Resolve clientPath against consuming project's CWD

Normalize relative and absolute filesystem clientPath values to file://
URLs before dynamic import so they resolve from the project root instead
of this module's install location. Bare specifiers and existing file://
URLs pass through unchanged. Adds a regression test covering the file://
URL path used by the Prisma 7 setup.

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

Author: tywenk

src/contest.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,
@@ -21,7 +23,7 @@ const makeContext = async (
     | 'transactionEnded' = 'transactionPending',
 ): Promise<[Awaited<ReturnType<typeof createContext>>, PrismaClientStub]> => {
   const context = await createContext({
-    clientPath: '../test/prisma-client-stub.js',
+    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

@@ -1,3 +1,5 @@
+import { isAbsolute, resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
 import { PrismaPg } from '@prisma/adapter-pg';
 import type {
   PrismaClientLike,
@@ -28,7 +30,17 @@ export async function createContext(options: PrismaPostgresEnvironmentOptions) {
    */
   let internalEndTestTransaction: (() => void) | null = null;
 
-  const { PrismaClient } = await import(options.clientPath);
+  // Normalize clientPath so relative/absolute filesystem paths resolve against
+  // the consuming project's CWD instead of this module's location. Leave bare
+  // module specifiers (e.g. '@prisma/client') and existing file:// URLs
+  // untouched so ESM resolution handles them as-is.
+  const isPathLike =
+    options.clientPath.startsWith('.') || isAbsolute(options.clientPath);
+  const clientImportPath = isPathLike
+    ? pathToFileURL(resolve(options.clientPath)).href
+    : options.clientPath;
+
+  const { PrismaClient } = await import(clientImportPath);
   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-postgres environment', () => {
   const global: any = {};
   const options = {
-    clientPath: '../test/prisma-client-stub.js',
+    clientPath: './test/prisma-client-stub.js',
   };
 
   beforeEach(() => {