Update readme

Create startBundler method to avoid needing shell args externally.
Make gasFactor, minStake, and minUnstakeDelay optional.

README.md

@@ -1,8 +1,73 @@
 # Test Bundler
 
+An EIP-4337 bundler used in MetaMask client E2E tests.
+
 > [!NOTE]
 > Forked from [eth-infinitism/bundler](https://github.com/eth-infinitism/bundler).
 
-An EIP-4337 bundler to be used in client E2E tests.
+## Usage
+
+### Start Server
+
+```typescript
+import { startBundler, BundlerServer } from '@metamask/test-bundler';
+
+const server = await startBundler({
+  configFile: './some-directory/bundler.config.json',
+  unsafe: true, // Disable extra validations requiring RPC debug methods.
+});
+```
+
+The server is accessible at `http://localhost:3000/rpc` by default.
+
+### Stop Server
+
+```typescript
+await server.stop();
+```
+
+## Configuration
+
+The server is primarily configured using a JSON file:
+
+```json
+{
+  // Delay in seconds before submitting any pending user operations in a transaction.
+  "autoBundleInterval": 3,
+  // Max number of user operations in a single transaction.
+  "autoBundleMempoolSize": 10,
+  // Account to be compensated for the gas cost of the transaction.
+  "beneficiary": "0x8890d2dAB1922Bec92922f7E6879D5c65ba333f4",
+  // Address of the entrypoint smart contract.
+  "entryPoint": "0x18b06605539dc02ecD3f7AB314e38eB7c1dA5c9b",
+  // Max total gas of user operations in a single transaction.
+  "maxBundleGas": 5e6,
+  // Minimum allowed balance of the signing account.
+  "minBalance": "0",
+  // Path to a text file containing the mnemonic for the account signing the transactions.
+  "mnemonic": "./test/e2e/bundler.mnemonic.txt",
+  // URL of an RPC provider for the desired network.
+  "network": "http://127.0.0.1:8545",
+  // Local port to run the server on.
+  "port": "3000"
+}
+```
+
+## Build
+
+```shell
+# Install dependencies.
+yarn
+
+# 1. Compile smart contracts using Hardhat.
+# 2. Compile typescript sources to `dist` folder.
+yarn setup
+```
+
+## Test
+
+Run the unit tests using Hardhat:
 
-Creates the bundler server at `http://localhost:3000/rpc` by default.
+```
+yarn test
+```

src/bundler/BundlerConfig.ts

@@ -28,7 +28,7 @@ export type BundlerConfig = {
 export const BundlerConfigShape = {
   beneficiary: ow.string,
   entryPoint: ow.string,
-  gasFactor: ow.string,
+  gasFactor: ow.optional.string,
   minBalance: ow.string,
   mnemonic: ow.string,
   network: ow.string,
@@ -40,8 +40,8 @@ export const BundlerConfigShape = {
   whitelist: ow.optional.array.ofType(ow.string),
   blacklist: ow.optional.array.ofType(ow.string),
   maxBundleGas: ow.number,
-  minStake: ow.string,
-  minUnstakeDelay: ow.number,
+  minStake: ow.optional.string,
+  minUnstakeDelay: ow.optional.number,
   autoBundleInterval: ow.number,
   autoBundleMempoolSize: ow.number,
 };

src/bundler/Config.ts

@@ -28,7 +28,7 @@ function getCommandLineParams(programOpts: any): Partial<BundlerConfig> {
  * @param sources
  */
 function mergeConfigs(...sources: Partial<BundlerConfig>[]): BundlerConfig {
-  const mergedConfig = Object.assign({}, ...sources);
+  const mergedConfig = Object.assign({}, ...sources) as BundlerConfig;
   ow(mergedConfig, ow.object.exactShape(BundlerConfigShape));
   return mergedConfig;
 }

src/bundler/runBundler.ts

@@ -43,6 +43,31 @@ export async function connectContracts(
   };
 }
 
+/**
+ * Start the bundler server.
+ * @param options - Options for the bundler server.
+ * @param options.configFile - Path to the config file.
+ * @param options.unsafe - Whether to disable additional validations requiring the RPC debug methods.
+ * @returns The bundler server instance.
+ */
+export async function startBundler({
+  configFile,
+  unsafe,
+}: {
+  configFile: string;
+  unsafe?: boolean;
+}): Promise<BundlerServer> {
+  const args = [
+    '-',
+    '-',
+    unsafe ? '--unsafe' : undefined,
+    '--config',
+    configFile,
+  ].filter((arg) => arg !== undefined) as string[];
+
+  return await runBundler(args);
+}
+
 /**
  * start the bundler server.
  * this is an async method, but only to resolve configuration. after it returns, the server is only active after asyncInit()

src/index.ts

@@ -1,2 +1,2 @@
-export { runBundler } from './bundler/runBundler';
+export { startBundler } from './bundler/runBundler';
 export { BundlerServer } from './bundler/BundlerServer';