From cd55eeb77cc41f44cda2676c254dff3a6457ab02 Mon Sep 17 00:00:00 2001 From: "Alex Lam S.L" Date: Mon, 8 Jun 2020 06:42:09 +0100 Subject: [PATCH] fix corner case in `dead_code` (#3969) fixes #3967 --- lib/compress.js | 3 ++- test/compress/dead-code.js | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/lib/compress.js b/lib/compress.js index c8c08a0e..a56e9331 100644 --- a/lib/compress.js +++ b/lib/compress.js @@ -3938,7 +3938,8 @@ merge(Compressor.prototype, { }); def(AST_Binary, function(compressor) { return this.left.may_throw(compressor) - || this.right.may_throw(compressor); + || this.right.may_throw(compressor) + || this.operator == "in" && !is_object(this.right.tail_node()); }); def(AST_Block, function(compressor) { return any(this.body, compressor); diff --git a/test/compress/dead-code.js b/test/compress/dead-code.js index 22eb0d91..5506b95a 100644 --- a/test/compress/dead-code.js +++ b/test/compress/dead-code.js @@ -1193,3 +1193,24 @@ self_assignments: { } expect_stdout: "PASS 2 PASS PASS" } + +issue_3967: { + options = { + dead_code: true, + } + input: { + var a = "FAIL"; + try { + a = 0 in (a = "PASS"); + } catch (e) {} + console.log(a); + } + expect: { + var a = "FAIL"; + try { + a = 0 in (a = "PASS"); + } catch (e) {} + console.log(a); + } + expect_stdout: "PASS" +} -- 2.34.1