Issues

• Missing codesize reduction for reduce_vars with const/let declared inside nested block scopes

  terser/terser#1756 · Filter by author sbc100 opened on Oct 9, 2026

• Name cache renames an undeclared global in a module

  terser/terser#1753 · Filter by author thomasbachem opened on Oct 1, 2026

• Property mangling breaks option keys of DOM and Intl APIs (missing from domprops)

  terser/terser#1748 · Filter by author thomasbachem opened on Oct 1, 2026

• quote_keys quotes private class member names, producing invalid output

  terser/terser#1743 · Filter by author sstrand-hibox opened on Sep 23, 2026

• Inconsistent behavior when filtering out redundant inner-block variable assignment

  terser/terser#1739 · Filter by author Pecacheu opened on Sep 15, 2026
  1

• compress: unreachable switch case removal drops a CaseBlock function initializer

  terser/terser#1729 · Filter by author ko-success opened on Sep 1, 2026

• keep_fnames on both compress and mangle writes class initializer to an undeclared global (module mode)

  terser/terser#1727 · Filter by author Amixx opened on Aug 31, 2026

• Broken 5.51.0 and 5.51.1

  terser/terser#1725 · Filter by author fenn1ks opened on Aug 27, 2026
  1

• 5.51.0 regression: a called function is replaced with an empty arrow

  terser/terser#1724 · Filter by author bressler95tops opened on Aug 26, 2026
  2

• [BUG] Functions are inlined incorrectly if variable name matches a catch-block exception name

  terser/terser#1712 · Filter by author bayotop opened on Jul 23, 2026

• join_vars folds an assignment into an object literal with a computed accessor key, skipping the setter

  terser/terser#1709 · Filter by author sarathfrancis90 opened on Jul 18, 2026

• fix: _default_options never awaits async infer_options calls, always returns empty object

  terser/terser#1701 · Filter by author kumburovicbranko682-boop opened on Jun 27, 2026

• Mangle renames default parameter value to match destructured variable of same name, causing TDZ ReferenceError

  terser/terser#1698 · Filter by author ther12k opened on Jun 22, 2026

• Moving variable declaration to parameter list

  terser/terser#1696 · Filter by author GulgDev opened on Jun 20, 2026

• preserve_annotations preserves comments that merely mention an annotation token, not just real annotations

  terser/terser#1690 · Filter by author primarch42 opened on Jun 3, 2026

• fix: async infer_options called without await in _default_options

  terser/terser#1669 · Filter by author LucciHank opened on Apr 2, 2026

• fix: swallowed errors in infer_options hide real failures

  Breaking Change
  terser/terser#1667 · Filter by author LucciHank opened on Apr 2, 2026
  3

• Simplify simple arrow function

  terser/terser#1665 · Filter by author seannherdy opened on Mar 24, 2026
  2

• "-" character in name appears to break --source-map "content=" modifier CLI

  terser/terser#1664 · Filter by author Quafadas opened on Mar 16, 2026
  1

• How to make terser preserve \n when printing?

  terser/terser#1655 · Filter by author juj opened on Jan 15, 2026

• Property mangling can generate method names that collide with existing (including non-mangled) instance properties on the same prototype chain

  terser/terser#1653 · Filter by author liyan1044120608 opened on Dec 18, 2025

• [BUG] Bad output for Self-Defining Functions

  terser/terser#1649 · Filter by author DKingAlpha opened on Nov 28, 2025
  1

• Improve docs on MANGLE_PROP

  terser/terser#1645 · Filter by author fingerartur opened on Nov 10, 2025

• Mangle anything not reachable on public API surface

  terser/terser#1642 · Filter by author Danielku15 opened on Oct 13, 2025
  5

• Multi-line @license/copyright comments using single line comments not preserved, potential legal issues

  terser/terser#1641 · Filter by author kkmuffme opened on Oct 7, 2025