Use dynamic import() to load Prisma client

The previous implementation used createRequire(import.meta.url) to
synchronously require() the Prisma client at options.clientPath.

This is incompatible with Prisma 7's `prisma-client` generator, which
outputs plain TypeScript (ESM) files that cannot be loaded by Node's
native CJS require().

Switch to await import(options.clientPath) so that:

- Under Vitest, clientPath can point at the generated TS source
  directly (e.g. a file:// URL to `client.ts`), and Vite's transform
  pipeline handles the TypeScript/ESM resolution.
- Under plain Node, any ESM-compatible specifier continues to work
  (package names, file:// URLs, .js/.mjs paths).

`createContext` becomes async; callers must `await` it. The only
caller is `environment.setup`, which is already async.

Fixes #22

Author: tywenk

src/contest.test.ts

@@ -19,8 +19,8 @@ const makeContext = async (
     | 'transactionPending'
     | 'transactionStarted'
     | 'transactionEnded' = 'transactionPending',
-): Promise<[ReturnType<typeof createContext>, PrismaClientStub]> => {
-  const context = createContext({
+): Promise<[Awaited<ReturnType<typeof createContext>>, PrismaClientStub]> => {
+  const context = await createContext({
     clientPath: '../test/prisma-client-stub.js',
     databaseUrl: 'postgres://fake',
     log: ['query'],

src/context.ts

@@ -1,20 +1,17 @@
-import { createRequire } from 'node:module';
 import { PrismaPg } from '@prisma/adapter-pg';
 import type {
   PrismaClientLike,
   PrismaPostgresEnvironmentOptions,
 } from './dts/index.js';
 
-const require = createRequire(import.meta.url);
-
 /**
  * Creates the test context used by the `prisma-postgres` Vitest environment.
  *
  * @param options PrismaPostgresEnvironmentOptions
  * @returns The test context object used by both the Vitest environment and the
  * user's Prisma client mock.
  */
-export function createContext(options: PrismaPostgresEnvironmentOptions) {
+export async function createContext(options: PrismaPostgresEnvironmentOptions) {
   let savePointCounter = 0;
 
   /**
@@ -31,7 +28,7 @@ export function createContext(options: PrismaPostgresEnvironmentOptions) {
    */
   let internalEndTestTransaction: (() => void) | null = null;
 
-  const { PrismaClient } = require(options.clientPath);
+  const { PrismaClient } = await import(options.clientPath);
   const originalClient: PrismaClientLike = new PrismaClient({
     adapter: new PrismaPg({ connectionString: process.env.DATABASE_URL }),
     log: options.log,

src/index.ts

@@ -17,7 +17,7 @@ const environment: Environment = {
       throw new Error('no DATABASE_URL defined!');
     }
 
-    const ctx = createContext(options);
+    const ctx = await createContext(options);
     await ctx.setup();
 
     // make context available globally for setupFiles.