fix: replace fs.promises.mkdtemp with mkdir for Workers compatibility#160
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ebrainte wants to merge 1 commit intocloudflare:mainfrom
Open
fix: replace fs.promises.mkdtemp with mkdir for Workers compatibility#160ebrainte wants to merge 1 commit intocloudflare:mainfrom
ebrainte wants to merge 1 commit intocloudflare:mainfrom
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Cloudflare Workers' nodejs_compat (via unenv) does not implement
fs.mkdtemp or fs.promises.mkdtemp. This causes a runtime crash when
using @cloudflare/playwright in a Worker environment.
Replace mkdtemp(prefix) with mkdir(prefix + randomSuffix, { recursive: true })
in the three call sites within browserType.ts and chromium.ts. The random
suffix uses Math.random().toString(36).slice(2), providing sufficient
uniqueness for temporary directory names.
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Summary
fs.promises.mkdtempwithfs.promises.mkdir+ random suffix in 3 call sites@cloudflare/playwrightin a Cloudflare WorkerProblem
Cloudflare Workers'
nodejs_compat(via unenv) does not implementfs.mkdtemporfs.promises.mkdtemp. When deploying the Playwright MCP example (or any Worker using@cloudflare/playwright), the Worker crashes at runtime with an error like:This affects
@cloudflare/playwright@1.1.2(and likely earlier versions).Fix
Replace
mkdtemp(prefix)withmkdir(prefix + randomSuffix, { recursive: true })in:packages/playwright-core/src/server/browserType.tspackages/playwright-core/src/server/browserType.tspackages/playwright-core/src/server/chromium/chromium.tsThe random suffix uses
Math.random().toString(36).slice(2), providing sufficient uniqueness for temporary directory names while using onlyfs.promises.mkdirwhich IS available in Workers.Requires
compatibility_date >= 2025-09-23in the Worker'swrangler.tomlforfs.promises.mkdirto be available.Testing
Verified by deploying the
cloudflare/playwright-mcpexample Worker with these changes patched viapatch-package. The Worker successfully launches browsers, navigates pages, and takes screenshots without anymkdtemp-related errors.