From 68f4722e32d0596c73a4a74c4f2f20a0b62c5714 Mon Sep 17 00:00:00 2001
From: hannahhoward <hannah@hannahhoward.net>
Date: Mon, 18 May 2026 19:59:03 -0700
Subject: [PATCH] feat: clear extended provider via ClearExtendedProvider
 special message

Adds a new SQS special-message body 'ClearExtendedProvider' that, when
received, publishes an advertisement whose ExtendedProvider.Providers
field is explicitly empty. storetheindex >= e1afa6b8 (PR #2814) honors
this shape via its registry.Update Empty() branch, setting
info.ExtendedProviders = nil so subsequent lookups return no
ExtendedProvider entries for the publisher peer ID.

See ipni/storetheindex#1745 for the design rationale.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 src/handlers/advertisement.js | 20 ++++++++++
 test/advertisement.test.js    | 69 ++++++++++++++++++++++++++++++++++-
 2 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/src/handlers/advertisement.js b/src/handlers/advertisement.js
index de42f38..73c05c8 100644
--- a/src/handlers/advertisement.js
+++ b/src/handlers/advertisement.js
@@ -18,6 +18,9 @@ const telemetry = require('../telemetry')
 // see: https://github.com/elastic-ipfs/publisher-lambda/pull/27
 const SPECIAL_MESSAGE_ANNOUNCE_HTTP_PROVIDER = 'AnnounceHTTP'
 
+// see: https://github.com/ipni/storetheindex/pull/2814
+const SPECIAL_MESSAGE_CLEAR_EXTENDED_PROVIDER = 'ClearExtendedProvider'
+
 async function fetchHeadCid() {
   try {
     telemetry.increaseCount('http-head-cid-fetchs')
@@ -147,6 +150,7 @@ async function main(event) {
 
     for (const record of event.Records) {
       let ad
+      let clearExtendedProvider = false
 
       if (record.body === SPECIAL_MESSAGE_ANNOUNCE_HTTP_PROVIDER) {
         const http = new Provider({
@@ -158,6 +162,14 @@ async function main(event) {
           previous: headCid,
           providers: [bits, http]
         })
+      } else if (record.body === SPECIAL_MESSAGE_CLEAR_EXTENDED_PROVIDER) {
+        ad = new Advertisement({
+          previous: headCid,
+          providers: [bits],
+          entries: null,
+          context: null
+        })
+        clearExtendedProvider = true
       } else {
         const entries = CID.parse(record.body)
         const context = Buffer.from(entries.toString())
@@ -170,6 +182,14 @@ async function main(event) {
       }
 
       const value = await ad.encodeAndSign()
+      // The library only writes ExtendedProvider when providers.length > 1; attach
+      // the empty-Providers shape after signing so storetheindex's Empty() clearing
+      // path triggers (https://github.com/ipni/storetheindex/pull/2814). The AD
+      // signature covers previous+entries+provider+addresses+metadata+IsRm only,
+      // so this attachment does not invalidate it.
+      if (clearExtendedProvider) {
+        value.ExtendedProvider = { Providers: [], Override: false }
+      }
       const block = await Block.encode({ value, codec: dagJson, hasher: sha256 })
 
       // Upload the file to S3
diff --git a/test/advertisement.test.js b/test/advertisement.test.js
index 39c480a..f681a83 100644
--- a/test/advertisement.test.js
+++ b/test/advertisement.test.js
@@ -6,7 +6,7 @@ const t = require('tap')
 const varint = require('varint')
 const dagJson = require('@ipld/dag-json')
 const { MockAgent, setGlobalDispatcher } = require('undici')
-const { awsRegion, s3Bucket, indexerNodeUrl } = require('../src/config')
+const { awsRegion, s3Bucket, indexerNodeUrl, bitswapPeerMultiaddr } = require('../src/config')
 const { handler } = require('../src/index')
 const { trackAWSUsages, mockPeerIds } = require('./utils/mock')
 
@@ -291,3 +291,70 @@ t.test('advertisement - handles indexer announcing generic error', async t => {
     { message: 'ERROR' }
   )
 })
+
+t.test('advertisement - clear extended provider', async t => {
+  t.plan(18)
+
+  const mockAgent = new MockAgent()
+  const mockHeadPool = mockAgent.get(`https://${s3Bucket}.s3.${awsRegion}.amazonaws.com`)
+  const mockIndexerPool = mockAgent.get(indexerNodeUrl)
+  mockPeerIds()
+
+  const head = 'baguqeeralr4pwxvbcc6voioqyc6aneg4pkoh5rhrfj35gbhrpxpeavsh6vsa'
+  mockAgent.disableNetConnect()
+  mockHeadPool
+    .intercept({ method: 'GET', path: '/head' })
+    .reply(200, `{"head": {"/": "${head}"}}`, {
+      headers: { 'content-type': 'application/json' }
+    })
+  mockIndexerPool
+    .intercept({
+      method: 'PUT',
+      path: '/ingest/announce'
+    })
+    .reply(204, '')
+
+  trackAWSUsages(t)
+  setGlobalDispatcher(mockAgent)
+
+  t.strictSame(
+    await handler({
+      Records: [
+        { body: 'ClearExtendedProvider' }
+      ]
+    }),
+    {}
+  )
+
+  t.equal(t.context.s3.puts.length, 2)
+  t.equal(t.context.s3.puts[0].Bucket, s3Bucket)
+  t.ok(t.context.s3.puts[0].Key.startsWith('bagu'))
+  t.equal(t.context.s3.puts[1].Bucket, s3Bucket)
+  t.equal(t.context.s3.puts[1].Key, 'head')
+
+  const ad = dagJson.decode(t.context.s3.puts[0].Body)
+
+  // AC6 chain continuity
+  t.equal(ad.PreviousID.toString(), head)
+
+  // AC3 ExtendedProvider field present with empty Providers array
+  t.ok(ad.ExtendedProvider)
+  t.ok(Array.isArray(ad.ExtendedProvider.Providers))
+  t.equal(ad.ExtendedProvider.Providers.length, 0)
+
+  // AC4 Override field present (value not locked)
+  t.ok('Override' in ad.ExtendedProvider)
+
+  // AC5 base provider unchanged - Addresses
+  t.ok(Array.isArray(ad.Addresses))
+  t.equal(ad.Addresses.length, 1)
+  t.equal(ad.Addresses[0], bitswapPeerMultiaddr)
+
+  // AC5 base provider unchanged - Provider peer ID
+  t.equal(typeof ad.Provider, 'string')
+  t.ok(ad.Provider.length > 0)
+
+  // AC7 signature present
+  t.ok(ad.Signature instanceof Uint8Array || Buffer.isBuffer(ad.Signature))
+  t.ok(ad.Signature.length > 0)
+})