feat: support Accept header in @helia/verified-fetch
#438
Conversation
Let users get raw data back from CIDs that would otherwise trigger
decoding as JSON or CBOR etc by specifying an `Accept` header.
```typescript
const res = await verifiedFetch(cid, {
headers: {
accept: 'application/octet-stream'
}
})
console.info(res.headers.get('accept')) // application/octet-stream
```
Make sure the content-type matches the accept header:
```typescript
const res = await verifiedFetch(cid, {
headers: {
accept: 'application/vnd.ipld.raw'
}
})
console.info(res.headers.get('accept')) // application/vnd.ipld.raw
```
Support multiple values, match the first one:
```typescript
const res = await verifiedFetch(cid, {
headers: {
accept: 'application/vnd.ipld.raw, application/octet-stream, */*'
}
})
console.info(res.headers.get('accept')) // application/vnd.ipld.raw
```
If they specify an Accept header we can't honor, return a [406](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/406):
```typescript
const res = await verifiedFetch(cid, {
headers: {
accept: 'application/what-even-is-this'
}
})
console.info(res.status) // 406
```
|
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||
| const resp = await verifiedFetch.fetch(cid, { | ||
| headers: { | ||
| accept: 'application/what-even-is-this, */*' |
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nit: we were not testing with ;q=, below adds what Firefox sends, should be enough as a regression test:
| accept: 'application/what-even-is-this, */*' | |
| accept: 'application/what-even-is-this,text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8' |
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Looks good.
Nice to have the challenge I brought up addressed by this. 💯
|
@lidel @2color please take another look - I've added a lot more tests, support for wildcards and q-factor and also the IPLD serialized type conversions from https://specs.ipfs.tech/http-gateways/path-gateway/#accept-request-header |
| @@ -0,0 +1,117 @@ | |||
| import { code as dagCborCode } from '@ipld/dag-cbor' | |||
| import { code as dagJsonCode } from '@ipld/dag-json' | |||
| import type { RequestFormatShorthand } from '../types.js' | |||
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We could move requestFormatShorthand in here as well, or merge with FORMATS
| expect(output).to.deep.equal(obj) | ||
| }) | ||
|
|
||
| it('should transform DAG-JSON to DAG-CBOR', async () => { |
| function notSupportedResponse (body?: BodyInit | null): Response { | ||
| return new Response(body, { | ||
| const response = new Response(body, { | ||
| status: 501, | ||
| statusText: 'Not Implemented' | ||
| }) | ||
| response.headers.set('X-Content-Type-Options', 'nosniff') // see https://specs.ipfs.tech/http-gateways/path-gateway/#x-content-type-options-response-header | ||
| return response | ||
| } | ||
|
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||
| function notAcceptableResponse (body?: BodyInit | null): Response { | ||
| return new Response(body, { | ||
| status: 406, | ||
| statusText: '406 Not Acceptable' | ||
| }) | ||
| } |
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we might want to move these into their own file soon. this file is getting excessive.
| return response | ||
| } | ||
|
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||
| private async handleDagCbor ({ cid, path, options }: FetchHandlerFunctionArg): Promise<Response> { | ||
| private async handleDagCbor ({ cid, path, accept, options }: FetchHandlerFunctionArg): Promise<Response> { |
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we might need to break these functions out at some point as well.
| if (ipfsRoots != null) { | ||
| response.headers.set('X-Ipfs-Roots', ipfsRoots.map(cid => cid.toV1().toString()).join(',')) // https://specs.ipfs.tech/http-gateways/path-gateway/#x-ipfs-roots-response-header | ||
| } |
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we will likely need to pull this out of handleDagPb so we can set roots for others as well
Co-authored-by: Russell Dempsey <1173416+SgtPooki@users.noreply.github.com>
Co-authored-by: Russell Dempsey <1173416+SgtPooki@users.noreply.github.com>
| } | ||
| }) | ||
| expect(resp.status).to.equal(200) | ||
| expect(resp.headers.get('content-type')).to.equal('application/json') |
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This is pretty counter intuitive, but my understanding is that the order matters and that when processing */* the default mime-type is returned, which according to the map is application/json
Let users get raw data back from CIDs that would otherwise trigger decoding as JSON or CBOR etc by specifying an
Acceptheader.Make sure the content-type matches the accept header:
Support multiple values, match the first one:
If they specify an Accept header we can't honour, one that doesn't match the eventual content type, or one returned by the content type parser return a 406:
Change checklist