[protocol] Add more detailed CDPMessage types

This CL adds some basic message types for commands, responses, events
and errors.

The official source for these is
https://chromium.googlesource.com/deps/inspector_protocol/.

This CL was created mostly by using existing types and reverse-
engineering the C++ code.

[email protected]

Bug: 453469270
Change-Id: I5749ca31090f0069419fe455cbd976801008a2fe
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7079116
Reviewed-by: Alex Rudenko <[email protected]>
Commit-Queue: Simon Zünd <[email protected]>

Author: szuend

front_end/core/protocol_client/CDPConnection.ts

@@ -4,6 +4,55 @@
 
 import type {ProtocolMapping} from '../../generated/protocol-mapping.js';
 
+export type CommandParams<T extends keyof ProtocolMapping.Commands> = ProtocolMapping.Commands[T]['paramsType'][0];
+export type CommandResult<T extends keyof ProtocolMapping.Commands> = ProtocolMapping.Commands[T]['returnType'];
+export type EventParams<T extends keyof ProtocolMapping.Events> = ProtocolMapping.Events[T];
+
+export interface CDPBaseMessage {
+  sessionId?: string;
+}
+
+export interface CDPCommandRequest<T extends keyof ProtocolMapping.Commands> extends CDPBaseMessage {
+  id: number;
+  method: T;
+  params: CommandParams<T>;
+}
+
+export interface CDPCommandResponse<T extends keyof ProtocolMapping.Commands> extends CDPBaseMessage {
+  id: number;
+  result: CommandResult<T>;
+}
+
+export interface CDPEvent<T extends keyof ProtocolMapping.Events> extends CDPBaseMessage {
+  method: T;
+  params: EventParams<T>;
+}
+
+/**
+ * Keep this in sync with https://source.chromium.org/chromium/chromium/src/+/main:third_party/inspector_protocol/crdtp/dispatch.h.
+ */
+export const enum CDPErrorStatus {
+  PARSE_ERROR = -32700,
+  INVALID_REQUEST = -32600,
+  METHOD_NOT_FOUND = -32601,
+  INVALID_PARAMS = -32602,
+  INTERNAL_ERROR = -32603,
+  SERVER_ERROR = -32000,
+  SESSION_NOT_FOUND = SERVER_ERROR - 1,
+}
+
+export interface CDPError extends CDPBaseMessage {
+  id?: number;
+  error: {
+    code: CDPErrorStatus,
+    message: string,
+    data?: string,
+  };
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type CDPMessage = CDPCommandRequest<any>|CDPCommandResponse<any>|CDPEvent<any>|CDPError;
+
 /**
  * Allows the sending and receiving of CDP commands and the notification of CDP events to observers.
  *
@@ -12,9 +61,8 @@ import type {ProtocolMapping} from '../../generated/protocol-mapping.js';
  * would conflict with any other shared traffic.
  */
 export interface CDPConnection {
-  send<T extends keyof ProtocolMapping.Commands>(
-      method: T, params: ProtocolMapping.Commands[T]['paramsType'][0],
-      sessionId: string|undefined): Promise<ProtocolMapping.Commands[T]['returnType']|{getError(): string}>;
+  send<T extends keyof ProtocolMapping.Commands>(method: T, params: CommandParams<T>, sessionId: string|undefined):
+      Promise<CommandResult<T>|{getError(): string}>;
 
   observe(observer: CDPConnectionObserver): void;
   unobserve(observer: CDPConnectionObserver): void;
@@ -34,6 +82,6 @@ export interface DebuggableCDPConnection extends CDPConnection {
 }
 
 export interface RawMessageObserver {
-  onMessageReceived(message: unknown): void;
-  onMessageSent(message: unknown): void;
+  onMessageReceived(message: CDPMessage): void;
+  onMessageSent(message: CDPMessage): void;
 }

front_end/core/protocol_client/protocol_client.ts

@@ -2,11 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import * as CDPConnection from './CDPConnection.js';
 import * as ConnectionTransport from './ConnectionTransport.js';
 import * as InspectorBackend from './InspectorBackend.js';
 import * as NodeURL from './NodeURL.js';
 
 export {
+  CDPConnection,
   ConnectionTransport,
   InspectorBackend,
   NodeURL,

front_end/testing/MockConnection.ts

@@ -12,12 +12,13 @@ import {cleanTestDOM} from './DOMHooks.js';
 import {deinitializeGlobalVars, initializeGlobalVars} from './EnvironmentHelpers.js';
 import {setMockResourceTree} from './ResourceTreeHelpers.js';
 
-export type ProtocolCommand = keyof ProtocolMapping.Commands;
-export type ProtocolCommandParams<C extends ProtocolCommand> = ProtocolMapping.Commands[C]['paramsType'];
-export type ProtocolResponse<C extends ProtocolCommand> = ProtocolMapping.Commands[C]['returnType'];
-export type ProtocolCommandHandler<C extends ProtocolCommand> = (...params: ProtocolCommandParams<C>) =>
-    Omit<ProtocolResponse<C>, 'getError'>|{getError(): string}|
-    PromiseLike<Omit<ProtocolResponse<C>, 'getError'>|{getError(): string}>;
+type ProtocolCommand = keyof ProtocolMapping.Commands;
+type CommandParams<C extends keyof ProtocolMapping.Commands> = ProtocolClient.CDPConnection.CommandParams<C>;
+type CommandResult<C extends keyof ProtocolMapping.Commands> = ProtocolClient.CDPConnection.CommandResult<C>;
+
+export type ProtocolCommandHandler<C extends keyof ProtocolMapping.Commands> = (param: CommandParams<C>) =>
+    Omit<CommandResult<C>, 'getError'>|{getError(): string}|
+    PromiseLike<Omit<CommandResult<C>, 'getError'>|{getError(): string}>;
 export type MessageCallback = (result: string|Object) => void;
 interface Message {
   id: number;