add the mock transport and remove asClient* helpers (#268)

## Why

<!-- Describe what you are trying to accomplish with this pull request
-->

- `asClient*` style test helpers relied on emulating the logic in router
precisely and this can go out of date/drift as changes are made
- we noticed, for example, that the helpers dont abort the signal after
both sides of the handler exit for example

## What changed

- remove these test helpers in favour of a mock transport network

<!-- Describe the changes you made in this pull request or pointers for
the reviewer -->

## Versioning

- [ ] Breaking protocol change
- [x] Breaking ts/js API change

<!-- Kind reminder to add tests and updated documentation if needed -->

__tests__/bandwidth.bench.ts

@@ -1,9 +1,9 @@
 import { afterAll, assert, bench, describe } from 'vitest';
-import { getClientSendFn, waitForMessage } from '../util/testHelpers';
-import { TestServiceSchema } from './fixtures/services';
+import { getClientSendFn, waitForMessage } from '../testUtil';
+import { TestServiceSchema } from '../testUtil/fixtures/services';
 import { createServer } from '../router/server';
 import { createClient } from '../router/client';
-import { transports } from './fixtures/transports';
+import { transports } from '../testUtil/fixtures/transports';
 import { nanoid } from 'nanoid';
 
 let n = 0;
@@ -19,7 +19,7 @@ const dummyPayloadSmall = () => ({
 // give time for v8 to warm up
 const BENCH_DURATION = 10_000;
 describe('bandwidth', async () => {
-  for (const { name, setup } of transports) {
+  for (const { name, setup } of transports.filter((t) => t.name !== 'mock')) {
     const { getClientTransport, getServerTransport, cleanup } = await setup();
     afterAll(cleanup);
 
@@ -57,11 +57,12 @@ describe('bandwidth', async () => {
     );
 
     const { reqWritable, resReadable } = client.test.echo.stream({});
+    const resIter = resReadable[Symbol.asyncIterator]();
     bench(
       `${name} -- stream`,
       async () => {
         reqWritable.write({ msg: nanoid(), ignore: false });
-        const result = await resReadable[Symbol.asyncIterator]().next();
+        const result = await resIter.next();
         assert(result.value?.ok);
       },
       { time: BENCH_DURATION },

__tests__/cancellation.test.ts

@@ -9,15 +9,15 @@ import {
   createClient,
   createServer,
 } from '../router';
-import { testMatrix } from './fixtures/matrix';
+import { testMatrix } from '../testUtil/fixtures/matrix';
 import {
   cleanupTransports,
   createPostTestCleanups,
   testFinishesCleanly,
   waitFor,
-} from './fixtures/cleanup';
+} from '../testUtil/fixtures/cleanup';
 import { CANCEL_CODE, UNCAUGHT_ERROR_CODE } from '../router/errors';
-import { TestSetupHelpers } from './fixtures/transports';
+import { TestSetupHelpers } from '../testUtil/fixtures/transports';
 
 function makeMockHandler<T extends ValidProcType>(
   _type: T,

__tests__/cleanup.test.ts

@@ -5,12 +5,12 @@ import {
   isReadableDone,
   numberOfConnections,
   getClientSendFn,
-} from '../util/testHelpers';
+} from '../testUtil';
 import {
   SubscribableServiceSchema,
   TestServiceSchema,
   UploadableServiceSchema,
-} from './fixtures/services';
+} from '../testUtil/fixtures/services';
 import {
   Ok,
   Procedure,
@@ -26,9 +26,9 @@ import {
   createPostTestCleanups,
   testFinishesCleanly,
   waitFor,
-} from './fixtures/cleanup';
-import { testMatrix } from './fixtures/matrix';
-import { TestSetupHelpers } from './fixtures/transports';
+} from '../testUtil/fixtures/cleanup';
+import { testMatrix } from '../testUtil/fixtures/matrix';
+import { TestSetupHelpers } from '../testUtil/fixtures/transports';
 import { ControlFlags } from '../transport/message';
 import { Type } from '@sinclair/typebox';
 import { nanoid } from 'nanoid';

__tests__/context.test.ts

@@ -1,7 +1,10 @@
 import { beforeEach, describe, expect, test } from 'vitest';
-import { cleanupTransports, createPostTestCleanups } from './fixtures/cleanup';
-import { testMatrix } from './fixtures/matrix';
-import { TestSetupHelpers } from './fixtures/transports';
+import {
+  cleanupTransports,
+  createPostTestCleanups,
+} from '../testUtil/fixtures/cleanup';
+import { testMatrix } from '../testUtil/fixtures/matrix';
+import { TestSetupHelpers } from '../testUtil/fixtures/transports';
 import {
   Ok,
   Procedure,

__tests__/disconnects.test.ts

@@ -4,12 +4,12 @@ import {
   isReadableDone,
   numberOfConnections,
   readNextResult,
-} from '../util/testHelpers';
+} from '../testUtil';
 import {
   SubscribableServiceSchema,
   TestServiceSchema,
   UploadableServiceSchema,
-} from './fixtures/services';
+} from '../testUtil/fixtures/services';
 import {
   createClient,
   createServer,
@@ -20,10 +20,10 @@ import {
   cleanupTransports,
   testFinishesCleanly,
   waitFor,
-} from './fixtures/cleanup';
-import { testMatrix } from './fixtures/matrix';
-import { TestSetupHelpers } from './fixtures/transports';
-import { createPostTestCleanups } from './fixtures/cleanup';
+} from '../testUtil/fixtures/cleanup';
+import { testMatrix } from '../testUtil/fixtures/matrix';
+import { TestSetupHelpers } from '../testUtil/fixtures/transports';
+import { createPostTestCleanups } from '../testUtil/fixtures/cleanup';
 
 describe.each(testMatrix())(
   'procedures should handle unexpected disconnects ($transport.name transport, $codec.name codec)',

__tests__/e2e.test.ts

@@ -4,7 +4,7 @@ import {
   isReadableDone,
   numberOfConnections,
   readNextResult,
-} from '../util/testHelpers';
+} from '../testUtil';
 import { createServer } from '../router/server';
 import { createClient } from '../router/client';
 import {
@@ -17,15 +17,15 @@ import {
   UploadableServiceSchema,
   OrderingServiceSchema,
   NonObjectSchemas,
-} from './fixtures/services';
+} from '../testUtil/fixtures/services';
 import {
   advanceFakeTimersBySessionGrace,
   cleanupTransports,
   createPostTestCleanups,
   testFinishesCleanly,
   waitFor,
-} from './fixtures/cleanup';
-import { testMatrix } from './fixtures/matrix';
+} from '../testUtil/fixtures/cleanup';
+import { testMatrix } from '../testUtil/fixtures/matrix';
 import { Type } from '@sinclair/typebox';
 import {
   Procedure,
@@ -38,7 +38,7 @@ import {
   createClientHandshakeOptions,
   createServerHandshakeOptions,
 } from '../router/handshake';
-import { TestSetupHelpers } from './fixtures/transports';
+import { TestSetupHelpers } from '../testUtil/fixtures/transports';
 
 describe.each(testMatrix())(
   'client <-> server integration test ($transport.name transport, $codec.name codec)',
@@ -869,6 +869,7 @@ describe.each(testMatrix())(
         createClientHandshakeOptions(requestSchema, () => ({ data: 'foobar' })),
       );
       const serverTransport = getServerTransport(
+        'SERVER',
         createServerHandshakeOptions(requestSchema, (metadata) => {
           return {
             data: metadata.data,