[wrangler] Smart cache directory detection for Yarn PnP compatibility by petebacondarwin · Pull Request #12466 · cloudflare/workers-sdk

petebacondarwin · 2026-02-07T14:27:26Z

This PR improves how Wrangler and Miniflare determine where to store cache files, making them compatible with Yarn PnP (Plug'n'Play) and other package managers that don't use traditional node_modules directories.

Wrangler Cache Directory Resolution

Wrangler now uses the following priority to determine the cache directory:

Environment variable override: WRANGLER_CACHE_DIR
Existing cache: Use existing node_modules/.cache/wrangler or .wrangler/cache if found
node_modules available: Create cache in node_modules/.cache/wrangler
Fallback: Use .wrangler/cache

Miniflare Cache Directory Resolution

Miniflare now uses the following priority to determine where to store its cf.json cache:

Environment variable override: MINIFLARE_CACHE_DIR
Existing cache: Use existing node_modules/.mf or .wrangler/cache if found
node_modules available: Create cache in node_modules/.mf
Fallback: Use .wrangler/cache

This approach:

Preserves backward compatibility for existing projects
Works automatically with Yarn PnP, pnpm, and other non-node_modules setups
Requires no configuration for most users

Environment Variables

WRANGLER_CACHE_DIR - Override wrangler's cache directory
MINIFLARE_CACHE_DIR - Override miniflare's cf.json cache directory

Implementation Notes

The cache folder path is computed fresh on each call (no in-memory caching). This design choice:

Ensures correct behavior when working directory changes (e.g., in tests)
Has negligible performance impact (~2-3 filesystem lookups per command)
Simplifies the code and improves test isolation

Tests
- Tests included/updated
- Automated tests not possible - manual testing has been completed as follows:
- Additional testing not necessary because:
Public documentation
- Cloudflare docs PR(s): Add WRANGLER_CACHE_DIR and MINIFLARE_CACHE_DIR environment variables cloudflare-docs#28364
- Documentation not necessary because:

A picture of a cute animal (not mandatory, but encouraged)

🦔

changeset-bot · 2026-02-07T14:27:34Z

🦋 Changeset detected

Latest commit: 189646a

The changes in this PR will be included in the next version bump.

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claude · 2026-02-07T14:27:48Z

Claude finished @petebacondarwin's task —— View job

Changeset Review Complete

Todo List:

Read changeset guidelines from .changeset/README.md
Review .changeset/configurable-temp-dir.md
Review .changeset/exclude-wrangler-from-pages-upload.md
Review .changeset/miniflare-cache-dir.md
Post review findings

✅ All changesets look good

All three changesets follow the guidelines:

Version types are appropriate (minor for new env vars/features, patch for bug fix and miniflare cache)
Descriptions are clear and meaningful
No problematic markdown headers
No analytics concerns

pkg-pr-new · 2026-02-07T14:32:07Z

create-cloudflare

npm i https://pkg.pr.new/create-cloudflare@12466

@cloudflare/kv-asset-handler

npm i https://pkg.pr.new/@cloudflare/kv-asset-handler@12466

miniflare

npm i https://pkg.pr.new/miniflare@12466

@cloudflare/pages-shared

npm i https://pkg.pr.new/@cloudflare/pages-shared@12466

@cloudflare/unenv-preset

npm i https://pkg.pr.new/@cloudflare/unenv-preset@12466

@cloudflare/vite-plugin

npm i https://pkg.pr.new/@cloudflare/vite-plugin@12466

@cloudflare/vitest-pool-workers

npm i https://pkg.pr.new/@cloudflare/vitest-pool-workers@12466

@cloudflare/workers-editor-shared

npm i https://pkg.pr.new/@cloudflare/workers-editor-shared@12466

@cloudflare/workers-utils

npm i https://pkg.pr.new/@cloudflare/workers-utils@12466

wrangler

npm i https://pkg.pr.new/wrangler@12466

commit: 189646a

devin-ai-integration

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 5 additional findings.

Add WRANGLER_HOME and WRANGLER_CACHE_DIR environment variables to allow users to configure where Wrangler stores temporary and cache files. This addresses compatibility issues with Yarn PnP projects that don't have node_modules directories. - Add WRANGLER_HOME env var to override .wrangler directory location - Add WRANGLER_CACHE_DIR env var to override cache directory location - Auto-detect Yarn PnP projects via .pnp.cjs/.pnp.js files - Update Miniflare to respect these env vars for cf.json cache - Add turbo.json passthrough for new environment variables Fixes #4299

Remove WRANGLER_HOME env var and simplify the implementation to only use: - WRANGLER_CACHE_DIR for wrangler's cache directory - MINIFLARE_CACHE_DIR for miniflare's cf.json cache - Automatic Yarn PnP detection (cached for performance) Both wrangler and miniflare now auto-detect Yarn PnP projects and use .wrangler/cache/ instead of node_modules/ directories.

Replace the Yarn PnP-specific detection with a more general approach: 1. Use WRANGLER_CACHE_DIR / MINIFLARE_CACHE_DIR env var if set 2. Use existing cache directory if found (node_modules/.cache/wrangler or .wrangler/cache) 3. Create cache in node_modules if it exists 4. Fall back to .wrangler/cache This approach is more robust and works with any package manager that doesn't use traditional node_modules directories.

Miniflare now only uses MINIFLARE_CACHE_DIR for env var override, keeping the two packages independent while still providing the same smart cache directory detection.

packages/miniflare/src/cf.ts

Remove module-level caching of cache folder paths in both Wrangler and Miniflare. The caching was causing test isolation issues where the cached path from one test would leak into subsequent tests running in different temp directories. The performance impact is negligible (2-3 extra filesystem lookups per command, ~10ms total) and removing the caching: - Fixes test isolation issues naturally - Simplifies the code - Removes the need for dynamic imports in tests Also renamed config-cache-without-cache-dir.test.ts to config-cache-wrangler-fallback.test.ts and updated tests to verify the new .wrangler/cache fallback behavior.

The .wrangler directory contains local cache and state files that should never be deployed. This aligns Pages upload behavior with Workers Assets, which already excludes .wrangler via .assetsignore.

ascorbic · 2026-02-16T17:29:52Z

packages/miniflare/src/cf.ts

+ * 5. .wrangler/cache as final fallback
+ */
+function getDefaultCfPath(): string {
+	// Priority 1: MINIFLARE_CACHE_DIR (miniflare-specific override)


Numbered comments are such an LLM tell 😀

petebacondarwin · 2026-02-16T17:39:26Z

Thanks @ascorbic

workers-devprod added this to workers-sdk Feb 7, 2026

github-project-automation bot moved this to Untriaged in workers-sdk Feb 7, 2026

petebacondarwin force-pushed the fix/4299-configurable-temp-dir branch 4 times, most recently from ef70325 to 64524ff Compare February 13, 2026 21:32

petebacondarwin force-pushed the fix/4299-configurable-temp-dir branch from 64524ff to e26e830 Compare February 16, 2026 09:37

petebacondarwin changed the title ~~[wrangler] Make temp file directory configurable for Yarn PnP compatibility~~ [wrangler] Smart cache directory detection for Yarn PnP compatibility Feb 16, 2026

petebacondarwin marked this pull request as ready for review February 16, 2026 14:04

petebacondarwin requested a review from a team as a code owner February 16, 2026 14:04

devin-ai-integration bot reviewed Feb 16, 2026

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petebacondarwin mentioned this pull request Feb 16, 2026

Add WRANGLER_CACHE_DIR and MINIFLARE_CACHE_DIR environment variables cloudflare/cloudflare-docs#28364

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petebacondarwin added 5 commits February 16, 2026 14:13

refactor: remove WRANGLER_CACHE_DIR fallback from miniflare

37cecfd

Miniflare now only uses MINIFLARE_CACHE_DIR for env var override, keeping the two packages independent while still providing the same smart cache directory detection.

chore: split changeset into separate wrangler and miniflare files

099396d

ascorbic reviewed Feb 16, 2026

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packages/miniflare/src/cf.ts Outdated Show resolved Hide resolved

packages/miniflare/src/cf.ts Outdated Show resolved Hide resolved

petebacondarwin force-pushed the fix/4299-configurable-temp-dir branch from c021c5a to 5920dc4 Compare February 16, 2026 14:46

petebacondarwin requested a review from ascorbic February 16, 2026 14:51

petebacondarwin added 2 commits February 16, 2026 14:55

remove unnecessary code, since the is now always a non-empty string

56bbe4e

fix: exclude .wrangler directory from Pages uploads

189646a

The .wrangler directory contains local cache and state files that should never be deployed. This aligns Pages upload behavior with Workers Assets, which already excludes .wrangler via .assetsignore.

petebacondarwin requested a review from a team as a code owner February 16, 2026 16:55

ascorbic reviewed Feb 16, 2026

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ascorbic approved these changes Feb 16, 2026

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github-project-automation bot moved this from Untriaged to Approved in workers-sdk Feb 16, 2026

petebacondarwin merged commit caf9b11 into main Feb 16, 2026
38 checks passed

petebacondarwin deleted the fix/4299-configurable-temp-dir branch February 16, 2026 17:39

github-project-automation bot moved this from Approved to Done in workers-sdk Feb 16, 2026

workers-devprod mentioned this pull request Feb 16, 2026

Version Packages #12547

Merged

dario-piotrowicz mentioned this pull request Feb 17, 2026

Wrangler: Fall back to global wrangler config directory for caching when no node_modules folder exists #12157

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[wrangler] Smart cache directory detection for Yarn PnP compatibility#12466

[wrangler] Smart cache directory detection for Yarn PnP compatibility#12466
petebacondarwin merged 8 commits intomainfrom
fix/4299-configurable-temp-dir

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Wrangler Cache Directory Resolution

Miniflare Cache Directory Resolution

Environment Variables

Implementation Notes

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