Typings Improved

Author: prageeth

src/__tests__/index.test.ts

@@ -1,13 +1,30 @@
 import { jest } from "@jest/globals";
 
 import { PrismaClient } from "@prisma/client";
-import { createPrefixedIdsExtension, extendPrismaClient } from "../index";
+import {
+  createPrefixedIdsExtension,
+  extendPrismaClient,
+  PrefixConfig,
+} from "../index";
+
+type MockUser = {
+  id: string;
+  name: string;
+};
+
+type CreateArgs = {
+  data: Record<string, unknown>;
+};
 
 // Mock PrismaClient
 jest.mock("@prisma/client", () => {
   return {
     PrismaClient: jest.fn().mockImplementation(() => ({
       $extends: jest.fn(),
+      user: {
+        create: jest.fn(),
+        findUnique: jest.fn(),
+      },
     })),
   };
 });
@@ -18,12 +35,12 @@ jest.mock("nanoid", () => ({
 }));
 
 describe("PrefixedIdsExtension", () => {
-  let prisma: PrismaClient;
+  let prisma: jest.Mocked<PrismaClient>;
   const mockQuery = jest.fn((args: any) => Promise.resolve(args));
 
   beforeEach(() => {
     jest.clearAllMocks();
-    prisma = new PrismaClient();
+    prisma = new PrismaClient() as jest.Mocked<PrismaClient>;
   });
 
   describe("createPrefixedIdsExtension", () => {
@@ -115,6 +132,36 @@ describe("PrefixedIdsExtension", () => {
       expect(result.data[0]).toHaveProperty("id");
       expect(result.data[1]).toHaveProperty("id");
     });
+
+    it("should generate IDs with uppercase letters", async (): Promise<void> => {
+      const prefixConfig: PrefixConfig<"User"> = {
+        prefixes: {
+          User: "usr",
+        },
+        // Force an ID with uppercase for testing
+        idGenerator: (prefix: string): string => {
+          return `${prefix}_ABC123DEF`;
+        },
+      };
+
+      const extension = createPrefixedIdsExtension(prefixConfig);
+      prisma.$extends(extension);
+
+      // Mock the create operation
+      prisma.user.create.mockResolvedValueOnce({
+        id: "usr_ABC123DEF",
+        name: "Test User",
+      });
+
+      const user = await prisma.user.create({
+        data: {
+          name: "Test User",
+        },
+      });
+
+      // Test that the ID matches our pattern including uppercase
+      expect(user.id).toMatch(/^usr_[A-Z0-9]+$/);
+    });
   });
 
   describe("extendPrismaClient", () => {

src/index.ts

@@ -5,12 +5,15 @@ import { customAlphabet } from "nanoid";
 type ModelName = string;
 
 export type PrefixConfig<ModelName extends string> = {
-  prefixes: Record<ModelName, string>;
+  prefixes: Partial<Record<ModelName, string>>;
   idGenerator?: (prefix: string) => string;
 };
 
 const defaultIdGenerator = (prefix: string): string => {
-  const nanoid = customAlphabet("0123456789abcdefghijklmnopqrstuvwxyz", 24);
+  const nanoid = customAlphabet(
+    "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ",
+    24,
+  );
   return `${prefix}_${nanoid()}`;
 };
 
@@ -35,7 +38,7 @@ export function createPrefixedIdsExtension<ModelName extends string>(
 
   const prefixedId = (modelName: ModelName): string | null => {
     if (modelName in prefixes) {
-      return idGenerator(prefixes[modelName]);
+      return idGenerator(prefixes[modelName] as string);
     }
     return null;
   };