refactor: load Prisma client via dynamic import() with path normalization

Ports upstream PR codepunkt#32 (codepunkt#32).
createContext becomes async and loads clientPath via await import() with
paths normalized so relative and absolute filesystem specifiers resolve
against process.cwd() and convert to file:// URLs, while bare specifiers
and existing file:// URLs pass through. Fixes Prisma 7 prisma-client
generator compatibility.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tywenk

src/context.test.ts

@@ -1,3 +1,5 @@
+import { resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import {
   type PrismaClient as PrismaClientStub,
@@ -19,9 +21,9 @@ const makeContext = async (
     | 'transactionPending'
     | 'transactionStarted'
     | 'transactionEnded' = 'transactionPending',
-): Promise<[ReturnType<typeof createContext>, PrismaClientStub]> => {
-  const context = createContext({
-    clientPath: '../test/prisma-client-stub.js',
+): Promise<[Awaited<ReturnType<typeof createContext>>, PrismaClientStub]> => {
+  const context = await createContext({
+    clientPath: './test/prisma-client-stub.js',
     databaseUrl: 'postgres://fake',
     log: ['query'],
     transactionOptions: { timeout: 123 },
@@ -53,6 +55,24 @@ describe('createContext', () => {
     await ctx.teardown();
   });
 
+  it('accepts an absolute file:// URL as clientPath', async () => {
+    vi.stubEnv('DATABASE_URL', 'postgres://fake');
+    const fileUrl = pathToFileURL(resolve('./test/prisma-client-stub.js')).href;
+    const ctx = await createContext({
+      clientPath: fileUrl,
+      databaseUrl: 'postgres://fake',
+      log: ['query'],
+      transactionOptions: { timeout: 123 },
+    });
+    await ctx.setup();
+
+    expect(PrismaPgMock).toHaveBeenCalledWith({
+      connectionString: 'postgres://fake',
+    });
+
+    await ctx.teardown();
+  });
+
   it('throws when client is accessed outside of a test transaction', async () => {
     const [transactionPendingContext] = await makeContext('transactionPending');
     const [transactionEndedContext] = await makeContext('transactionEnded');

src/context.ts

@@ -1,11 +1,15 @@
-import { createRequire } from 'node:module';
+import { isAbsolute, resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
 import { PrismaPg } from '@prisma/adapter-pg';
 import type {
   PrismaClientLike,
   PrismaEnvironmentOptions,
 } from './dts/index.js';
 
-const require = createRequire(import.meta.url);
+const resolveModuleSpecifier = (specifier: string): string => {
+  const isPathLike = specifier.startsWith('.') || isAbsolute(specifier);
+  return isPathLike ? pathToFileURL(resolve(specifier)).href : specifier;
+};
 
 /**
  * Creates the test context used by the `prisma` Vitest environment.
@@ -14,7 +18,7 @@ const require = createRequire(import.meta.url);
  * @returns The test context object used by both the Vitest environment and the
  * user's Prisma client mock.
  */
-export function createContext(options: PrismaEnvironmentOptions) {
+export async function createContext(options: PrismaEnvironmentOptions) {
   let savePointCounter = 0;
 
   /**
@@ -31,7 +35,9 @@ export function createContext(options: PrismaEnvironmentOptions) {
    */
   let internalEndTestTransaction: (() => void) | null = null;
 
-  const { PrismaClient } = require(options.clientPath);
+  const { PrismaClient } = await import(
+    resolveModuleSpecifier(options.clientPath)
+  );
   const originalClient: PrismaClientLike = new PrismaClient({
     adapter: new PrismaPg({ connectionString: process.env.DATABASE_URL }),
     log: options.log,

src/index.test.ts

@@ -24,7 +24,7 @@ import environment from '../src/index.js';
 describe('prisma environment', () => {
   const global: any = {};
   const options = {
-    clientPath: '../test/prisma-client-stub.js',
+    clientPath: './test/prisma-client-stub.js',
   };
 
   beforeEach(() => {

src/index.ts

@@ -16,7 +16,7 @@ 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.