fix: strip ANSI escape codes from wrangler log files (#10209)

* fix: strip ANSI escape codes from wrangler log files

- Modified appendToDebugLogFile to use stripAnsi() before writing to log files
- Added comprehensive tests for ANSI stripping functionality
- Log files will now be clean and readable without color escape sequences
- Console output still retains colors as expected
- Fixes issue #4492

Co-Authored-By: [email protected] <[email protected]>

* test: update log-file tests to use runInTempDir() instead of mocking filesystem

- Remove complex mocking approach for debugLogFilepath
- Import debugLogFilepath directly and use real filesystem operations
- Add better error handling in getLogFileContent() helper
- Tests now verify actual log file creation and ANSI stripping with real files
- All tests pass with runInTempDir() providing isolated test environments

Co-Authored-By: [email protected] <[email protected]>

* chore: add changeset for ANSI stripping feature

Co-Authored-By: [email protected] <[email protected]>

* test: use mockConsoleMethods() instead of logger mocking in log-file tests

- Remove vi.mock() for logger and unused mockConsoleMethods import
- Focus on testing core ANSI stripping functionality with real filesystem operations
- All tests now pass locally with proper runInTempDir() usage

Co-Authored-By: [email protected] <[email protected]>

* test: remove unused afterEach import from log-file tests

- Clean up test file after removing logger mocking
- All tests pass locally with proper runInTempDir() usage
- Formatting and linting checks pass

Co-Authored-By: [email protected] <[email protected]>

* fix: remove duplicate changeset file

- Remove .changeset/weak-chicken-fetch.md as it duplicates .changeset/smooth-shirts-add.md
- Both files had identical content for ANSI stripping feature
- Addresses GitHub PR comment about duplicate changeset

Co-Authored-By: [email protected] <[email protected]>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: [email protected] <[email protected]>

Author: devin-ai-integration[bot]

.changeset/smooth-shirts-add.md

@@ -0,0 +1,5 @@
+---
+"wrangler": patch
+---
+
+fix: strip ANSI escape codes from log files to improve readability and parsing

packages/wrangler/src/__tests__/utils/log-file.test.ts

@@ -0,0 +1,114 @@
+import { existsSync, readdirSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { appendToDebugLogFile, debugLogFilepath } from "../../utils/log-file";
+import { runInTempDir } from "../helpers/run-in-tmp";
+
+describe("appendToDebugLogFile", () => {
+	runInTempDir();
+
+	beforeEach(() => {
+		vi.stubEnv("WRANGLER_LOG_PATH", "logs");
+	});
+
+	function getLogFileContent(): string {
+		if (existsSync(debugLogFilepath)) {
+			return readFileSync(debugLogFilepath, "utf8");
+		}
+
+		if (existsSync("logs")) {
+			const logFiles = readdirSync("logs");
+			expect(logFiles.length).toBeGreaterThan(0);
+
+			const logFilePath = join("logs", logFiles[0]);
+			return readFileSync(logFilePath, "utf8");
+		}
+
+		throw new Error(
+			`No log files found. debugLogFilepath: ${debugLogFilepath}, logs dir exists: ${existsSync("logs")}`
+		);
+	}
+
+	it("should strip ANSI escape codes from error messages", async () => {
+		const messageWithAnsi = "\u001b[31mError: Something went wrong\u001b[0m";
+		const expectedCleanMessage = "Error: Something went wrong";
+
+		await appendToDebugLogFile("error", messageWithAnsi);
+
+		const logContent = getLogFileContent();
+		expect(logContent).toContain(expectedCleanMessage);
+		expect(logContent).not.toContain("\u001b[31m");
+		expect(logContent).not.toContain("\u001b[0m");
+	});
+
+	it("should strip complex ANSI escape sequences", async () => {
+		const messageWithComplexAnsi =
+			"\u001b[1;32mSuccess:\u001b[0m \u001b[33mWarning text\u001b[0m";
+		const expectedCleanMessage = "Success: Warning text";
+
+		await appendToDebugLogFile("log", messageWithComplexAnsi);
+
+		const logContent = getLogFileContent();
+		expect(logContent).toContain(expectedCleanMessage);
+		expect(logContent).not.toContain("\u001b[1;32m");
+		expect(logContent).not.toContain("\u001b[33m");
+	});
+
+	it("should preserve plain messages without ANSI codes", async () => {
+		const plainMessage = "This is a plain log message";
+
+		await appendToDebugLogFile("info", plainMessage);
+
+		const logContent = getLogFileContent();
+		expect(logContent).toContain(plainMessage);
+	});
+
+	it("should handle multiline messages with ANSI codes", async () => {
+		const multilineMessageWithAnsi =
+			"\u001b[31mLine 1 with color\u001b[0m\nLine 2 plain\n\u001b[32mLine 3 with different color\u001b[0m";
+		const expectedCleanMessage =
+			"Line 1 with color\nLine 2 plain\nLine 3 with different color";
+
+		await appendToDebugLogFile("warn", multilineMessageWithAnsi);
+
+		const logContent = getLogFileContent();
+		expect(logContent).toContain(expectedCleanMessage);
+		expect(logContent).not.toContain("\u001b[31m");
+		expect(logContent).not.toContain("\u001b[32m");
+	});
+
+	it("should maintain timestamp and log level formatting", async () => {
+		const message = "\u001b[31mTest message\u001b[0m";
+
+		await appendToDebugLogFile("error", message);
+
+		const logContent = getLogFileContent();
+		expect(logContent).toMatch(
+			/--- \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z error/
+		);
+		expect(logContent).toContain("Test message");
+		expect(logContent).toContain("---");
+	});
+
+	it("should handle empty messages", async () => {
+		await appendToDebugLogFile("debug", "");
+
+		const logContent = getLogFileContent();
+		expect(logContent).toMatch(
+			/--- \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z debug/
+		);
+	});
+
+	it("should handle messages with only ANSI codes", async () => {
+		const onlyAnsiMessage = "\u001b[31m\u001b[0m";
+
+		await appendToDebugLogFile("log", onlyAnsiMessage);
+
+		const logContent = getLogFileContent();
+		expect(logContent).not.toContain("\u001b[31m");
+		expect(logContent).not.toContain("\u001b[0m");
+		expect(logContent).toMatch(
+			/--- \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z log/
+		);
+	});
+});

packages/wrangler/src/utils/log-file.ts

@@ -2,6 +2,7 @@ import { appendFile } from "node:fs/promises";
 import path from "node:path";
 import { Mutex } from "miniflare";
 import onExit from "signal-exit";
+import stripAnsi from "strip-ansi";
 import { getEnvironmentVariableFactory } from "../environment-variables/factory";
 import { getGlobalWranglerConfigPath } from "../global-wrangler-config-path";
 import { logger } from "../logger";
@@ -51,7 +52,7 @@ export async function appendToDebugLogFile(
 ) {
 	const entry = `
 --- ${new Date().toISOString()} ${messageLevel}
-${message}
+${stripAnsi(message)}
 ---
 `;