feat: fetch specific feed index update (#629)

src/feed/index.ts

@@ -1,7 +1,7 @@
 import { keccak256Hash } from '../utils/hash'
 import { serializeBytes } from '../chunk/serialize'
 import { Identifier, uploadSingleOwnerChunkData, makeSingleOwnerChunkFromData } from '../chunk/soc'
-import { FeedUpdateOptions, fetchFeedUpdate } from '../modules/feed'
+import { FeedUpdateOptions, fetchLatestFeedUpdate, FetchFeedUpdateResponse } from '../modules/feed'
 import {
   REFERENCE_HEX_LENGTH,
   Reference,
@@ -38,6 +38,7 @@ export interface Epoch {
   time: number
   level: number
 }
+
 export type IndexBytes = Bytes<8>
 export type Index = number | Epoch | IndexBytes | string
 
@@ -110,7 +111,7 @@ export async function findNextIndex(
   options?: FeedUpdateOptions,
 ): Promise<HexString<typeof INDEX_HEX_LENGTH>> {
   try {
-    const feedUpdate = await fetchFeedUpdate(ky, owner, topic, options)
+    const feedUpdate = await fetchLatestFeedUpdate(ky, owner, topic, options)
 
     return makeHexString(feedUpdate.feedIndexNext, INDEX_HEX_LENGTH)
   } catch (e) {
@@ -165,13 +166,23 @@ export async function downloadFeedUpdate(ky: Ky, owner: EthAddress, topic: Topic
 }
 
 export function makeFeedReader(ky: Ky, type: FeedType, topic: Topic, owner: HexEthAddress): FeedReader {
-  const download = async (options?: FeedUpdateOptions) => fetchFeedUpdate(ky, owner, topic, { ...options, type })
-
   return {
     type,
     owner,
     topic,
-    download,
+    async download(options?: FeedUpdateOptions): Promise<FetchFeedUpdateResponse> {
+      if (!options?.index) {
+        return fetchLatestFeedUpdate(ky, owner, topic, { ...options, type })
+      }
+
+      const update = await downloadFeedUpdate(ky, hexToBytes(owner), topic, options.index)
+
+      return {
+        reference: bytesToHex(update.reference),
+        feedIndex: options.index,
+        feedIndexNext: '',
+      }
+    },
   }
 }
 

src/modules/feed.ts

@@ -16,14 +16,28 @@ export interface FeedUpdateOptions {
    * Specifies the start date as unix time stamp
    */
   at?: number
+
   /**
    * Can be 'epoch' or 'sequence' (default: 'sequence')
    */
   type?: FeedType
+
+  /**
+   * Fetch specific previous Feed's update (default fetches latest update)
+   */
+  index?: string
 }
 
 interface FeedUpdateHeaders {
+  /**
+   * The current feed's index
+   */
   feedIndex: string
+
+  /**
+   * The feed's index for next update.
+   * Only set for the latest update. If update is fetched using previous index, then this is an empty string.
+   */
   feedIndexNext: string
 }
 export interface FetchFeedUpdateResponse extends ReferenceResponse, FeedUpdateHeaders {}
@@ -86,7 +100,7 @@ function readFeedUpdateHeaders(headers: Headers): FeedUpdateHeaders {
  * @param topic       Topic in hex
  * @param options     Additional options, like index, at, type
  */
-export async function fetchFeedUpdate(
+export async function fetchLatestFeedUpdate(
   ky: Ky,
   owner: HexEthAddress,
   topic: Topic,

test/integration/bee-class.spec.ts

@@ -1,4 +1,4 @@
-import { Bee, BeeDebug, Collection, PssSubscription } from '../../src'
+import { Bee, BeeDebug, BeeResponseError, Collection, PssSubscription } from '../../src'
 import { makeSigner } from '../../src/chunk/signer'
 import { makeSOCAddress, uploadSingleOwnerChunkData } from '../../src/chunk/soc'
 import { ChunkReference } from '../../src/feed'
@@ -444,11 +444,12 @@ describe('Bee class', () => {
   describe('feeds', () => {
     const owner = testIdentity.address
     const signer = testIdentity.privateKey
-    const topic = randomByteArray(32, Date.now())
 
     it(
-      'feed writer with two updates',
+      'should write two updates',
       async () => {
+        const topic = randomByteArray(32, Date.now())
+
         const feed = bee.makeFeedWriter('sequence', topic, signer)
         const referenceZero = makeBytes(32) // all zeroes
 
@@ -472,9 +473,75 @@ describe('Bee class', () => {
       FEED_TIMEOUT,
     )
 
+    it(
+      'should get specific feed update',
+      async () => {
+        const topic = randomByteArray(32, Date.now())
+
+        const feed = bee.makeFeedWriter('sequence', topic, signer)
+        const referenceZero = makeBytes(32) // all zeroes
+
+        await feed.upload(getPostageBatch(), referenceZero)
+
+        const firstLatestUpdate = await feed.download()
+        expect(firstLatestUpdate.reference).toEqual(bytesToHex(referenceZero))
+        expect(firstLatestUpdate.feedIndex).toEqual('0000000000000000')
+
+        const referenceOne = new Uint8Array([...new Uint8Array([1]), ...new Uint8Array(31)]) as ChunkReference
+        await feed.upload(getPostageBatch(), referenceOne)
+
+        const secondLatestUpdate = await feed.download()
+        expect(secondLatestUpdate.reference).toEqual(bytesToHex(referenceOne))
+        expect(secondLatestUpdate.feedIndex).toEqual('0000000000000001')
+
+        const referenceTwo = new Uint8Array([
+          ...new Uint8Array([1]),
+          ...new Uint8Array([1]),
+          ...new Uint8Array(30),
+        ]) as ChunkReference
+        await feed.upload(getPostageBatch(), referenceTwo)
+
+        const thirdLatestUpdate = await feed.download()
+        expect(thirdLatestUpdate.reference).toEqual(bytesToHex(referenceTwo))
+        expect(thirdLatestUpdate.feedIndex).toEqual('0000000000000002')
+
+        const sendBackFetchedUpdate = await feed.download({ index: '0000000000000001' })
+        expect(sendBackFetchedUpdate.reference).toEqual(bytesToHex(referenceOne))
+        expect(sendBackFetchedUpdate.feedIndex).toEqual('0000000000000001')
+      },
+      FEED_TIMEOUT,
+    )
+    it(
+      'should fail fetching non-existing index',
+      async () => {
+        const topic = randomByteArray(32, Date.now())
+
+        const feed = bee.makeFeedWriter('sequence', topic, signer)
+        const referenceZero = makeBytes(32) // all zeroes
+        await feed.upload(getPostageBatch(), referenceZero)
+
+        const firstLatestUpdate = await feed.download()
+        expect(firstLatestUpdate.reference).toEqual(bytesToHex(referenceZero))
+        expect(firstLatestUpdate.feedIndex).toEqual('0000000000000000')
+
+        try {
+          await feed.download({ index: '0000000000000001' })
+          throw new Error('Should fail')
+        } catch (err) {
+          const e = err as BeeResponseError
+
+          expect(e.status).toEqual(404)
+          expect(e.responseBody).toContain('chunk not found')
+        }
+      },
+      FEED_TIMEOUT,
+    )
+
     it(
       'create feeds manifest and retrieve the data',
       async () => {
+        const topic = randomByteArray(32, Date.now())
+
         const directoryStructure: Collection<Uint8Array> = [
           {
             path: 'index.html',

test/integration/feed/index.spec.ts

@@ -1,4 +1,4 @@
-import { fetchFeedUpdate } from '../../../src/modules/feed'
+import { fetchLatestFeedUpdate } from '../../../src/modules/feed'
 import { hexToBytes, makeHexString } from '../../../src/utils/hex'
 import { beeKy, ERR_TIMEOUT, getPostageBatch, testIdentity } from '../../utils'
 import { ChunkReference, downloadFeedUpdate, findNextIndex, Index, uploadFeedUpdate } from '../../../src/feed'
@@ -56,7 +56,7 @@ describe('feed', () => {
     const uploadedChunk = await uploadChunk(BEE_KY, 0)
     await tryUploadFeedUpdate(BEE_KY, signer, topic, 0, uploadedChunk)
 
-    const feedUpdate = await fetchFeedUpdate(BEE_KY, owner, topic)
+    const feedUpdate = await fetchLatestFeedUpdate(BEE_KY, owner, topic)
 
     expect(feedUpdate.feedIndex).toEqual('0000000000000000')
     expect(feedUpdate.feedIndexNext).toEqual('0000000000000001')

test/integration/modules/feed.spec.ts

@@ -1,4 +1,4 @@
-import { createFeedManifest, fetchFeedUpdate } from '../../../src/modules/feed'
+import { createFeedManifest, fetchLatestFeedUpdate } from '../../../src/modules/feed'
 import { HexString, hexToBytes, makeHexString } from '../../../src/utils/hex'
 import {
   beeKy,
@@ -29,7 +29,7 @@ describe('modules/feed', () => {
     'empty feed update',
     async () => {
       const emptyTopic = '1000000000000000000000000000000000000000000000000000000000000000' as Topic
-      const feedUpdate = fetchFeedUpdate(BEE_KY, owner, emptyTopic)
+      const feedUpdate = fetchLatestFeedUpdate(BEE_KY, owner, emptyTopic)
 
       await expect(feedUpdate).rejects.toThrow('Not Found')
     },
@@ -53,7 +53,7 @@ describe('modules/feed', () => {
     const socResponse = await uploadSOC(BEE_KY, owner, identifier, signature, socData, getPostageBatch())
     expect(socResponse).toBeType('string')
 
-    const feedUpdate = await fetchFeedUpdate(BEE_KY, owner, oneUpdateTopic)
+    const feedUpdate = await fetchLatestFeedUpdate(BEE_KY, owner, oneUpdateTopic)
     expect(feedUpdate.reference).toBeType('string')
     expect(feedUpdate.feedIndex).toEqual('0000000000000000')
     expect(feedUpdate.feedIndexNext).toEqual('0000000000000001')