README.md

Wallet Mock

Fully functional end-to-end (E2E) tests for your decentralized application (dApp). This package installs a fully operational, headless Web3 Wallet into the Playwright Browser Context. The wallet can be configured to execute on the blockchain or return mock responses. It is discoverable through EIP-6963 and leverages viem Account and Transport interfaces for easy customization.

Features

• Create comprehensive E2E tests for your dApps, including real blockchain transactions
• Mock specific calls or all calls to the wallet
• All wallet actions are pre-approved by default, eliminating the need for user interaction
• All wallet interactions are headless, meaning, no user interaction is required. You should be testing your dApp, not the wallet

Quickstart

Install

npm install -D @johanneskares/wallet-mock

Example

import { test } from "@playwright/test";
import { installMockWallet } from "@johanneskares/wallet-mock";
import { privateKeyToAccount } from "viem/accounts";
import { http } from "viem";
import { sepolia } from "viem/chains";

test.beforeEach(async ({ page }) => {
  await installMockWallet({
    page,
    account: privateKeyToAccount(
      "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
    ),
    defaultChain: sepolia,
    transports: { [sepolia.id]: http() },
  });
});

test("Your Test", async ({ page }) => {
  await page.getByRole("button", { name: "Log In" }).click();
  await page.getByRole("button", { name: "Choose Wallet" }).click();
  await page.getByRole("menuitem", { name: "Mock Wallet" }).click();
});

Note: This setup will execute actual transactions on the blockchain without user intervention using the provided Private Key.

Uniswap Demo

The Mock Wallet will show up as an EIP-6963 compatible wallet.

Mocking

Here's a simple example of how to mock a specific function while using regular RPC calls for all other functions:

await installMockWallet({
  page,
  account: privateKeyToAccount(
    "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
  ),
  defaultChain: sepolia,
  transports: {
    [sepolia.id]: (config) => {
      return custom({
        request: async ({ method, params }) => {
          // Mock only this RPC call
          if (method === "eth_sendTransaction") {
            return "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef";
          }

          return await http()(config).request({ method, params });
        },
      })(config);
    }
  },
});

Testing with Hardhat

To test with a local Hardhat node:

1. Start your local Hardhat Node:

   npx hardhat node

2. Connect the Mock Wallet to your Hardhat Node:

   import { hardhat } from "viem/chains";
   
   await installMockWallet({
     page,
     account: privateKeyToAccount(
       "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
     ),
     defaultChain: hardhat,
   });