Allow custom input schema types

Author: stevensJourney

docs/collections/powersync-collection.md

@@ -101,7 +101,7 @@ const documentsCollection = createCollection(
 
 #### Option 2: Using Advanced Schema Validation
 
-Additional validations can be performed by supplying a compatible validation schema (such as a Zod schema). The typing of the validator is constrained to match the typing of the SQLite table.
+Additional validations can be performed by supplying a compatible validation schema (such as a Zod schema). The output typing of the validator is constrained to match the typing of the SQLite table. The input typing can be arbitrary.
 
 ```ts
 import { createCollection } from "@tanstack/react-db"
@@ -111,10 +111,7 @@ import { z } from "zod"
 // The output of this schema must match the SQLite schema
 const schema = z.object({
   id: z.string(),
-  name: z
-    .string()
-    .min(3, { message: "Should be at least 3 characters" })
-    .nullable(),
+  name: z.string().min(3, { message: "Should be at least 3 characters" }),
 })
 
 const documentsCollection = createCollection(

packages/powersync-db-collection/src/powersync.ts

@@ -6,7 +6,11 @@ import { PowerSyncTransactor } from "./PowerSyncTransactor"
 import { convertTableToSchema } from "./schema"
 import type { Table, TriggerDiffRecord } from "@powersync/common"
 import type { StandardSchemaV1 } from "@standard-schema/spec"
-import type { CollectionConfig, SyncConfig } from "@tanstack/db"
+import type {
+  CollectionConfig,
+  InferSchemaOutput,
+  SyncConfig,
+} from "@tanstack/db"
 import type {
   EnhancedPowerSyncCollectionConfig,
   PowerSyncCollectionConfig,
@@ -91,13 +95,10 @@ export function powerSyncCollectionOptions<TTable extends Table = Table>(
  */
 export function powerSyncCollectionOptions<
   TTable extends Table,
-  TSchema extends StandardSchemaV1<
-    ExtractedTable<TTable>,
-    ExtractedTable<TTable>
-  >,
+  TSchema extends StandardSchemaV1<any, ExtractedTable<TTable>>,
 >(
   config: PowerSyncCollectionConfig<TTable, TSchema>
-): CollectionConfig<ExtractedTable<TTable>, string, TSchema> & {
+): CollectionConfig<InferSchemaOutput<TSchema>, string, TSchema> & {
   utils: PowerSyncCollectionUtils
   schema: TSchema
 }

packages/powersync-db-collection/tests/powersync.test.ts

@@ -156,6 +156,35 @@ describe(`PowerSync Integration`, () => {
         }
       }
     })
+
+    it(`should allow custom input types`, async () => {
+      const db = await createDatabase()
+
+      // The input can be arbitrarily typed, as long as it converts to SQLite
+      const schema = z.object({
+        id: z.string(),
+        name: z.number().transform((val) => `Number: ${val}`),
+      })
+
+      const collection = createCollection(
+        powerSyncCollectionOptions({
+          database: db,
+          table: APP_SCHEMA.props.documents,
+          schema,
+        })
+      )
+      onTestFinished(() => collection.cleanup())
+
+      const id = randomUUID()
+      collection.insert({
+        id,
+        name: 42,
+      })
+
+      const item = collection.get(id)
+
+      expect(item?.name).eq(`Number: 42`)
+    })
   })
 
   describe(`sync`, () => {