@spoosh/plugin-transform

Transform response data with full type inference.

Documentation · Requirements: TypeScript >= 5.0 · Peer Dependencies: @spoosh/core

Installation

``bash
npm install @spoosh/plugin-transform
`

Usage

$3

Response transforms produce a separate transformedData field in meta while preserving the original data:

`typescript
import { Spoosh } from "@spoosh/core";
import { transformPlugin } from "@spoosh/plugin-transform";

const client = new Spoosh("/api").use([transformPlugin()]);

const { data, meta } = useRead((api) => api("posts").GET(), {
transform: (posts) => ({
count: posts.length,
hasMore: posts.length >= 10,
ids: posts.map((p) => p.id),
}),
});

// data = Post[] (original response, preserved)
// meta.transformedData = { count: number, hasMore: boolean, ids: number[] } | undefined
`

$3

Transform functions support async operations:

`typescript
const { data, meta } = useRead((api) => api("posts").GET(), {
transform: async (posts) => {
const enriched = await enrichPostsWithMetadata(posts);
return {
count: enriched.length,
titles: enriched.map((p) => p.title),
};
},
});
`

Features

- ✅ Full type inference for transforms
- ✅ Async transform functions supported
- ✅ Per-request transforms (no global config needed)
- ✅ Return undefined to remove data entirely

TypeScript Limitation (useWrite)

Due to TypeScript limitations with dynamic trigger options, meta.transformedData is typed as never in useWrite hook results. Use type assertion:

`typescript
type TransformedPost = {
success: boolean;
postId: number;
};

const { meta } = useWrite((api) => api("posts").POST);

// Type assertion required
const typed = meta.transformedData as TransformedPost | undefined;
`

This limitation does not affect useRead or useInfiniteRead`, where options are passed at hook creation time.