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Uglifier 3.1.0 produces "invalid assignment left-hand side"

See original GitHub issue

Good day. After updating to Uglifier 3.1.0 I am starting to get a JS error in production saying “invalid assignment left-hand side”. It happens on Heroku with Rails 5, Ruby 2.3. I am not really sure whether this should be reported here or at UglifyJS repo. After some inspection it appeared that the following line is problematic:

do 1 = 1, u /= 1,, e, u + a); while (1 = o() / s, !1)

This is a deobfuscated line of code that relates to jQuery 1 (it happens with jQuery 2 as well). Switching back to Uglifier 3.0.4 solves the problem. I can send minified and deobfuscated js files.

Issue Analytics

  • State:closed
  • Created 7 years ago
  • Reactions:4
  • Comments:14 (4 by maintainers)

github_iconTop GitHub Comments

ncuestacommented, Feb 27, 2017

@lautis Thanks for your dedication! This bug just hit us and you shipped the fix before we could even determine the root cause.

Just stopped by to say you’re awesome and, once again, thank you for your hard work.

lautiscommented, Feb 27, 2017

@bodrovis, in config/application.rb: config.assets.js_compressor = { reduce_vars: false, collapse_vars: false })

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