Add initial TrailBase integration and tests.

Author: ignatz

packages/db-collections/package.json

@@ -6,7 +6,8 @@
     "@tanstack/db": "workspace:*",
     "@tanstack/query-core": "^5.75.7",
     "@standard-schema/spec": "^1.0.0",
-    "@tanstack/store": "^0.7.0"
+    "@tanstack/store": "^0.7.0",
+    "trailbase": "^0.7.1"
   },
   "devDependencies": {
     "@electric-sql/client": "1.0.0",

packages/db-collections/src/index.ts

@@ -15,3 +15,8 @@ export {
   type StorageApi,
   type StorageEventApi,
 } from "./local-storage"
+export {
+  trailBaseCollectionOptions,
+  type TrailBaseCollectionConfig,
+  type TrailBaseCollectionUtils,
+} from "./trailbase"

packages/db-collections/src/trailbase.ts

@@ -0,0 +1,243 @@
+/* eslint-disable @typescript-eslint/no-unnecessary-condition */
+import { Store } from "@tanstack/store"
+import type { Event, RecordApi } from "trailbase"
+
+import type { CollectionConfig, SyncConfig, UtilsRecord } from "@tanstack/db"
+
+/**
+ * Configuration interface for TrailbaseCollection
+ */
+export interface TrailBaseCollectionConfig<
+  TItem extends object,
+  TKey extends string | number = string | number,
+> extends Omit<
+    CollectionConfig<TItem, TKey>,
+    `sync` | `onInsert` | `onUpdate` | `onDelete`
+  > {
+  /**
+   * Record API name
+   */
+  recordApi: RecordApi<TItem>
+}
+
+export type AwaitTxIdFn = (txId: string, timeout?: number) => Promise<boolean>
+
+export interface TrailBaseCollectionUtils extends UtilsRecord {
+  cancel: () => void
+}
+
+export function trailBaseCollectionOptions<TItem extends object>(
+  config: TrailBaseCollectionConfig<TItem>
+): CollectionConfig<TItem> & { utils: TrailBaseCollectionUtils } {
+  const getKey = config.getKey
+
+  const seenIds = new Store(new Map<string, number>())
+
+  const awaitIds = (
+    ids: Array<string>,
+    timeout: number = 120 * 1000
+  ): Promise<void> => {
+    const completed = (value: Map<string, number>) =>
+      ids.every((id) => value.has(id))
+    if (completed(seenIds.state)) {
+      return Promise.resolve()
+    }
+
+    return new Promise<void>((resolve, reject) => {
+      const timeoutId = setTimeout(() => {
+        unsubscribe()
+        reject(new Error(`Timeout waiting for ids: ${ids}`))
+      }, timeout)
+
+      const unsubscribe = seenIds.subscribe((value) => {
+        if (completed(value.currentVal)) {
+          clearTimeout(timeoutId)
+          unsubscribe()
+          resolve()
+        }
+      })
+    })
+  }
+
+  const weakSeenIds = new WeakRef(seenIds)
+  const cleanupTimer = setInterval(() => {
+    const seen = weakSeenIds.deref()
+    if (seen) {
+      seen.setState((curr) => {
+        const now = Date.now()
+        let anyExpired = false
+
+        const notExpired = Array.from(curr.entries()).filter(([_, v]) => {
+          const expired = now - v > 300 * 1000
+          anyExpired = anyExpired || expired
+          return !expired
+        })
+
+        if (anyExpired) {
+          return new Map(notExpired)
+        }
+        return curr
+      })
+    } else {
+      clearInterval(cleanupTimer)
+    }
+  }, 120 * 1000)
+
+  type SyncParams = Parameters<SyncConfig<TItem>[`sync`]>[0]
+
+  let eventReader: ReadableStreamDefaultReader<Event> | undefined
+  const sync = {
+    sync: (params: SyncParams) => {
+      const { begin, write, commit } = params
+
+      // Initial fetch.
+      async function initialFetch() {
+        const limit = 256
+        let response = await config.recordApi.list({
+          pagination: {
+            limit,
+          },
+        })
+        let cursor = response.cursor
+        let got = 0
+
+        begin()
+
+        while (true) {
+          const length = response.records.length
+          if (length === 0) break
+
+          got = got + length
+          for (const item of response.records) {
+            write({ type: `insert`, value: item })
+          }
+
+          if (length < limit) break
+
+          response = await config.recordApi.list({
+            pagination: {
+              limit,
+              cursor,
+              offset: cursor === undefined ? got : undefined,
+            },
+          })
+          cursor = response.cursor
+        }
+
+        commit()
+      }
+
+      // Afterwards subscribe.
+      async function subscribe() {
+        const eventStream = await config.recordApi.subscribe(`*`)
+        const reader = (eventReader = eventStream.getReader())
+
+        while (true) {
+          const { done, value: event } = await reader.read()
+
+          if (done || !event) {
+            reader.releaseLock()
+            eventReader = undefined
+            return
+          }
+
+          begin()
+          let value: TItem | undefined
+          if (`Insert` in event) {
+            value = event.Insert as TItem
+            write({ type: `insert`, value })
+          } else if (`Delete` in event) {
+            value = event.Delete as TItem
+            write({ type: `delete`, value })
+          } else if (`Update` in event) {
+            value = event.Update as TItem
+            write({ type: `update`, value })
+          } else {
+            console.error(`Error: ${event.Error}`)
+          }
+          commit()
+
+          if (value) {
+            seenIds.setState((curr) => {
+              const newIds = new Map(curr)
+              newIds.set(String(getKey(value)), Date.now())
+              return newIds
+            })
+          }
+        }
+      }
+
+      initialFetch().then(() => subscribe())
+    },
+    // Expose the getSyncMetadata function
+    getSyncMetadata: undefined,
+  }
+
+  return {
+    sync,
+    getKey,
+    onInsert: async (params): Promise<Array<number | string>> => {
+      const ids = await config.recordApi.createBulk(
+        params.transaction.mutations.map((tx) => {
+          const { type, changes } = tx
+          if (type !== `insert`) {
+            throw new Error(`Expected 'insert', got: ${type}`)
+          }
+          return changes as TItem
+        })
+      )
+
+      // The optimistic mutation overlay is removed on return, so at this point
+      // we have to ensure that the new record was properly added to the local
+      // DB by the subscription.
+      await awaitIds(ids.map((id) => String(id)))
+
+      return ids
+    },
+    onUpdate: async (params) => {
+      const ids: Array<string> = await Promise.all(
+        params.transaction.mutations.map(async (tx) => {
+          const { type, changes, key } = tx
+          if (type !== `update`) {
+            throw new Error(`Expected 'update', got: ${type}`)
+          }
+
+          await config.recordApi.update(key, changes)
+          return String(key)
+        })
+      )
+
+      // The optimistic mutation overlay is removed on return, so at this point
+      // we have to ensure that the new record was properly updated in the local
+      // DB by the subscription.
+      await awaitIds(ids)
+    },
+    onDelete: async (params) => {
+      const ids: Array<string> = await Promise.all(
+        params.transaction.mutations.map(async (tx) => {
+          const { type, key } = tx
+          if (type !== `delete`) {
+            throw new Error(`Expected 'delete', got: ${type}`)
+          }
+
+          await config.recordApi.delete(key)
+          return String(key)
+        })
+      )
+
+      // The optimistic mutation overlay is removed on return, so at this point
+      // we have to ensure that the new record was properly updated in the local
+      // DB by the subscription.
+      await awaitIds(ids)
+    },
+    utils: {
+      cancel: () => {
+        if (eventReader) {
+          eventReader.cancel()
+          eventReader.releaseLock()
+          eventReader = undefined
+        }
+      },
+    },
+  }
+}