System requirements

Problem

You see the following error when you try type-checking a project after you run prisma generate.

$./node_modules/.prisma/client/index.d.ts:10:33
$Type error: Type expected.
$   8 | export type PrismaPromise<A> = Promise<A> & {[prisma]: true}
$   9 | type UnwrapTuple<Tuple extends readonly unknown[]> = {
$> 10 |   [K in keyof Tuple]: K extends `${number}` ? Tuple[K] extends PrismaPromise<infer X> ? X : never : never
$     |                                 ^
$  11 | };
$  12 |
$  13 |

Solution

Upgrade your project to TypeScript 4.1.X or later. npm install -D typescript.

Problem

You see the following console error when you attempt to run an app that uses the groupBy feature:

$server.ts:6:25 - error TS2615: Type of property 'OR' circularly references itself in mapped type '{ [K in keyof { AND?: Enumerable<ProductScalarWhereWithAggregatesInput>; OR?: Enumerable<ProductScalarWhereWithAggregatesInput>; ... 4 more ...; category?: string | StringWithAggregatesFilter; }]: Or<...> extends 1 ? { ...; }[K] extends infer TK ? GetHavingFields<...> : never : {} extends FieldPaths<...> ? never : K...'.
$6   const grouped = await prisma.product.groupBy({
$                          ~~~~~~~~~~~~~~~~~~~~~~~~
$7     by: ['category']
$  ~~~~~~~~~~~~~~~~~~~~
$8   });
$  ~~~~
$server.ts:6:48 - error TS2554: Expected 0 arguments, but got 1.
$6   const grouped = await prisma.product.groupBy({
$                                                 ~
$7     by: ['category']
$  ~~~~~~~~~~~~~~~~~~~~
$8   });
$  ~~~

Solution

Upgrade your project to TypeScript 4.1.X or later. npm install -D typescript.