wip tree-shakable http

TODO test and check what happens if you don't provide one

note: the additionalHTTPRequestImplementations is copied from
additionalTransportImplementations. but I think the approach doesn't
need to be the same, because we have one connection manager which had to
make use of available transports, but for HTTP we have separate classes
for web and node

perhaps we'd be best off adding some sort of bundledImplementations
thing on the web HTTP class, such that it can be used in tests directly?

scripts/moduleReport.js

@@ -9,6 +9,8 @@ const moduleNames = [
   'XHRPolling',
   'XHRStreaming',
   'WebSocketTransport',
+  'XHRRequest',
+  'FetchRequest',
 ];
 
 // List of all free-standing functions exported by the library along with the

src/common/lib/client/baseclient.ts

@@ -8,7 +8,7 @@ import { StandardCallback } from '../../types/utils';
 import { IHttp, RequestParams } from '../../types/http';
 import ClientOptions, { NormalisedClientOptions } from '../../types/ClientOptions';
 
-import Platform from '../../platform';
+import Platform, { HTTPRequestImplementations, HTTPRequestMechanismNames } from '../../platform';
 import { ModulesMap } from './modulesmap';
 import { Rest } from './rest';
 import { IUntypedCryptoStatic } from 'common/types/ICryptoStatic';
@@ -31,8 +31,12 @@ class BaseClient {
   private readonly _rest: Rest | null;
   readonly _Crypto: IUntypedCryptoStatic | null;
   readonly _MsgPack: MsgPack | null;
+  // Extra HTTP request implementations available to this client, in addition to those directly accessed in our HTTP code
+  readonly _additionalHTTPRequestImplementations: HTTPRequestImplementations;
 
   constructor(options: ClientOptions | string, modules: ModulesMap) {
+    this._additionalHTTPRequestImplementations = BaseClient.httpRequestImplementationsFromModules(modules);
+
     if (!options) {
       const msg = 'no options provided';
       Logger.logAction(Logger.LOG_ERROR, 'BaseClient()', msg);
@@ -85,6 +89,20 @@ class BaseClient {
     this._Crypto = modules.Crypto ?? null;
   }
 
+  private static httpRequestImplementationsFromModules(modules: ModulesMap) {
+    const implementations: HTTPRequestImplementations = {};
+
+    if (modules.XHRRequest) {
+      implementations[HTTPRequestMechanismNames.XHR] = modules.XHRRequest;
+    }
+
+    if (modules.FetchRequest) {
+      implementations[HTTPRequestMechanismNames.Fetch] = modules.FetchRequest;
+    }
+
+    return implementations;
+  }
+
   private get rest(): Rest {
     if (!this._rest) {
       throwMissingModuleError('Crypto');

src/common/lib/client/modulesmap.ts

@@ -3,6 +3,7 @@ import { IUntypedCryptoStatic } from '../../types/ICryptoStatic';
 import { MsgPack } from 'common/types/msgpack';
 import RealtimePresence from './realtimepresence';
 import { TransportInitialiser } from '../transport/connectionmanager';
+import { IHttp } from 'common/types/http';
 
 export interface ModulesMap {
   Rest?: typeof Rest;
@@ -12,6 +13,8 @@ export interface ModulesMap {
   WebSocketTransport?: TransportInitialiser;
   XHRPolling?: TransportInitialiser;
   XHRStreaming?: TransportInitialiser;
+  XHRRequest?: IHttp;
+  FetchRequest?: IHttp;
 }
 
 export const allCommonModules: ModulesMap = { Rest };

src/common/platform.ts

@@ -1,5 +1,5 @@
 import { IPlatformConfig } from './types/IPlatformConfig';
-import { IHttpStatic } from './types/http';
+import { IHttp, IHttpStatic } from './types/http';
 import { TransportInitialiser } from './lib/transport/connectionmanager';
 import IDefaults from './types/IDefaults';
 import IWebStorage from './types/IWebStorage';
@@ -15,6 +15,15 @@ type ToBufferOutput = WebBufferUtils.ToBufferOutput | NodeBufferUtils.ToBufferOu
 
 export type TransportImplementations = Partial<Record<TransportName, TransportInitialiser>>;
 
+export namespace HTTPRequestMechanismNames {
+  export const XHR = 'xhr' as const;
+  export const Fetch = 'fetch' as const;
+}
+
+export type HTTPRequestMechanismName = typeof HTTPRequestMechanismNames.XHR | typeof HTTPRequestMechanismNames.Fetch;
+
+export type HTTPRequestImplementations = Partial<Record<HTTPRequestMechanismName, IHttp>>;
+
 export default class Platform {
   static Config: IPlatformConfig;
   /*

src/platform/web/modules.ts

@@ -44,5 +44,6 @@ export * from './modules/presencemessage';
 export * from './modules/msgpack';
 export * from './modules/realtimepresence';
 export * from './modules/transports';
+export * from './modules/http';
 export { Rest } from '../../common/lib/client/rest';
 export { BaseRest, BaseRealtime };

src/platform/web/modules/http.ts

@@ -0,0 +1,2 @@
+export { default as XHRRequest } from '../lib/transport/xhrrequest';
+export { default as FetchRequest } from '../lib/transport/fetchrequest';