fix: get discovery key from core.key

core.discoveryKey is null when the hypercore is first initialized.
We ensure that core.key is always defined, but `core.discoveryKey`
is a getter, so we can't override that.

index.js

@@ -3,6 +3,7 @@ const { Writable } = require('streamx')
 const { TypedEmitter } = require('tiny-typed-emitter')
 const { once } = require('events')
 const raf = require('random-access-file')
+const { discoveryKey } = require('hypercore-crypto')
 // const log = require('debug')('multi-core-indexer')
 const { CoreIndexStream } = require('./lib/core-index-stream')
 const { MultiCoreIndexStream } = require('./lib/multi-core-index-stream')
@@ -174,9 +175,8 @@ class MultiCoreIndexer extends TypedEmitter {
 
 module.exports = MultiCoreIndexer
 
-/** @param {{ discoveryKey: null | Buffer }} core */
+/** @param {{ key: Buffer }} core */
 function getStorageName(core) {
-  // @ts-expect-error - we want this to throw if core.discoveryKey is nullish
-  const id = core.discoveryKey.toString('hex')
+  const id = discoveryKey(core.key).toString('hex')
   return [id.slice(0, 2), id.slice(2, 4), id].join('/')
 }

package.json

@@ -22,6 +22,7 @@
     "b4a": "^1.6.4",
     "big-sparse-array": "^1.0.2",
     "debug": "^4.3.3",
+    "hypercore-crypto": "^3.4.0",
     "random-access-file": "^4.0.4",
     "streamx": "^2.15.0",
     "tiny-typed-emitter": "^2.1.0"

vendor/types/hypercore-crypto.d.ts

@@ -0,0 +1,3 @@
+declare module 'hypercore-crypto' {
+  export function discoveryKey(key: Buffer): Buffer
+}