feat(typescript): support bytes responses

[dsinghvi]

Description

This PR supports bytes responses in the TypeScript SDK. A bytes response is returned as an ArrayBuffer.

Changes Made

• Upgrade to IR v54
• Handle HttpResponseBody.Bytes
• Introduce a new endpoint to the bytes Fern Definition for bytes download (affects seed)
• Release a new CLI version that will run appropriate IR migrations for v55 -> v54

Testing

• Unit tests added/updated
• Manual testing completed

[dsinghvi]

Critical change

[Swimburger]

The generated SDKs should be flexible enough to retrieve the bytes as an array buffer (fully in-memory) or using a stream where the whole file isn't in memory.

Instead of returning ArrayBuffer, maybe we can return a type where the user can decide to get the buffer or stream.

export interface FooBarResponse {
  buffer: () => Promise<ArrayBuffer>;
  steam: () => Promise<ReadableStream>;
}

At AssemblyAI we did this:

const response = await fetch(redacted_audio_url);
if (!response.ok) {
  throw new Error(`Failed to fetch redacted audio: ${response.statusText}`);
}
return {
  arrayBuffer: response.arrayBuffer.bind(response),
  blob: response.blob.bind(response),
  body: response.body,
  bodyUsed: response.bodyUsed,
};

[remorses]

In that case Response is the best option, it can be streamed, turned into a buffer, blob, etc

[github-actions]

🌿 Preview your docs: https://fern-preview-538aa1ff-0b97-4a61-ab46-9c8b19560a43.docs.buildwithfern.com/learn

[amckinney]

Looks great 👏

[Swimburger]

"Upgraces" typo

[Swimburger]

"ugprade" typo

[Swimburger]

The generated SDKs should be flexible enough to retrieve the bytes as an array buffer (fully in-memory) or using a stream where the whole file isn't in memory.

Instead of returning ArrayBuffer, maybe we can return a type where the user can decide to get the buffer or stream.

export interface FooBarResponse {
  buffer: () => Promise<ArrayBuffer>;
  steam: () => Promise<ReadableStream>;
}

At AssemblyAI we did this:

const response = await fetch(redacted_audio_url);
if (!response.ok) {
  throw new Error(`Failed to fetch redacted audio: ${response.statusText}`);
}
return {
  arrayBuffer: response.arrayBuffer.bind(response),
  blob: response.blob.bind(response),
  body: response.body,
  bodyUsed: response.bodyUsed,
};