // already logged (with hopefully more context)
                 else => log.err(.browser, "session wait", .{
@@ -340,15 +344,18 @@ pub fn wait(self: *Session, wait_ms: u32, wait_until: lp.Config.WaitUntil) WaitR
                     return .done;
                 }
                 self.processQueuedNavigation() catch return .done;
+                page = &self.page.?; // might have changed
             },
             else => |result| return result,
         }
     }
 }
 
-fn _wait(self: *Session, page: *Page, wait_ms: u32, wait_until: lp.Config.WaitUntil) !WaitResult {
+fn _wait(self: *Session, page: *Page, opts: WaitOpts) !WaitResult {
+    const wait_until = opts.until;
+
     var timer = try std.time.Timer.start();
-    var ms_remaining = wait_ms;
+    var ms_remaining = opts.timeout_ms;
 
     const browser = self.browser;
     var http_client = browser.http_client;
@@ -454,13 +461,13 @@ fn _wait(self: *Session, page: *Page, wait_ms: u32, wait_until: lp.Config.WaitUn
                         // Same as above, except we have a scheduled task,
                         // it just happens to be too far into the future
                         // compared to how long we were told to wait.
-                        if (!browser.hasBackgroundTasks()) {
+                        if (browser.hasBackgroundTasks()) {
-                            if (is_event_done) return .done;
-                        } else {
                             // _we_ have nothing to run, but v8 is working on
                             // background tasks. We'll wait for them.
                             browser.waitForBackgroundTasks();
                         }
+                        // We're still wait for our wait_until. Not sure for what
+                        // but let's keep waiting. Worst case, we'll timeout.
                         ms = 20;
                     }
 

src/cdp/cdp.zig

@@ -131,7 +131,7 @@ pub fn CDPT(comptime TypeProvider: type) type {
         // timeouts (or http events) which are ready to be processed.
         pub fn pageWait(self: *Self, ms: u32) Session.WaitResult {
             const session = &(self.browser.session orelse return .no_page);
-            return session.wait(ms, .load);
+            return session.wait(.{ .timeout_ms = ms });
         }
 
         // Called from above, in processMessage which handles client messages

src/cdp/domains/lp.zig

@@ -280,7 +280,7 @@ test "cdp.lp: action tools" {
     const page = try bc.session.createPage();
     const url = "http://localhost:9582/src/browser/tests/mcp_actions.html";
     try page.navigate(url, .{ .reason = .address_bar, .kind = .{ .push = null } });
-    _ = bc.session.wait(5000, .load);
+    _ = bc.session.wait(.{});
 
     // Test Click
     const btn = page.document.getElementById("btn", page).?.asNode();

src/cdp/testing.zig

@@ -136,7 +136,7 @@ const TestContext = struct {
                 0,
             );
             try page.navigate(full_url, .{});
-            _ = bc.session.wait(2000, .load);
+            _ = bc.session.wait(.{});
         }
         return bc;
     }

src/lightpanda.zig

@@ -108,7 +108,7 @@ pub fn fetch(app: *App, url: [:0]const u8, opts: FetchOpts) !void {
         .reason = .address_bar,
         .kind = .{ .push = null },
     });
-    _ = session.wait(opts.wait_ms, opts.wait_until);
+    _ = session.wait(.{ .timeout_ms = opts.wait_ms, .until = opts.wait_until });
 
     const writer = opts.writer orelse return;
     if (opts.dump_mode) |mode| {

src/main_legacy_test.zig

@@ -106,7 +106,7 @@ pub fn run(allocator: Allocator, file: []const u8, session: *lp.Session) !void {
     defer try_catch.deinit();
 
     try page.navigate(url, .{});
-    _ = session.wait(2000, .load);
+    _ = session.wait(.{});
 
     ls.local.eval("testing.assertOk()", "testing.assertOk()") catch |err| {
         const caught = try_catch.caughtOrError(allocator, err);

src/mcp/tools.zig

@@ -538,7 +538,7 @@ fn performGoto(server: *Server, url: [:0]const u8, id: std.json.Value) !void {
         return error.NavigationFailed;
     };
 
-    _ = server.session.wait(5000, .load);
+    _ = server.session.wait(.{});
 }
 
 const testing = @import("../testing.zig");
@@ -603,7 +603,7 @@ test "MCP - Actions: click, fill, scroll" {
     const page = try server.session.createPage();
     const url = "http://localhost:9582/src/browser/tests/mcp_actions.html";
     try page.navigate(url, .{ .reason = .address_bar, .kind = .{ .push = null } });
-    _ = server.session.wait(5000, .load);
+    _ = server.session.wait(.{});
 
     // Test Click
     const btn = page.document.getElementById("btn", page).?.asNode();

src/testing.zig

@@ -415,7 +415,7 @@ fn runWebApiTest(test_file: [:0]const u8) !void {
     defer try_catch.deinit();
 
     try page.navigate(url, .{});
-    _ = test_session.wait(2000, .load);
+    _ = test_session.wait(.{});
 
     test_browser.runMicrotasks();
 
@@ -439,7 +439,7 @@ pub fn pageTest(comptime test_file: []const u8) !*Page {
     );
 
     try page.navigate(url, .{});
-    _ = test_session.wait(2000, .load);
+    _ = test_session.wait(.{});
     return page;
 }