feat(unenv-preset): add native node:tty module support

[petebacondarwin]

Devin PR requested by @petebacondarwin

Adds support for the native node:tty module from workerd when the enable_nodejs_tty_module and experimental compatibility flags are enabled. This follows the same pattern as other experimental modules (inspector, sqlite, dgram, stream_wrap, repl).

The native code appears in workerd as of https://github.com/cloudflare/workerd/blob/main/src/node/tty.ts. It is currently experimental with no default enable date.

Implementation Comparison

Export	workerd	unenv	Breaking change?
isatty	returns false	returns false	No (same)
ReadStream	creates stub object	creates stub object	No (same)
WriteStream	creates stub object	creates stub object	No (same)

Implementation Notes

• The test validates throw behavior only when native module is enabled via compatibility flags

Human Review Checklist

• Verify the getTtyOverrides() function follows the same pattern as other experimental modules (requires experimental flag)
• Confirm the compatibility flag names match workerd's compatibility-date.capnp (enable_nodejs_tty_module / disable_nodejs_tty_module)
• Review the test coverage for both unenv stub and native workerd implementations

---

• 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):
  • Documentation not necessary because: internal experimental feature, follows existing patterns

---

[changeset-bot]

🦋 Changeset detected

Latest commit: 8929085

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

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR that start with 'DevinAI' or '@devin'.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[pkg-pr-new]

create-cloudflare

npm i https://pkg.pr.new/create-cloudflare@12023

@cloudflare/kv-asset-handler

npm i https://pkg.pr.new/@cloudflare/kv-asset-handler@12023

miniflare

npm i https://pkg.pr.new/miniflare@12023

@cloudflare/pages-shared

npm i https://pkg.pr.new/@cloudflare/pages-shared@12023

@cloudflare/unenv-preset

npm i https://pkg.pr.new/@cloudflare/unenv-preset@12023

@cloudflare/vite-plugin

npm i https://pkg.pr.new/@cloudflare/vite-plugin@12023

@cloudflare/vitest-pool-workers

npm i https://pkg.pr.new/@cloudflare/vitest-pool-workers@12023

@cloudflare/workers-editor-shared

npm i https://pkg.pr.new/@cloudflare/workers-editor-shared@12023

@cloudflare/workers-utils

npm i https://pkg.pr.new/@cloudflare/workers-utils@12023

wrangler

npm i https://pkg.pr.new/wrangler@12023

commit: 8929085

[claude]

Claude finished @petebacondarwin's task —— View job

---

Changeset Review

Reviewing changeset files for this PR...

Todo List:

• Read changeset guidelines
• Review .changeset/native-node-tty.md
• Check images for cute animals
• Validate changeset against criteria
• Post findings

---

✅ All changesets look good

The changeset .changeset/native-node-tty.md passes validation:

1. ✅ Version Type: Minor is appropriate for adding a new experimental feature
2. ✅ Changelog Quality: Clear description with explicit note about experimental nature and required flags
3. ✅ Markdown Headers: No h1/h2/h3 headers present
4. ✅ Analytics: Not applicable - no analytics changes
5. ✅ Experimental features: Properly notes this is experimental and lists the required compatibility flags (nodejs_compat, experimental, and enable_nodejs_tty_module)

The changeset correctly describes adding support for the native node:tty module and clearly explains the opt-in requirements for users.

---

[petebacondarwin]

Blocked on cloudflare/workerd#6064

[vicb]

Pete, could you please bump the workerd peer dependency on the preset to at least

I think you add another recent update to workerd needed for unenv, maybe this should also be done in another PR if not merged yet?

[petebacondarwin]

The workerd fix has landed cloudflare/workerd#6064 and this PR is now unblocked and the minimum peer dependency has been bumped. See v1.20260213.0
I think we may need to wait for the fix to get into production before actually merging this.

[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 4 additional findings.

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 4 additional findings in Devin Review.

[vicb]

LGTM, thanks Pete!