support null params to CDP DOM.getDocument

Author: karlseguin

src/cdp/domains/dom.zig

@@ -60,18 +60,19 @@ pub fn processMessage(cmd: anytype) !void {
 
 // https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-getDocument
 fn getDocument(cmd: anytype) !void {
-    const params = (try cmd.params(struct {
+    const Params = struct {
         // CDP documentation implies that 0 isn't valid, but it _does_ work in Chrome
-        depth: ?i32 = null,
-        pierce: ?bool = null,
-    })) orelse return error.InvalidParams;
+        depth: i32 = 3,
+        pierce: bool = false,
+    };
+    const params = try cmd.params(Params) orelse Params{};
 
     const bc = cmd.browser_context orelse return error.BrowserContextNotLoaded;
     const page = bc.session.currentPage() orelse return error.PageNotLoaded;
     const doc = parser.documentHTMLToDocument(page.window.document);
 
     const node = try bc.node_registry.register(parser.documentToNode(doc));
-    return cmd.sendResult(.{ .root = bc.nodeWriter(node, .{ .depth = params.depth orelse 3 }) }, .{});
+    return cmd.sendResult(.{ .root = bc.nodeWriter(node, .{ .depth = params.depth }) }, .{});
 }
 
 // https://chromedevtools.github.io/devtools-protocol/tot/DOM/#method-performSearch
@@ -611,7 +612,6 @@ test "cdp.dom: getBoxModel" {
     try ctx.processMessage(.{ // Hacky way to make sure nodeId 0 exists in the registry
         .id = 3,
         .method = "DOM.getDocument",
-        .params = .{ .depth = 3 },
     });
 
     try ctx.processMessage(.{