fix: add JsonValue short-circuit to prevent TS2589 on recursive type fields

JsonValue is a recursive type that causes TypeScript to hit depth limits
when ExtractInsertType/ExtractUpdateType/StripKyselyWrapper try to evaluate
conditional checks. Adding a JsonValue guard before the `extends` check
avoids expanding the recursive type entirely.

Also fixes pre-existing exactOptionalPropertyTypes error in dmmf-mocks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: samuelho-dev

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## 5.3.3
+
+### Patch Changes
+
+- Fix TS2589 "Type instantiation is excessively deep" for schemas with JsonValue fields
+
+  Added short-circuit guards in `ExtractInsertType`, `ExtractUpdateType`, and `StripKyselyWrapper` type utilities to avoid expanding the recursive `JsonValue` type before evaluating conditional type checks. This fixes the TS2589 error when using `Selectable<T>`, `Insertable<T>`, or `Updateable<T>` on schemas containing `JsonValue | null` fields (e.g., Prisma `Json?` columns).
+
 ## 5.3.2
 
 ### Patch Changes

package.json

@@ -1,6 +1,6 @@
 {
   "name": "prisma-effect-kysely",
-  "version": "5.3.2",
+  "version": "5.3.3",
   "description": "Prisma generator that creates Effect Schema types from Prisma schema compatible with Kysely",
   "license": "MIT",
   "author": "Samuel Ho",

src/__tests__/deep-type-instantiation.test.ts

@@ -32,7 +32,16 @@ import type {
   UpdateQueryBuilder,
 } from 'kysely';
 import { describe, it, expectTypeOf } from 'vitest';
-import { columnType, generated, type ColumnType, type Generated } from '../kysely/helpers';
+import {
+  columnType,
+  generated,
+  JsonValue,
+  type ColumnType,
+  type Generated,
+  type Selectable,
+  type Insertable,
+  type Updateable,
+} from '../kysely/helpers';
 
 // ============================================================================
 // Simulate a realistically complex database schema (20+ fields per table)
@@ -290,3 +299,85 @@ describe('Deep type instantiation - multiple tables simultaneously', () => {
     expectTypeOf<AllSelectables>().toHaveProperty('payment');
   });
 });
+
+// ============================================================================
+// JsonValue field tests - TS2589 regression prevention
+// ============================================================================
+// JsonValue is a recursive type. Without short-circuit guards in
+// ExtractInsertType / ExtractUpdateType / StripKyselyWrapper,
+// TypeScript tries to fully expand the recursive type before evaluating
+// the conditional — hitting the depth limit.
+
+const PaymentWithJson = Schema.Struct({
+  id: columnType(PaymentId, Schema.Never, Schema.Never),
+  order_id: OrderId,
+  amount: Schema.Number,
+  currency: Schema.String,
+  status: generated(Schema.String),
+  last_payment_error: Schema.NullOr(JsonValue),
+  metadata: Schema.NullOr(JsonValue),
+  raw_response: JsonValue,
+  created_at: generated(Schema.DateFromSelf),
+  updated_at: generated(Schema.DateFromSelf),
+});
+
+interface JsonTestDB {
+  payment_with_json: Schema.Schema.Type<typeof PaymentWithJson>;
+}
+
+describe('Deep type instantiation - JsonValue fields (TS2589 regression)', () => {
+  it('should resolve Selectable<PaymentWithJson> without TS2589', () => {
+    type Select = Selectable<typeof PaymentWithJson>;
+
+    expectTypeOf<Select>().toHaveProperty('id');
+    expectTypeOf<Select>().toHaveProperty('order_id');
+    expectTypeOf<Select>().toHaveProperty('last_payment_error');
+    expectTypeOf<Select>().toHaveProperty('metadata');
+    expectTypeOf<Select>().toHaveProperty('raw_response');
+  });
+
+  it('should resolve Insertable<PaymentWithJson> without TS2589', () => {
+    type Insert = Insertable<typeof PaymentWithJson>;
+
+    // id should be excluded (never insert)
+    expectTypeOf<Insert>().not.toHaveProperty('id');
+
+    // order_id should be required
+    expectTypeOf<Insert>().toHaveProperty('order_id');
+
+    // JsonValue fields should be present
+    expectTypeOf<Insert>().toHaveProperty('last_payment_error');
+    expectTypeOf<Insert>().toHaveProperty('metadata');
+    expectTypeOf<Insert>().toHaveProperty('raw_response');
+  });
+
+  it('should resolve Updateable<PaymentWithJson> without TS2589', () => {
+    type Update = Updateable<typeof PaymentWithJson>;
+
+    // id should be excluded (never update)
+    expectTypeOf<Update>().not.toHaveProperty('id');
+
+    // JsonValue fields should be present
+    expectTypeOf<Update>().toHaveProperty('last_payment_error');
+    expectTypeOf<Update>().toHaveProperty('metadata');
+    expectTypeOf<Update>().toHaveProperty('raw_response');
+  });
+
+  it('should resolve KyselySelectable with JsonValue fields without TS2589', () => {
+    type Select = KyselySelectable<JsonTestDB['payment_with_json']>;
+
+    expectTypeOf<Select>().toHaveProperty('id');
+    expectTypeOf<Select>().toHaveProperty('last_payment_error');
+    expectTypeOf<Select>().toHaveProperty('metadata');
+    expectTypeOf<Select>().toHaveProperty('raw_response');
+  });
+
+  it('should resolve KyselyInsertable with JsonValue fields without TS2589', () => {
+    type Insert = KyselyInsertable<JsonTestDB['payment_with_json']>;
+
+    expectTypeOf<Insert>().not.toHaveProperty('id');
+    expectTypeOf<Insert>().toHaveProperty('order_id');
+    expectTypeOf<Insert>().toHaveProperty('last_payment_error');
+    expectTypeOf<Insert>().toHaveProperty('raw_response');
+  });
+});

src/__tests__/helpers/dmmf-mocks.ts

@@ -84,20 +84,18 @@ export function createMockModel(overrides: Partial<DMMF.Model> & { name: string
  */
 export function createMockField(overrides: Partial<DMMF.Field> & { name: string }): DMMF.Field {
   return {
-    name: overrides.name,
-    kind: overrides.kind ?? 'scalar',
-    type: overrides.type ?? 'String',
-    isList: overrides.isList ?? false,
-    isRequired: overrides.isRequired ?? true,
-    isUnique: overrides.isUnique ?? false,
-    isId: overrides.isId ?? false,
-    isReadOnly: overrides.isReadOnly ?? false,
-    hasDefaultValue: overrides.hasDefaultValue ?? false,
-    relationName: overrides.relationName,
-    documentation: overrides.documentation,
-    nativeType: overrides.nativeType,
-    dbName: overrides.dbName ?? null,
-    isGenerated: overrides.isGenerated ?? false,
-    isUpdatedAt: overrides.isUpdatedAt ?? false,
+    kind: 'scalar',
+    type: 'String',
+    isList: false,
+    isRequired: true,
+    isUnique: false,
+    isId: false,
+    isReadOnly: false,
+    hasDefaultValue: false,
+    nativeType: null,
+    dbName: null,
+    isGenerated: false,
+    isUpdatedAt: false,
+    ...overrides,
   };
 }

src/kysely/helpers.ts

@@ -457,7 +457,11 @@ const extractParametersFromTypeLiteral = (
  * with unique symbols, which can cause type matching failures when TypeScript
  * compiles from source files with different symbol references.
  */
-type ExtractInsertType<T> = T extends { readonly __insert__: infer I } ? I : T;
+type ExtractInsertType<T> = T extends JsonValue
+  ? T
+  : T extends { readonly __insert__: infer I }
+    ? I
+    : T;
 
 /**
  * Check if a type is nullable (includes null or undefined).
@@ -487,7 +491,11 @@ type ExtractInsertBaseType<T> = ExtractInsertType<T>;
  * with unique symbols, which can cause type matching failures when TypeScript
  * compiles from source files with different symbol references.
  */
-type ExtractUpdateType<T> = T extends { readonly __update__: infer U } ? U : T;
+type ExtractUpdateType<T> = T extends JsonValue
+  ? T
+  : T extends { readonly __update__: infer U }
+    ? U
+    : T;
 
 /**
  * Custom Insertable type that:
@@ -553,7 +561,9 @@ type StripColumnTypeWrapper<T> = T extends {
  * Order matters: check Generated first, then ColumnType.
  * Preserves branded foreign keys (UserId, ProductId, etc.).
  */
-type StripKyselyWrapper<T> = StripColumnTypeWrapper<StripGeneratedWrapper<T>>;
+type StripKyselyWrapper<T> = T extends JsonValue
+  ? T
+  : StripColumnTypeWrapper<StripGeneratedWrapper<T>>;
 
 /**
  * Strip Kysely wrappers from all fields in a type.