Fix singleton lists to use Int @id @default(1) matching Keystone 6 (#352)

* Fix singleton lists to use Int @id @default(1) matching Keystone 6 behaviour

Singleton lists (isSingleton: true) previously generated String @id @default(cuid())
in the Prisma schema, which differed from Keystone 6's Int @id with a value always
set to 1. This caused data loss issues when migrating from Keystone 6 as the integer
primary key could not be automatically converted to text.

Changes:
- Prisma schema generator now emits `Int @id @default(1)` for singleton lists
- Context create function injects `id: 1` into singleton record creation data
- Types generator uses `id: number` in Output type for singleton lists
- Blog example schema updated to reflect new singleton ID type
- Tests updated to use numeric ID (1) for singleton records
- Added explicit tests for singleton schema generation

Fixes #350

https://claude.ai/code/session_01Keyrjjdhy3ypkZNzeg34re

* Run pnpm format

https://claude.ai/code/session_01Keyrjjdhy3ypkZNzeg34re

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: borisno2

.changeset/fix-singleton-int-id.md

@@ -0,0 +1,35 @@
+---
+'@opensaas/stack-core': patch
+'@opensaas/stack-cli': patch
+---
+
+Fix singleton lists to use `Int @id @default(1)` matching Keystone 6 behaviour
+
+Singleton lists now generate `Int @id @default(1)` in the Prisma schema instead of
+`String @id @default(cuid())`. This matches Keystone 6's behaviour where singleton
+records always use integer primary key `1`, making migration from Keystone 6 straightforward
+without data loss.
+
+**Migration guide for existing singleton lists:**
+
+If you have an existing database with singleton models that use `String @id`, you will need
+to run an SQL migration to convert the id column from text to integer:
+
+```sql
+-- Example for PostgreSQL (adjust table name as needed)
+ALTER TABLE "EmailSettings" ALTER COLUMN id TYPE INTEGER USING id::integer;
+UPDATE "EmailSettings" SET id = 1;
+```
+
+For SQLite (which does not support ALTER COLUMN):
+
+```sql
+-- Recreate the table with Int id
+CREATE TABLE "EmailSettings_new" (id INTEGER PRIMARY KEY DEFAULT 1, ...);
+INSERT INTO "EmailSettings_new" SELECT 1, ... FROM "EmailSettings";
+DROP TABLE "EmailSettings";
+ALTER TABLE "EmailSettings_new" RENAME TO "EmailSettings";
+```
+
+New projects and fresh databases will work automatically without any migration steps.
+Fixes #350.

examples/blog/prisma/schema.prisma

@@ -8,7 +8,7 @@ datasource db {
 }
 
 model Settings {
-  id              String   @id @default(cuid())
+  id              Int      @id @default(1)
   siteName        String
   maintenanceMode Boolean  @default(false)
   maxUploadSize   Int?

packages/cli/src/generator/__snapshots__/prisma.test.ts.snap

@@ -175,6 +175,26 @@ datasource db {
 "
 `;
 
+exports[`Prisma Schema Generator > select field with enum type > should generate singleton model with Int @id @default(1) 1`] = `
+"generator client {
+  provider = "prisma-client"
+  output   = "../.opensaas/prisma-client"
+}
+
+datasource db {
+  provider = "sqlite"
+}
+
+model Settings {
+  id        Int      @id @default(1)
+  siteName     String
+  maintenanceMode Boolean @default(false)
+  createdAt DateTime @default(now())
+  updatedAt DateTime @default(now()) @updatedAt
+}
+"
+`;
+
 exports[`Prisma Schema Generator > select field with enum type > should match snapshot for enum select field 1`] = `
 "generator client {
   provider = "prisma-client"

packages/cli/src/generator/prisma.test.ts

@@ -1543,5 +1543,48 @@ describe('Prisma Schema Generator', () => {
       const schema = generatePrismaSchema(config)
       expect(schema).toMatchSnapshot()
     })
+
+    it('should generate singleton model with Int @id @default(1)', () => {
+      const config: OpenSaasConfig = {
+        db: {
+          provider: 'sqlite',
+        },
+        lists: {
+          Settings: {
+            fields: {
+              siteName: text({ validation: { isRequired: true } }),
+              maintenanceMode: checkbox({ defaultValue: false }),
+            },
+            isSingleton: true,
+          },
+        },
+      }
+
+      const schema = generatePrismaSchema(config)
+
+      expect(schema).toContain('id        Int      @id @default(1)')
+      expect(schema).not.toContain('id        String   @id @default(cuid())')
+      expect(schema).toMatchSnapshot()
+    })
+
+    it('should generate regular model with String @id @default(cuid())', () => {
+      const config: OpenSaasConfig = {
+        db: {
+          provider: 'sqlite',
+        },
+        lists: {
+          Post: {
+            fields: {
+              title: text(),
+            },
+          },
+        },
+      }
+
+      const schema = generatePrismaSchema(config)
+
+      expect(schema).toContain('id        String   @id @default(cuid())')
+      expect(schema).not.toContain('id        Int      @id @default(1)')
+    })
   })
 })

packages/cli/src/generator/prisma.ts

@@ -429,8 +429,12 @@ export function generatePrismaSchema(config: OpenSaasConfig): string {
   for (const [listName, listConfig] of Object.entries(config.lists)) {
     lines.push(`model ${listName} {`)
 
-    // Always add id field
-    lines.push('  id        String   @id @default(cuid())')
+    // Add id field - singleton lists use Int @id (always 1) to match Keystone 6 behaviour
+    if (listConfig.isSingleton) {
+      lines.push('  id        Int      @id @default(1)')
+    } else {
+      lines.push('  id        String   @id @default(cuid())')
+    }
 
     // Track relationship fields for later processing
     const relationshipFields: Array<{

packages/cli/src/generator/types.ts

@@ -121,11 +121,16 @@ function generateTransformedFieldsType(
  * Generate TypeScript Output type for a model (includes virtual fields)
  * This is kept for backwards compatibility but CustomDB uses Prisma's GetPayload + VirtualFields
  */
-function generateModelOutputType(listName: string, fields: Record<string, FieldConfig>): string {
+function generateModelOutputType(
+  listName: string,
+  fields: Record<string, FieldConfig>,
+  isSingleton: boolean,
+): string {
   const lines: string[] = []
 
   lines.push(`export type ${listName}Output = {`)
-  lines.push('  id: string')
+  // Singleton lists use Int @id (always 1) matching Keystone 6 behaviour
+  lines.push(isSingleton ? '  id: number' : '  id: string')
 
   for (const [fieldName, fieldConfig] of Object.entries(fields)) {
     // Skip virtual fields - they're in VirtualFields type
@@ -993,7 +998,7 @@ export function generateTypes(config: OpenSaasConfig): string {
     // Generate TransformedFields type (needed by CustomDB)
     lines.push(generateTransformedFieldsType(listName, listConfig.fields))
     lines.push('')
-    lines.push(generateModelOutputType(listName, listConfig.fields))
+    lines.push(generateModelOutputType(listName, listConfig.fields, !!listConfig.isSingleton))
     lines.push('')
     lines.push(generateModelTypeAlias(listName))
     lines.push('')

packages/core/src/context/index.ts

@@ -893,8 +893,10 @@ function createCreate<TPrisma extends PrismaClientLike>(
     // Access Prisma model dynamically - required because model names are generated at runtime
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     const model = (prisma as any)[getDbKey(listName)]
+    // Singleton lists use Int @id with value always 1 (matching Keystone 6 behaviour)
+    const createData = isSingletonList(listConfig) ? { id: 1, ...data } : data
     const item = await model.create({
-      data,
+      data: createData,
     })
 
     // 9. Execute list-level afterOperation hook

packages/core/tests/singleton.test.ts

@@ -78,7 +78,7 @@ describe('Singleton Lists', () => {
     it('should allow creating the first record', async () => {
       mockPrisma.settings.count.mockResolvedValue(0)
       mockPrisma.settings.create.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'Test Site',
         maintenanceMode: false,
         maxUploadSize: 10,
@@ -146,7 +146,7 @@ describe('Singleton Lists', () => {
 
     it('should return existing record on get()', async () => {
       const mockSettings = {
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
@@ -168,7 +168,7 @@ describe('Singleton Lists', () => {
       mockPrisma.settings.findFirst.mockResolvedValue(null)
       mockPrisma.settings.count.mockResolvedValue(0)
       mockPrisma.settings.create.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
@@ -183,6 +183,7 @@ describe('Singleton Lists', () => {
       expect(result?.siteName).toBe('My Site')
       expect(mockPrisma.settings.create).toHaveBeenCalledWith({
         data: {
+          id: 1,
           siteName: 'My Site',
           maintenanceMode: false,
           maxUploadSize: 10,
@@ -207,26 +208,26 @@ describe('Singleton Lists', () => {
   describe('delete operation', () => {
     it('should block delete on singleton lists', async () => {
       mockPrisma.settings.findUnique.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
       })
 
       const context = getContext(config, mockPrisma, null)
 
-      await expect(context.db.settings.delete({ where: { id: '1' } })).rejects.toThrow(
+      await expect(context.db.settings.delete({ where: { id: 1 } })).rejects.toThrow(
         ValidationError,
       )
 
-      await expect(context.db.settings.delete({ where: { id: '1' } })).rejects.toThrow(
+      await expect(context.db.settings.delete({ where: { id: 1 } })).rejects.toThrow(
         'singleton list',
       )
     })
 
     it('should block delete even in sudo mode', async () => {
       mockPrisma.settings.findUnique.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
@@ -235,7 +236,7 @@ describe('Singleton Lists', () => {
       const context = getContext(config, mockPrisma, null)
       const sudoContext = context.sudo()
 
-      await expect(sudoContext.db.settings.delete({ where: { id: '1' } })).rejects.toThrow(
+      await expect(sudoContext.db.settings.delete({ where: { id: 1 } })).rejects.toThrow(
         ValidationError,
       )
     })
@@ -267,14 +268,14 @@ describe('Singleton Lists', () => {
   describe('update operation', () => {
     it('should allow updating the singleton record', async () => {
       mockPrisma.settings.findUnique.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
       })
 
       mockPrisma.settings.update.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'Updated Site',
         maintenanceMode: true,
         maxUploadSize: 20,
@@ -285,7 +286,7 @@ describe('Singleton Lists', () => {
       const context = getContext(config, mockPrisma, null)
 
       const result = await context.db.settings.update({
-        where: { id: '1' },
+        where: { id: 1 },
         data: { siteName: 'Updated Site', maintenanceMode: true, maxUploadSize: 20 },
       })
 
@@ -298,7 +299,7 @@ describe('Singleton Lists', () => {
   describe('findUnique operation', () => {
     it('should allow findUnique on singleton lists', async () => {
       mockPrisma.settings.findFirst.mockResolvedValue({
-        id: '1',
+        id: 1,
         siteName: 'My Site',
         maintenanceMode: false,
         maxUploadSize: 10,
@@ -307,7 +308,7 @@ describe('Singleton Lists', () => {
       })
 
       const context = getContext(config, mockPrisma, null)
-      const result = await context.db.settings.findUnique({ where: { id: '1' } })
+      const result = await context.db.settings.findUnique({ where: { id: 1 } })
 
       expect(result).toBeDefined()
       expect(result?.siteName).toBe('My Site')