Node core function for reading streams not recognized in React Native app made with AWS SDK

With some trivial modifications (including a conversion to TypeScript), I copied and pasted the JS code from this Amazon S3 Node.js example into a React Native app that I'm developing with Expo and USB debugging on Android. I want my program to read from a JSON file in one of my Amazon S3 buckets.

import 'react-native-url-polyfill/auto'import 'react-native-get-random-values'import { Readable } from 'node:stream'import { CognitoIdentityClient } from '@aws-sdk/client-cognito-identity'import { fromCognitoIdentityPool } from '@aws-sdk/credential-provider-cognito-identity'// Create service client module using ES6 syntax.import {    S3Client,    GetObjectCommand,    GetObjectOutput} from '@aws-sdk/client-s3'// Set the AWS Region.const region = 'us-east-1'// Create an Amazon S3 service client object.const client = new S3Client({    region,    credentials: fromCognitoIdentityPool({        client: new CognitoIdentityClient({ region }),        identityPoolId: 'us-east-1:xxxxxx-xxx-4103-9936-b52exxxxfd6'    })})export const bucketParams = {    Bucket: 'bucket-name',    Key: 'filename.json'}export const run = async (): Promise<string> => {    // Create a helper function to convert a ReadableStream to a string.    const streamToString = (stream: Readable): Promise<string> =>        new Promise((resolve, reject) => {            const chunks: Uint8Array[] = []            stream.on('data', (chunk: Uint8Array): void => {chunks.push(chunk)})            stream.on('error', reject)            stream.on('end', (): void => resolve(Buffer.concat(chunks).toString('utf8')))        })    // Get the object from the Amazon S3 bucket. It is returned as a ReadableStream.    const data: GetObjectOutput = await client.send(new GetObjectCommand(bucketParams))    // Convert the ReadableStream to a string.    const bodyContents: string = await streamToString(data.Body as Readable)    return bodyContents}

I've already confirmed (I think) that the const variable data is successfully assigned a proper value (an object, at least) before its property Body is passed as an argument to streamToString. In light of this, the line const data: GetObjectOutput = await client.send(new GetObjectCommand(bucketParams)) seems to do its job—assign to data a JavaScript object of type GetObjectOutput with a property Body of the union type Readable | ReadableStream<any> | Blob | undefined.

In order to test the initialization of bodyContents, I wrote and called an anonymous function, as follows:

(async () => alert( await run() ))()

When I ran this test, the value of bodyContents was not printed as expected. Instead, I got an error:

[Unhandled promise rejection: TypeError: stream.on is not a function. (In 'stream.on('data', function (chunk) {]
at Contents.tsx:154:16 in Promise$argument_0
at Contents.tsx:152:12 in streamToString
at Contents.tsx:163:57 in run

To see what might be causing this error, I command-clicked, within VS Code, the first call to the function on inside the initialization of streamToString, with the event 'data' as its first argument. I was thereby directed to the corresponding declaration—along with 7 overloads—of on, which is a method inside the class Readable. This class is defined in the file stream.d.ts from the Node core library (node_modules/@types/node/stream.d.ts). Here is the corresponding declaration of on, written in TypeScript:

on(event: 'data', listener: (chunk: any) => void): this;

Considering that my first call to stream.on conforms to this declaration, I don't understand why stream.on is not recognized as a function. I did import the class Readable which contains the method's declaration, after all. To see that the function call conforms to the declaration, note that stream is a Readable object, and I pass in arguments of the forms 'data' (that is, the exact string 'data') and (chunk: any) => void, respectively. Uint8Array falls under any, of course, as does any type.

I realize that the implementations of on may, for all I know, be missing from my project. I've yet to track down a single implementation worthy of the name in my project, despite my diligent command-clicking in VS Code. I'm taking it on faith that I don't have to implement the function myself, since there is no mention of that in the AWS docs. But if I do have to, that means I need to acquaint myself with the algorithm that this overload of on is meant to implement. All I know is that it's supposed to read streams of data.

How do I get this bug out of my hair?