Handle sessionId in result

Signed-off-by: Francis Bouvier <francis@lightpanda.io>

src/cdp/browser.zig

@@ -52,7 +52,7 @@ fn browserGetVersion(
         .userAgent = UserAgent,
         .jsVersion = JsVersion,
     };
-    return result(alloc, id, Res, res);
+    return result(alloc, id, Res, res, null);
 }
 
 fn browserSetDownloadBehavior(
@@ -69,5 +69,5 @@ fn browserSetDownloadBehavior(
     };
     const params = try getParams(alloc, Params, scanner);
     std.log.debug("params {any}", .{params});
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }

src/cdp/cdp.zig

@@ -78,8 +78,6 @@ fn checkKey(key: []const u8, token: []const u8) !void {
     if (!std.mem.eql(u8, key, token)) return error.WrongToken;
 }
 
-const resultNull = "{{\"id\": {d}, \"result\": {{}}}}";
-
 // caller owns the slice returned
 pub fn stringify(alloc: std.mem.Allocator, res: anytype) ![]const u8 {
     var out = std.ArrayList(u8).init(alloc);
@@ -94,20 +92,31 @@ pub fn stringify(alloc: std.mem.Allocator, res: anytype) ![]const u8 {
     return ret;
 }
 
+const resultNull = "{{\"id\": {d}, \"result\": {{}}}}";
+const resultNullSession = "{{\"id\": {d}, \"result\": {{}}, \"sessionId\": \"{s}\"}}";
+
 // caller owns the slice returned
 pub fn result(
     alloc: std.mem.Allocator,
     id: u64,
     comptime T: ?type,
     res: anytype,
+    sessionID: ?[]const u8,
 ) ![]const u8 {
-    if (T == null) return try std.fmt.allocPrint(alloc, resultNull, .{id});
+    if (T == null) {
+        // No need to stringify a custom JSON msg, just use string templates
+        if (sessionID) |sID| {
+            return try std.fmt.allocPrint(alloc, resultNullSession, .{ id, sID });
+        }
+        return try std.fmt.allocPrint(alloc, resultNull, .{id});
+    }
 
     const Resp = struct {
         id: u64,
         result: T.?,
+        sessionId: ?[]const u8,
     };
-    const resp = Resp{ .id = id, .result = res };
+    const resp = Resp{ .id = id, .result = res, .sessionId = sessionID };
 
     return stringify(alloc, resp);
 }
@@ -125,32 +134,32 @@ pub fn getParams(
     return std.json.innerParse(T, alloc, scanner, options);
 }
 
-pub fn getSessionID(
-    alloc: std.mem.Allocator,
-    scanner: *std.json.Scanner,
-) ![]const u8 {
-    var n = (try scanner.next()).string;
+pub fn getSessionID(scanner: *std.json.Scanner) !?[]const u8 {
+
+    // if next token is the end of the object, there is no "sessionId"
+    const t = try scanner.next();
+    if (t == .object_end) return null;
+
+    var n = t.string;
+
+    // if next token is "params" ignore them
+    // NOTE: will panic if it's not an empty "params" object
+    // TODO: maybe we should return a custom error here
     if (std.mem.eql(u8, n, "params")) {
         // ignore empty params
         _ = (try scanner.next()).object_begin;
         _ = (try scanner.next()).object_end;
         n = (try scanner.next()).string;
     }
-    try checkKey("sessionId", n);
-    const options = std.json.ParseOptions{
-        .max_value_len = scanner.input.len,
-        .allocate = .alloc_if_needed,
-    };
-    return std.json.innerParse([]const u8, alloc, scanner, options);
+
+    // if next token is not "sessionId" there is no "sessionId"
+    if (!std.mem.eql(u8, n, "sessionId")) return null;
+
+    // parse "sessionId"
+    return (try scanner.next()).string;
 }
 
 // Common
 // ------
 
 pub const SessionID = "9559320D92474062597D9875C664CAC0";
-
-pub const SessionIDResp = struct {
-    id: u64,
-    result: struct {} = .{},
-    sessionId: []const u8,
-};

src/cdp/emulation.zig

@@ -32,7 +32,7 @@ fn setEmulatedMedia(
     _: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }
 
 fn setFocusEmulationEnabled(
@@ -41,5 +41,5 @@ fn setFocusEmulationEnabled(
     _: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }

src/cdp/log.zig

@@ -31,8 +31,6 @@ fn enable(
     scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return stringify(alloc, cdp.SessionIDResp{
-        .id = id,
-        .sessionId = try cdp.getSessionID(alloc, scanner),
-    });
+    const sessionID = try cdp.getSessionID(scanner);
+    return result(alloc, id, null, null, sessionID);
 }

src/cdp/network.zig

@@ -31,8 +31,6 @@ fn enable(
     scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return stringify(alloc, cdp.SessionIDResp{
-        .id = id,
-        .sessionId = try cdp.getSessionID(alloc, scanner),
-    });
+    const sessionID = try cdp.getSessionID(scanner);
+    return result(alloc, id, null, null, sessionID);
 }

src/cdp/page.zig

@@ -37,10 +37,8 @@ fn enable(
     scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return stringify(alloc, cdp.SessionIDResp{
-        .id = id,
-        .sessionId = try cdp.getSessionID(alloc, scanner),
-    });
+    const sessionID = try cdp.getSessionID(scanner);
+    return result(alloc, id, null, null, sessionID);
 }
 
 fn getFrameTree(
@@ -50,17 +48,26 @@ fn getFrameTree(
     _: *Ctx,
 ) ![]const u8 {
     // TODO: dummy
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }
 
 fn setLifecycleEventsEnabled(
     alloc: std.mem.Allocator,
     id: u64,
-    _: *std.json.Scanner,
+    scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
+
+    // input
+    const Params = struct {
+        enabled: bool,
+    };
+    _ = try getParams(alloc, Params, scanner);
+    const sessionID = try cdp.getSessionID(scanner);
+
+    // output
     // TODO: dummy
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, sessionID);
 }
 
 fn addScriptToEvaluateOnNewDocument(
@@ -69,20 +76,18 @@ fn addScriptToEvaluateOnNewDocument(
     scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
+
+    // input
     const Params = struct {
         source: []const u8,
         worldName: ?[]const u8 = null,
     };
     _ = try getParams(alloc, Params, scanner);
+    const sessionID = try cdp.getSessionID(scanner);
+
+    // output
     const Res = struct {
-        id: u64,
-        result: struct {
         identifier: []const u8 = "1",
-        } = .{},
-        sessionId: []const u8,
     };
-    return stringify(alloc, Res{
-        .id = id,
-        .sessionId = try cdp.getSessionID(alloc, scanner),
-    });
+    return result(alloc, id, Res, Res{}, sessionID);
 }

src/cdp/runtime.zig

@@ -33,10 +33,8 @@ fn enable(
     scanner: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return stringify(alloc, cdp.SessionIDResp{
-        .id = id,
-        .sessionId = try cdp.getSessionID(alloc, scanner),
-    });
+    const sessionID = try cdp.getSessionID(scanner);
+    return result(alloc, id, null, null, sessionID);
 }
 
 fn runIfWaitingForDebugger(
@@ -45,5 +43,5 @@ fn runIfWaitingForDebugger(
     _: *std.json.Scanner,
     _: *Ctx,
 ) ![]const u8 {
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }

src/cdp/target.zig

@@ -2,9 +2,10 @@ const std = @import("std");
 
 const server = @import("../server.zig");
 const Ctx = server.Cmd;
-const result = @import("cdp.zig").result;
-const getParams = @import("cdp.zig").getParams;
-const stringify = @import("cdp.zig").stringify;
+const cdp = @import("cdp.zig");
+const result = cdp.result;
+const getParams = cdp.getParams;
+const stringify = cdp.stringify;
 
 const TargetMethods = enum {
     setAutoAttach,
@@ -63,7 +64,7 @@ fn tagetSetAutoAttach(
     const attached = try stringify(alloc, AttachToTarget{});
     try server.sendSync(ctx, attached);
 
-    return result(alloc, id, null, null);
+    return result(alloc, id, null, null, null);
 }
 
 fn tagetGetTargetInfo(