●Change8

Migrating to esbuild v0.27.7

Version v0.27.7 introduces 1 breaking change. This guide details how to update your code.

Released: 4/2/2026

1
Breaking Changes
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Migration Steps
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Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

TypeScript parameter properties lowering__publicField

Breaking Changes

●Issue #1

The lowering of TypeScript parameter properties has changed when targeting environments that do not support class fields (e.g., ES2021). Previously, class fields were incorrectly generated; now, they are correctly lowered using runtime helpers like `__publicField`.

Migration Steps

  1. 1
    Review generated output for TypeScript parameter properties if targeting older environments (pre-ES2022) to ensure compatibility with the new lowering strategy using runtime helpers.

Release Summary

This release fixes a bug where TypeScript parameter properties were incorrectly lowered as class fields when targeting older JavaScript environments. The lowering mechanism now correctly uses runtime helpers in these scenarios.

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View the full release notes and all changes for esbuild v0.27.7.

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