feat: customize ipns dnsResolvers

packages/verified-fetch/src/verified-fetch.ts

@@ -1,4 +1,4 @@
-import { ipns as heliaIpns, type IPNS } from '@helia/ipns'
+import { ipns as heliaIpns, type DNSResolver, type IPNS } from '@helia/ipns'
 import { dnsJsonOverHttps } from '@helia/ipns/dns-resolvers'
 import { unixfs as heliaUnixFs, type UnixFS as HeliaUnixFs, type UnixFSStats } from '@helia/unixfs'
 import { code as dagCborCode } from '@ipld/dag-cbor'
@@ -32,6 +32,7 @@ interface VerifiedFetchComponents {
  */
 interface VerifiedFetchInit {
   contentTypeParser?: ContentTypeParser
+  dnsResolvers?: DNSResolver[]
 }
 
 interface FetchHandlerFunctionArg {
@@ -86,7 +87,7 @@ export class VerifiedFetch {
     this.helia = helia
     this.log = helia.logger.forComponent('helia:verified-fetch')
     this.ipns = ipns ?? heliaIpns(helia, {
-      resolvers: [
+      resolvers: init?.dnsResolvers ?? [
         dnsJsonOverHttps('https://mozilla.cloudflare-dns.com/dns-query'),
         dnsJsonOverHttps('https://dns.google/resolve')
       ]

packages/verified-fetch/test/verified-fetch.spec.ts

@@ -523,4 +523,29 @@ describe('@helia/verifed-fetch', () => {
       await expect(resp.text()).to.eventually.equal('hello world')
     })
   })
+
+  describe('custom dns-resolvers', () => {
+    it('uses custom dnsResolvers if provided', async () => {
+      const customResolver1 = Sinon.stub()
+      const customResolver2 = Sinon.stub()
+      const onProgress = Sinon.stub()
+
+      customResolver1.rejects(new Error('Could not resolve PeerId "mydomain.com"'))
+      customResolver2.returns(Promise.resolve('/ipfs/QmVP2ip92jQuMDezVSzQBWDqWFbp9nyCHNQSiciRauPLDg'))
+
+      const verifiedFetch = new VerifiedFetch({
+        helia
+      }, {
+        dnsResolvers: [customResolver1, customResolver2]
+      })
+      // ignoring error of walking the CID because we haven't actually added the block to the blockstore
+      await expect(verifiedFetch.fetch('ipns://mydomain.com', { onProgress })).to.eventually.be.rejected
+        .with.property('code', 'ERR_EXPECTED_ERR_CODE')
+      expect(customResolver1.callCount).to.equal(1)
+      expect(customResolver1.getCall(0).args).to.deep.equal(['mydomain.com', { onProgress }])
+      await expect(customResolver1.getCall(0).returnValue).to.eventually.be.rejectedWith('Could not resolve PeerId "mydomain.com"')
+      expect(customResolver2.callCount).to.equal(1)
+      expect(customResolver2.getCall(0).args).to.deep.equal(['mydomain.com', { onProgress }])
+    })
+  })
 })