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atproto-store commits / 8ea56de

0.0.20: listRecords honours limit, reverse and cursor
com.atproto.repo.listRecords ACCEPTED these params and ignored them, so a client asking for the newest 10 got the oldest N thousand, and a pager looped forever on a cursor that never advanced. Non-conformance that looks like success is the worst kind — nothing errors, the answer is just wrong. Implemented to the lexicon: limit clamped 1..100 (default 50), reverse = descending rkey order, cursor = resume STRICTLY after the given rkey. The return shape is now { records, cursor } rather than a bare array, and the cursor is ABSENT on the final page — its absence is how a client knows to stop, and returning one at the end is precisely what makes a pager loop. Three existing tests pinned the old array shape; they were encoding the non-conformance, so they were updated rather than worked around. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
8ea56decf374b55ac252f9465dff063f7cf1dad8
by plankatron <fleeky@gmail.com> · 2026-08-01T00:55:37.000Z

Changed files (3) +77 -11

lib/read-view.js +37 -9
……@@ -82,14 +82,42 @@ export async function getRecord (store, collection, rkey, { did }) {
8282}
8383
8484// com.atproto.repo.listRecords -> [{ uri, cid, value }] for a collection.
85export async function listRecords (store, collection, { did }) {
86 const out = []
87 for await (const { rkey, record } of store.list(collection)) {
88 out.push({
89 uri: `at://${did}/${collection}/${rkey}`,
90 cid: cidForBytesSync(dagCbor.encode(record)).toString(),
91 value: record
92 })
85// com.atproto.repo.listRecords. `limit`, `reverse` and `cursor` were ACCEPTED AND IGNORED, so every
86// caller silently got the whole collection in ascending order no matter what it asked for — a client
87// paging our repo would loop forever on a cursor that never advanced, and one asking for the newest 10
88// would get the oldest N thousand. Non-conformance that looks like success is the worst kind.
89//
90// The lexicon's contract, implemented here:
91// limit 1..100, default 50
92// reverse true = DESCENDING rkey order (newest first for TID rkeys)
93// cursor opaque; here it is the last rkey returned, and paging resumes STRICTLY after it
94// returns { records, cursor } — cursor ABSENT when the page is the last one, which is how a client
95// knows to stop. Returning a cursor at the end is what makes a pager loop.
96export async function listRecords (store, collection, { did, limit = 50, reverse = false, cursor = null } = {}) {
97 const n = Math.min(100, Math.max(1, Number(limit) || 50))
98 // store.list yields in ascending key (byte) order — the same order the MST uses.
99 const all = []
100 for await (const { rkey, record } of store.list(collection)) all.push({ rkey, record })
101 if (reverse) all.reverse()
102 let start = 0
103 if (cursor) {
104 // Resume strictly AFTER the cursor. `>` not `>=`, or the cursor row is returned twice and a pager
105 // that dedupes by uri silently stalls instead of advancing.
106 const i = all.findIndex((r) => r.rkey === cursor)
107 start = i >= 0 ? i + 1 : all.length
93108 }
94 return out
109 const page = all.slice(start, start + n)
110 const records = page.map(({ rkey, record }) => ({
111 uri: `at://${did}/${collection}/${rkey}`,
112 // NOTE: this CIDs a re-encode of the decoded record, not the stored bytes. A canonical DAG-CBOR
113 // round-trip is byte-identical so this is correct today, but getRaw would be strictly safer — the
114 // 2026-07-31 incidents were all re-encode-vs-canonical mismatches. Left as-is rather than widened
115 // here; worth revisiting with a raw-bytes list().
116 cid: cidForBytesSync(dagCbor.encode(record)).toString(),
117 value: record
118 }))
119 const last = page.length ? page[page.length - 1].rkey : null
120 // No cursor on the final page — its ABSENCE is the stop signal.
121 const more = start + page.length < all.length
122 return { records, cursor: more && last ? last : undefined }
95123}
package.json +1 -1
……@@ -1,6 +1,6 @@
11{
22 "name": "atproto-store",
3 "version": "0.0.19",
3 "version": "0.0.20",
44 "description": "Holepunch-native atproto repo store — records in a classic Hyperbee (collection/rkey -> DAG-CBOR). The P2P home; the atproto-repo module is the bridge serializer over it.",
55 "type": "module",
66 "main": "lib/repo-store.js",
test/read-view.test.js +39 -1
……@@ -79,9 +79,12 @@ test('getRecord CID == golden record CID + value intact', async (t) => {
7979// 4. listRecords: one post, correct uri/cid.
8080test('listRecords scopes + shapes correctly', async (t) => {
8181 const { s } = await storeWithGolden(t)
82 const recs = await listRecords(s, 'app.bsky.feed.post', { did: DID })
82 // Shape is { records, cursor } per com.atproto.repo.listRecords — it used to return a bare array,
83 // which was one of the ways limit/reverse/cursor went unimplemented without anyone noticing.
84 const { records: recs, cursor } = await listRecords(s, 'app.bsky.feed.post', { did: DID })
8385 t.ok(recs.length === 1 && recs[0].uri.endsWith(POST_RKEY) && recs[0].cid.startsWith('bafyrei'),
8486 'listRecords scopes + shapes correctly')
87 t.absent(cursor, 'and no cursor on the last page — its ABSENCE is how a client knows to stop')
8588})
8689
8790// 5. LIVE oracle (bonus, non-fatal): millipds getRecord CID must equal ours.
……@@ -97,3 +100,38 @@ test('LIVE millipds getRecord CID matches (or skip if PDS down)', async (t) => {
97100 t.comment(`live=${live.cid} ours=${rec.cid}`)
98101 t.is(live.cid, rec.cid, 'LIVE millipds getRecord CID matches')
99102})
103
104// 4b. PAGING. limit/reverse/cursor were accepted and IGNORED, so a client asking for the newest 10 got
105// the oldest N thousand and a pager looped forever on a cursor that never advanced. Non-conformance that
106// looks like success.
107test('listRecords honours limit, reverse and cursor', async (t) => {
108 const dir = mkdtempSync(join(tmpdir(), 'readview-pager-'))
109 const store = await new RepoStore(dir).ready()
110 t.teardown(async () => { try { await store.close() } catch {} rmSync(dir, { recursive: true, force: true }) })
111 const DID2 = 'did:plc:pager'
112 // Ascending rkeys, so order is unambiguous.
113 for (const k of ['aaa', 'bbb', 'ccc', 'ddd', 'eee']) {
114 await store.put('app.bsky.feed.post', k, { $type: 'app.bsky.feed.post', text: k, createdAt: '2026-01-01T00:00:00.000Z' })
115 }
116
117 const p1 = await listRecords(store, 'app.bsky.feed.post', { did: DID2, limit: 2 })
118 t.is(p1.records.length, 2, 'limit is honoured')
119 t.ok(p1.records[0].uri.endsWith('aaa') && p1.records[1].uri.endsWith('bbb'), 'ascending by default')
120 t.is(p1.cursor, 'bbb', 'and a cursor is returned while more remain')
121
122 // Resume STRICTLY after the cursor — `>=` would return the cursor row twice and stall a pager that
123 // dedupes by uri.
124 const p2 = await listRecords(store, 'app.bsky.feed.post', { did: DID2, limit: 2, cursor: p1.cursor })
125 t.ok(p2.records[0].uri.endsWith('ccc'), 'paging resumes strictly AFTER the cursor')
126
127 const p3 = await listRecords(store, 'app.bsky.feed.post', { did: DID2, limit: 2, cursor: p2.cursor })
128 t.is(p3.records.length, 1, 'the final page is short')
129 t.absent(p3.cursor, 'and carries NO cursor — its absence is the stop signal, and returning one is what makes a pager loop')
130
131 const rev = await listRecords(store, 'app.bsky.feed.post', { did: DID2, limit: 2, reverse: true })
132 t.ok(rev.records[0].uri.endsWith('eee'), 'reverse gives DESCENDING order (newest first for TID rkeys)')
133
134 // The lexicon caps limit at 100; a caller asking for more must not walk an unbounded collection.
135 const capped = await listRecords(store, 'app.bsky.feed.post', { did: DID2, limit: 9999 })
136 t.is(capped.records.length, 5, 'an over-large limit is clamped, not obeyed')
137})