refactor: only use low-level block api in refs-local interface test

Follows on from #2980 but uses the unixfs-importer which has been
refactored to only use the block API, allowing implementations to be
written from low-level APIs upwards.

packages/interface-ipfs-core/package.json

@@ -38,13 +38,15 @@
     "dirty-chai": "^2.0.1",
     "ipfs-block": "^0.8.1",
     "ipfs-unixfs": "^1.0.1",
+    "ipfs-unixfs-importer": "^2.0.0",
     "ipfs-utils": "^2.2.0",
     "ipld-dag-cbor": "^0.15.1",
     "ipld-dag-pb": "^0.18.3",
     "is-ipfs": "^1.0.0",
     "iso-random-stream": "^1.1.1",
     "it-all": "^1.0.1",
     "it-concat": "^1.0.0",
+    "it-drain": "^1.0.0",
     "it-last": "^1.0.1",
     "it-pushable": "^1.3.1",
     "multiaddr": "^7.2.1",

packages/interface-ipfs-core/src/refs-local.js

@@ -4,6 +4,8 @@
 const { fixtures } = require('./utils')
 const { getDescribe, getIt, expect } = require('./utils/mocha')
 const all = require('it-all')
+const drain = require('it-drain')
+const importer = require('ipfs-unixfs-importer')
 
 /** @typedef { import("ipfsd-ctl/src/factory") } Factory */
 /**
@@ -36,7 +38,7 @@ module.exports = (common, options) => {
         content('holmes.txt')
       ]
 
-      await all(ipfs.add(dirs))
+      await drain(importer(dirs, ipfs.block))
 
       const refs = await all(ipfs.refs.local())