fix(core): coerce calendarDay writes to Date before Prisma 7 validation

.changeset/tidy-plums-argue.md

@@ -0,0 +1,5 @@
+---
+'@opensaas/stack-core': patch
+---
+
+Fix `calendarDay` writes 500ing on Prisma 7 `@db.Date` columns — a `resolveInput` hook now coerces a `YYYY-MM-DD` string to a UTC-midnight `Date` before validation, and the field's zod schema accepts either shape.

packages/core/src/fields/calendar-day.test.ts

@@ -1,7 +1,9 @@
-import { describe, it, expect, expectTypeOf } from 'vitest'
+import { describe, it, expect, expectTypeOf, vi } from 'vitest'
 import { calendarDay } from './index.js'
 import { generateZodSchema, validateWithZod } from '../validation/schema.js'
+import { getContext } from '../context/index.js'
 import type { FieldConfig } from '../config/types.js'
+import type { OpenSaasConfig } from '../config/types.js'
 
 /**
  * calendarDay is a YYYY-MM-DD string end-to-end (Keystone's CalendarDay
@@ -54,7 +56,7 @@ describe('calendarDay field (YYYY-MM-DD string end-to-end)', () => {
     })
   })
 
-  describe('write validation (string-only)', () => {
+  describe('write validation (YYYY-MM-DD string, or a Date post-resolveInput)', () => {
     const fields: Record<string, FieldConfig> = {
       startsOn: calendarDay({ validation: { isRequired: true } }),
     }
@@ -73,15 +75,18 @@ describe('calendarDay field (YYYY-MM-DD string end-to-end)', () => {
       }
     })
 
-    it('rejects a Date instance at runtime (not a string)', () => {
-      // A typed caller cannot reach here (input type is `string`), but the
-      // validator is string-only as a runtime backstop.
+    it('accepts a Date instance (the shape resolveInput produces from a valid string)', () => {
+      // The write pipeline runs field `resolveInput` BEFORE this schema, and
+      // calendarDay's resolveInput turns a valid YYYY-MM-DD string into a UTC
+      // Date (see #621) so Prisma's `@db.Date` write validator accepts it. So
+      // by the time this schema runs, a successful write reaches it as a
+      // Date, not the original string — the schema must accept both shapes.
       const result = validateWithZod(
-        { startsOn: new Date('2025-01-15') } as unknown as Record<string, unknown>,
+        { startsOn: new Date('2025-01-15T00:00:00.000Z') } as unknown as Record<string, unknown>,
         fields,
         'create',
       )
-      expect(result.success).toBe(false)
+      expect(result.success).toBe(true)
     })
 
     it('zod schema for the field validates the YYYY-MM-DD shape', () => {
@@ -91,6 +96,62 @@ describe('calendarDay field (YYYY-MM-DD string end-to-end)', () => {
     })
   })
 
+  describe('write transform (resolveInput coerces YYYY-MM-DD string to a UTC Date, #621)', () => {
+    // The write pipeline calls fieldConfig.hooks.resolveInput({ resolvedData,
+    // fieldKey, ... }) BEFORE zod validation runs. We exercise that hook
+    // directly with the value shapes a caller (or an upstream list-level
+    // resolveInput) can produce.
+    function writeValue(value: unknown): unknown {
+      const field = calendarDay()
+      const hook = field.hooks?.resolveInput
+      if (!hook) throw new Error('calendarDay must define a resolveInput hook')
+      return (
+        hook as unknown as (args: {
+          resolvedData: Record<string, unknown>
+          fieldKey: string
+        }) => unknown
+      )({ resolvedData: { startsOn: value }, fieldKey: 'startsOn' })
+    }
+
+    it('converts a YYYY-MM-DD string to a UTC-midnight Date', () => {
+      const result = writeValue('2025-01-15') as Date
+      expect(result).toBeInstanceOf(Date)
+      expect(result.toISOString()).toBe('2025-01-15T00:00:00.000Z')
+    })
+
+    it('passes an already-Date value through unchanged', () => {
+      const date = new Date('2025-06-01T00:00:00.000Z')
+      expect(writeValue(date)).toBe(date)
+    })
+
+    it('passes null/undefined through unchanged (so isRequired can still reject a missing value)', () => {
+      expect(writeValue(null)).toBeNull()
+      expect(writeValue(undefined)).toBeUndefined()
+    })
+
+    it('leaves a malformed string untouched so zod still rejects it with a clear message', () => {
+      expect(writeValue('15/01/2025')).toBe('15/01/2025')
+    })
+
+    it('reads resolvedData[fieldKey], not inputData — survives a list-level resolveInput default', () => {
+      // A list-level resolveInput can inject a default for an omitted key
+      // into resolvedData before field resolveInput runs. Reading
+      // resolvedData (not the original inputData) here means that injected
+      // default is what gets coerced, instead of being read as `undefined`
+      // and overwriting the injected default with null.
+      const field = calendarDay()
+      const hook = field.hooks?.resolveInput as unknown as (args: {
+        resolvedData: Record<string, unknown>
+        fieldKey: string
+      }) => unknown
+      const result = hook({
+        resolvedData: { startsOn: '2025-03-20' }, // injected by a list-level hook
+        fieldKey: 'startsOn',
+      }) as Date
+      expect(result.toISOString()).toBe('2025-03-20T00:00:00.000Z')
+    })
+  })
+
   describe('read transform (resolveOutput returns a YYYY-MM-DD string)', () => {
     // The read pipeline calls fieldConfig.hooks.resolveOutput({ value, ... }).
     // We exercise that hook directly with the value shapes Prisma can return.
@@ -137,4 +198,94 @@ describe('calendarDay field (YYYY-MM-DD string end-to-end)', () => {
       expect(hook({ value: '2025-01-15' })).toBe('custom:2025-01-15')
     })
   })
+
+  describe('end-to-end via context.db.*.create/update (#621 repro)', () => {
+    // Prisma 7's client validator rejects a bare YYYY-MM-DD string for a
+    // `@db.Date` column. Assert the value actually forwarded to the Prisma
+    // client is a Date, not the string the caller passed in.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any -- mock Prisma client
+    let mockPrisma: any
+
+    function buildConfig(): OpenSaasConfig {
+      mockPrisma = {
+        event: {
+          findFirst: vi.fn(),
+          findUnique: vi.fn(),
+          findMany: vi.fn(),
+          create: vi.fn(),
+          update: vi.fn(),
+          delete: vi.fn(),
+          count: vi.fn(),
+        },
+      }
+      return {
+        db: {
+          provider: 'postgresql',
+          prismaClientConstructor: (PrismaClient) => new PrismaClient(),
+        },
+        lists: {
+          Event: {
+            fields: {
+              startsOn: calendarDay({ validation: { isRequired: true } }),
+            },
+            access: {
+              operation: {
+                query: () => true,
+                create: () => true,
+                update: () => true,
+                delete: () => true,
+              },
+            },
+          },
+        },
+      }
+    }
+
+    it('create: a YYYY-MM-DD string reaches Prisma as a UTC-midnight Date', async () => {
+      const config = buildConfig()
+      mockPrisma.event.create.mockResolvedValue({
+        id: '1',
+        startsOn: new Date('2025-01-15T00:00:00.000Z'),
+      })
+      const context = await getContext(config, mockPrisma, null)
+
+      await context.db.event.create({ data: { startsOn: '2025-01-15' } })
+
+      expect(mockPrisma.event.create).toHaveBeenCalledTimes(1)
+      const callArgs = mockPrisma.event.create.mock.calls[0][0]
+      expect(callArgs.data.startsOn).toBeInstanceOf(Date)
+      expect((callArgs.data.startsOn as Date).toISOString()).toBe('2025-01-15T00:00:00.000Z')
+    })
+
+    it('update: a YYYY-MM-DD string reaches Prisma as a UTC-midnight Date', async () => {
+      const config = buildConfig()
+      const existing = { id: '1', startsOn: new Date('2025-01-15T00:00:00.000Z') }
+      mockPrisma.event.findUnique.mockResolvedValue(existing)
+      mockPrisma.event.update.mockResolvedValue({
+        ...existing,
+        startsOn: new Date('2025-02-20T00:00:00.000Z'),
+      })
+      const context = await getContext(config, mockPrisma, null)
+
+      await context.db.event.update({ where: { id: '1' }, data: { startsOn: '2025-02-20' } })
+
+      expect(mockPrisma.event.update).toHaveBeenCalledTimes(1)
+      const callArgs = mockPrisma.event.update.mock.calls[0][0]
+      expect(callArgs.data.startsOn).toBeInstanceOf(Date)
+      expect((callArgs.data.startsOn as Date).toISOString()).toBe('2025-02-20T00:00:00.000Z')
+    })
+
+    it('the read result is still normalised back to a YYYY-MM-DD string', async () => {
+      const config = buildConfig()
+      mockPrisma.event.create.mockResolvedValue({
+        id: '1',
+        startsOn: new Date('2025-01-15T00:00:00.000Z'),
+      })
+      const context = await getContext(config, mockPrisma, null)
+
+      const result = await context.db.event.create({ data: { startsOn: '2025-01-15' } })
+
+      expect(result?.startsOn).toBe('2025-01-15')
+    })
+  })
 })

packages/core/src/fields/index.ts

@@ -523,9 +523,13 @@ export function timestamp<
  * - Stores date values only (no time component)
  * - PostgreSQL/MySQL: Uses native DATE type via @db.Date
  * - SQLite: Uses String representation
- * - **Writes:** accept only a `YYYY-MM-DD` string; a malformed string or a
- *   `Date` is rejected at runtime by validation (a `ValidationError`). Genuine
- *   compile-time rejection at the `context.db` call site is tracked in #599.
+ * - **Writes:** pass a `YYYY-MM-DD` string (the declared type). A
+ *   `resolveInput` hook converts a valid string to a UTC-midnight `Date`
+ *   before validation, since Prisma 7's client validator rejects a bare date
+ *   string for a `@db.Date` column (#621); a `Date` is also accepted
+ *   directly. A malformed string is rejected at runtime by validation (a
+ *   `ValidationError`). Genuine compile-time rejection of a `Date` at the
+ *   `context.db` call site is tracked in #599.
  * - **Reads:** always return a `YYYY-MM-DD` string. Even though the underlying
  *   `@db.Date` column hands Prisma a `Date`, a `resolveOutput` transform
  *   normalises it back to a `YYYY-MM-DD` string so the runtime value matches
@@ -573,13 +577,33 @@ export function calendarDay<
   return {
     type: 'calendarDay',
     ...options,
+    // Writes: the write pipeline runs field resolveInput BEFORE zod
+    // validation (Hook Pipeline: field resolveInput → built-in field rules),
+    // so this is the only point a YYYY-MM-DD string can be turned into
+    // something Prisma's `@db.Date` write validator accepts — Prisma 7
+    // rejects a bare date string there (#621). Convert a valid string to a
+    // UTC-midnight Date; leave anything else (a Date already, null/undefined,
+    // or a malformed string) untouched so the zod schema below still rejects
+    // malformed input with a clear message. Reads resolvedData[fieldKey]
+    // (not raw inputData) so a list-level resolveInput that injects a default
+    // for an omitted key is still coerced instead of being overwritten.
+    //
     // Reads: the underlying @db.Date column hands Prisma a Date (or a TEXT
     // string under the SQLite fallback). Normalise to a YYYY-MM-DD string so the
     // runtime value matches the declared `string` type. UTC components are used
     // so the formatting never drifts a day in non-UTC timezones.
     // Cast hooks to any since field builders are generic and can't know the
     // specific TFieldKey (same pattern as password()).
     hooks: {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any -- Field builder hooks must be generic
+      resolveInput: ({ resolvedData, fieldKey }: { resolvedData: any; fieldKey: string }) => {
+        const value = resolvedData?.[fieldKey]
+        if (value == null || value instanceof Date) return value
+        if (typeof value === 'string' && /^\d{4}-\d{2}-\d{2}$/.test(value)) {
+          return new Date(`${value}T00:00:00.000Z`)
+        }
+        return value
+      },
       // eslint-disable-next-line @typescript-eslint/no-explicit-any -- Field builder hooks must be generic
       resolveOutput: ({ value }: { value: any }) => formatCalendarDay(value),
       // Merge with user-provided hooks if any
@@ -590,15 +614,19 @@ export function calendarDay<
       const validation = options?.validation
       const isRequired = validation?.isRequired
 
-      // Accept ISO8601 date strings (YYYY-MM-DD)
-      const baseSchema = z.string({
-        message: `${formatFieldName(fieldName)} must be a valid date in ISO8601 format (YYYY-MM-DD)`,
-      })
+      // Accept ISO8601 date strings (YYYY-MM-DD) in the shape a caller passes,
+      // or a `Date` — the shape resolveInput above turns a valid string into
+      // before this schema runs. Malformed strings fall through resolveInput
+      // untouched and still fail the regex here with a clear message.
+      const stringSchema = z
+        .string({
+          message: `${formatFieldName(fieldName)} must be a valid date in ISO8601 format (YYYY-MM-DD)`,
+        })
+        .regex(/^\d{4}-\d{2}-\d{2}$/, {
+          message: `${formatFieldName(fieldName)} must be in YYYY-MM-DD format`,
+        })
 
-      // Validate ISO8601 date format (YYYY-MM-DD)
-      const dateSchema = baseSchema.regex(/^\d{4}-\d{2}-\d{2}$/, {
-        message: `${formatFieldName(fieldName)} must be in YYYY-MM-DD format`,
-      })
+      const dateSchema = z.union([stringSchema, z.date()])
 
       if (isRequired && operation === 'create') {
         return dateSchema