From 22355f73f39f6186339b4e1c8f41f30862cdbd58 Mon Sep 17 00:00:00 2001
From: Boshen <1430279+Boshen@users.noreply.github.com>
Date: Wed, 23 Oct 2024 15:42:04 +0000
Subject: [PATCH] fix(minifier): do not remove `undefined` for destructuring
 patterns (#6828)

---
 .../peephole_substitute_alternate_syntax.rs        |  7 ++++++-
 tasks/coverage/snapshots/runtime.snap              | 14 +-------------
 2 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs b/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs
index f67905f03..5d78943b9 100644
--- a/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs
+++ b/crates/oxc_minifier/src/ast_passes/peephole_substitute_alternate_syntax.rs
@@ -298,7 +298,8 @@ impl<'a, 'b> PeepholeSubstituteAlternateSyntax {
         decl: &mut VariableDeclarator<'a>,
         ctx: Ctx<'a, 'b>,
     ) {
-        if decl.kind.is_const() {
+        // Destructuring Pattern has error throwing side effect.
+        if decl.kind.is_const() || decl.id.kind.is_destructuring_pattern() {
             return;
         }
         if decl.init.as_ref().is_some_and(|init| ctx.is_expression_undefined(init)) {
@@ -592,6 +593,10 @@ mod test {
 
         // shadowd
         test_same("(function(undefined) { let x = typeof undefined; })()");
+
+        // destructuring throw error side effect
+        test_same("var {} = void 0");
+        test_same("var [] = void 0");
     }
 
     #[test]
diff --git a/tasks/coverage/snapshots/runtime.snap b/tasks/coverage/snapshots/runtime.snap
index c42f65690..542927ad0 100644
--- a/tasks/coverage/snapshots/runtime.snap
+++ b/tasks/coverage/snapshots/runtime.snap
@@ -2,7 +2,7 @@ commit: 06454619
 
 runtime Summary:
 AST Parsed     : 18444/18444 (100.00%)
-Positive Passed: 18194/18444 (98.64%)
+Positive Passed: 18198/18444 (98.67%)
 tasks/coverage/test262/test/annexB/language/function-code/if-decl-else-decl-a-func-existing-block-fn-no-init.js
 minify error: Test262Error: Expected SameValue(«function f(){}», «undefined») to be true
 
@@ -735,21 +735,9 @@ codegen error: Test262Error: Expected SameValue(«"B"», «"A"») to be true
 tasks/coverage/test262/test/language/statements/async-generator/return-undefined-implicit-and-explicit.js
 minify error: Test262Error: Actual [tick 1, g1 ret, g2 ret, g3 ret, g4 ret, tick 2] and expected [tick 1, g1 ret, g2 ret, tick 2, g3 ret, g4 ret] should have the same contents. Ticks for implicit and explicit return undefined
 
-tasks/coverage/test262/test/language/statements/for/dstr/let-obj-init-undefined.js
-minify error: SyntaxError: Missing initializer in destructuring declaration
-
-tasks/coverage/test262/test/language/statements/for/dstr/var-obj-init-undefined.js
-minify error: SyntaxError: Missing initializer in destructuring declaration
-
 tasks/coverage/test262/test/language/statements/for-of/string-astral-truncated.js
 codegen error: Test262Error: Expected SameValue(«"\\"», «"\\ud801"») to be true
 
-tasks/coverage/test262/test/language/statements/let/dstr/obj-init-undefined.js
-minify error: SyntaxError: Missing initializer in destructuring declaration
-
-tasks/coverage/test262/test/language/statements/variable/dstr/obj-init-undefined.js
-minify error: SyntaxError: Missing initializer in destructuring declaration
-
 tasks/coverage/test262/test/language/statements/with/has-binding-call-with-proxy-env.js
 minify error: Test262Error: Actual [] and expected [has:Object] should have the same contents.