Use node-fetch on javascript SDK

We realized that the sdk is run on client's server and we can't control
the nodejs version or if the have `fetch` polyfill. Also one user saw
our sdk failing with TLSSocket.onSocketEnd TypeError terminated
other.side closed. The stack trace we saw was pointing to undinci
nodejs/undici#583
Which looks is the nodejs fetch implementatin. So we try to use
node-fetch to see if this mitigates the error

packages/sdks/typescript/package.json

@@ -27,6 +27,7 @@
   "dependencies": {
     "@t3-oss/env-core": "^0.10.1",
     "eventsource-parser": "^2.0.1",
+    "node-fetch": "3.3.2",
     "zod": "^3.23.8"
   },
   "devDependencies": {
@@ -38,6 +39,8 @@
     "@rollup/plugin-replace": "^6.0.1",
     "@rollup/plugin-typescript": "^11.1.6",
     "@types/eventsource": "^1.1.15",
+    "@types/node": "^22.7.5",
+    "@types/node-fetch": "^2.6.11",
     "msw": "^2.3.5",
     "rollup": "^4.21.1",
     "rollup-plugin-dts": "^6.1.1",

packages/sdks/typescript/rollup.config.mjs

@@ -19,7 +19,9 @@ const aliasEntries = {
 const EXTERNALS = [
   '@t3-oss/env-core',
   'zod',
+  // This fix some circular dependencies from core. Not really needed in prod
   'flydrive/types',
+  'node-fetch',
   'stream',
   'eventsource-parser/stream',
 ]

packages/sdks/typescript/src/index.ts

@@ -1,3 +1,5 @@
+import { Readable } from 'stream'
+
 import type { Config, Message } from '@latitude-data/compiler'
 import type {
   ChainCallResponseDto,
@@ -7,9 +9,11 @@ import type {
 } from '@latitude-data/core/browser'
 import env from '$sdk/env'
 import { GatewayApiConfig, RouteResolver } from '$sdk/utils'
+import { nodeFetchResponseToReadableStream } from '$sdk/utils/nodeFetchResponseToReadableStream'
 import { BodyParams, HandlerType, UrlParams } from '$sdk/utils/types'
 import { ParsedEvent, ReconnectInterval } from 'eventsource-parser'
 import { EventSourceParserStream } from 'eventsource-parser/stream'
+import nodeFetch from 'node-fetch'
 
 export type StreamChainResponse = {
   conversation: Message[]
@@ -153,7 +157,7 @@ export class Latitude {
     versionUuid = versionUuid ?? this.versionUuid
 
     try {
-      const response = await this.request({
+      const response = await this.nodeFetchRequest({
         method: 'POST',
         handler: HandlerType.RunDocument,
         params: { projectId, versionUuid },
@@ -166,7 +170,7 @@ export class Latitude {
       }
 
       return this.handleStream({
-        stream: response.body!,
+        body: response.body! as Readable,
         onEvent,
         onFinished,
         onError,
@@ -182,33 +186,34 @@ export class Latitude {
     messages: Message[],
     { onEvent, onFinished, onError }: StreamResponseCallbacks = {},
   ) {
-    const response = await this.request({
+    const response = await this.nodeFetchRequest({
       method: 'POST',
       handler: HandlerType.Chat,
       params: { conversationUuid: uuid },
       body: { messages },
     })
     return this.handleStream({
-      stream: response.body!,
+      body: response.body! as Readable,
       onEvent,
       onFinished,
       onError,
     })
   }
 
   private async handleStream({
-    stream,
+    body,
     onEvent,
     onFinished,
     onError,
   }: StreamResponseCallbacks & {
-    stream: ReadableStream
+    body: Readable
   }) {
     let conversation: Message[] = []
     let uuid: string | undefined
     let chainResponse: ChainCallResponseDto | undefined
 
     const parser = new EventSourceParserStream()
+    const stream = nodeFetchResponseToReadableStream(body)
     const eventStream = stream
       .pipeThrough(new TextDecoderStream())
       .pipeThrough(parser)
@@ -286,6 +291,27 @@ export class Latitude {
     })
   }
 
+  private async nodeFetchRequest<H extends HandlerType>({
+    method,
+    handler,
+    params,
+    body,
+  }: {
+    handler: H
+    params?: UrlParams<H>
+    method: 'POST' | 'GET' | 'PUT' | 'DELETE'
+    body?: BodyParams<H>
+  }) {
+    return nodeFetch(this.routeResolver.resolve({ handler, params }), {
+      method,
+      headers: this.authHeader,
+      body:
+        method === 'POST'
+          ? this.bodyToString({ ...body, __internal: { source: this.source } })
+          : undefined,
+    })
+  }
+
   private parseJSON(line: string) {
     try {
       return JSON.parse(line) as ChainEventDto

packages/sdks/typescript/src/utils/nodeFetchResponseToReadableStream.ts

@@ -0,0 +1,19 @@
+import { Readable } from 'stream'
+
+export function nodeFetchResponseToReadableStream(nodeStream: Readable) {
+  return new ReadableStream({
+    start(controller) {
+      nodeStream.on('data', (chunk: Buffer) => {
+        controller.enqueue(chunk)
+      })
+
+      nodeStream.on('end', () => {
+        controller.close()
+      })
+
+      nodeStream.on('error', (err) => {
+        controller.error(err)
+      })
+    },
+  })
+}