feat: add option to attach anvil logs to playwright report

packages/test/src/anvil.ts

@@ -248,6 +248,21 @@ export interface AnvilArgs {
   transactionBlockKeeper?: number | undefined;
 }
 
+export interface AnvilProcessCallbacks {
+  /**
+   * Called when a message is received from the Anvil process.
+   */
+  onMessage?: (message: string) => void;
+  /**
+   * Called when an error is received from the Anvil process.
+   */
+  onError?: (message: string) => void;
+  /**
+   * Called when the Anvil process is closed.
+   */
+  onClose?: (message: string) => void;
+}
+
 /**
  * Converts an object of options to an array of command line arguments.
  *
@@ -302,6 +317,7 @@ let workerInstances = 0;
 export const spawnAnvil = async (
   args: AnvilArgs,
   index = workerInstances++,
+  callbacks?: AnvilProcessCallbacks,
 ): Promise<{
   rpcUrl: `http://localhost:${number}`;
   stop: () => boolean;
@@ -316,6 +332,7 @@ export const spawnAnvil = async (
     subprocess.stdout.on("data", (data) => {
       const message = `[port ${port}] ${data.toString()}`;
 
+      callbacks?.onMessage?.(message);
       // console.debug(message);
 
       if (message.includes("Listening on")) {
@@ -327,9 +344,17 @@ export const spawnAnvil = async (
     subprocess.stderr.on("data", (data) => {
       const message = `[port ${port}] ${data.toString()}`;
 
+      callbacks?.onError?.(message);
+
       if (!started) reject(message);
       else console.warn(message);
     });
+
+    subprocess.on("close", (code) => {
+      const message = `[port ${port}] Anvil exited with code ${code}`;
+
+      callbacks?.onClose?.(message);
+    });
   });
 
   return {

packages/test/src/playwright.ts

@@ -1,4 +1,4 @@
-import { test } from "@playwright/test";
+import { type TestInfo, test } from "@playwright/test";
 import { http, type Chain, formatUnits } from "viem";
 import { type AnvilArgs, spawnAnvil } from "./anvil";
 import { type AnvilTestClient, createAnvilTestClient } from "./client";
@@ -7,9 +7,40 @@ export interface PlaywrightTestContext<chain extends Chain = Chain> {
   client: AnvilTestClient<chain>;
 }
 
+const attachLogToPlaywright = (testInfo: TestInfo) => {
+  const anvilLogs: string[] = [];
+
+  const attachLog = (message: string) => {
+    anvilLogs.push(message);
+  };
+
+  const onClose = (message: string) => {
+    attachLog(message);
+
+    testInfo.attach("Anvil Logs", {
+      body: anvilLogs.join("\n"),
+      contentType: "text/plain",
+    });
+  };
+
+  return {
+    onMessage: attachLog,
+    onError: attachLog,
+    onClose: onClose,
+  };
+};
+
+/**
+ * Creates a Playwright test that spawns an Anvil instance and injects a test client.
+ *
+ * @param chain - The chain to use.
+ * @param parameters - The parameters to pass to the Anvil instance.
+ * @param attachedAnvilLogs - Whether to attach the Anvil logs to the test that can be seen in the Playwright report (attachments tabs).
+ */
 export const createViemTest = <chain extends Chain>(
   chain: chain,
   parameters: AnvilArgs = {},
+  attachAnvilLogs = false,
 ) => {
   parameters.forkChainId ??= chain?.id;
   parameters.forkUrl ??= chain?.rpcUrls.default.http[0];
@@ -22,10 +53,11 @@ export const createViemTest = <chain extends Chain>(
 
   return test.extend<PlaywrightTestContext<chain>>({
     // biome-ignore lint/correctness/noEmptyPattern: required by playwright at runtime
-    client: async ({}, use) => {
+    client: async ({}, use, testInfo) => {
       const { rpcUrl, stop } = await spawnAnvil(
         parameters,
         test.info().workerIndex,
+        attachAnvilLogs ? attachLogToPlaywright(testInfo) : undefined,
       );
 
       const client = createAnvilTestClient(http(rpcUrl), chain);