--experimental-transform-types breaks &&= short circuiting

Version

24.4.0

Platform

Linux ssalb-xps 5.15.153.1-microsoft-standard-WSL2 #1 SMP Fri Mar 29 23:14:13 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

const ark = {}

ark.foo &&= `${ark.foo}1`

// ✅ without --experimental-transform-types: "undefined"
// ❌ with --experimental-transform-types: "undefinedundefined1"
console.log(ark.foo)

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

Should output undefined

What do you see instead?

"undefinedundefined1"

Additional information

No response

swc-project/swc#11037 – fixed upstream, but not yet released.

@ssalbdivad

Hey @ssalbdivad, thanks for opening this issue!
As far as I can tell, this bug has already been fixed in the latest version! 😁

We need to update amaro, the automatic update should run tonight

deps: update amaro to 1.1.4

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--experimental-transform-types breaks &&= short circuiting #59737

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What steps will reproduce the bug?

How often does it reproduce? Is there a required condition?

What is the expected behavior? Why is that the expected behavior?

What do you see instead?

Additional information

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--experimental-transform-types breaks &&= short circuiting #59737

Description

Version

Platform

Subsystem

What steps will reproduce the bug?

How often does it reproduce? Is there a required condition?

What is the expected behavior? Why is that the expected behavior?

What do you see instead?

Additional information

Activity

Renegade334 commented on Sep 2, 2025

pmarchini commented on Sep 27, 2025

marco-ippolito commented on Sep 27, 2025

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