ember.js: Version 3.10.1 regression: use of const in strict mode, causing critical errors in e.g. Safari 9

In ember.min.js version 3.10.1 there are various usages of the const keyword in use strict mode:

@ember/-internals/glimmer, example: const e=L(["template-compiler:main"]
@ember/application/lib/application, example: const e=function(e,t){t...
@ember/engine/index, example: const e=v(["-bucket-cache:main"])
@ember/engine/instance, example: const e=u(["template-compiler:main"])

These cause syntax errors in Safari 9 (e.g. on iPhone 6S) and the Ember app fails to start. The error is:

SyntaxError: Use of const in strict mode

Ember 3.9.1 (the previous version) didn’t have this problem.

Repro:

npm install -g ember-cli@3.10.1 ember new test-app yarn install (edit config/targets.js to include Safari >= 9) ember build -prod (inspect dist/vendor.js and see the above-mentioned const occurrences)

Is this a bug, or am I missing something with respect to the build process?

About this issue

Original URL
State: closed
Created 5 years ago
Comments: 18 (10 by maintainers)

Most upvoted comments

I’m currently working on the fix for this. It is not easy, it means some pretty major changes to Ember’s build and testing setup, so that it dynamically compiles based on the consuming application’s Babel settings and targets.

pzuraq on Jul 16, 2019

@austinezell this is because we actually do not compile any of Ember’s code using your targets. At the moment Ember ships with two builds, the legacy build with everything transpiled, and the modern build targeted at the most recent browsers. We use feature detection based on your presets to pick which one to use, but this is the second time that something has broken because of it.

I think at this point we really need to work toward compiling Ember just-in-time using the host application’s build targets. It may end up being a bit of a hacky solution, but it’ll prevent these kinds of issues from cropping up.

pzuraq on Jun 25, 2019

Is there anything new about this problem?

BnitoBzh on Jul 3, 2019

One thing I have noticed in the build process is the message:

Browserslist: caniuse-lite is outdated. Please run next command yarn upgrade caniuse-lite browserslist

I’m guessing that this is a dependency of one of the ember-related packages and it’s something that we’re not responsible for updating ourselves. I wanted to mention it regardless though.

samcic on Jun 9, 2019

lifeart on Jul 10, 2019

I just tried to npm link this package and force my app to pull in the “legacy” version of ember. I ended up just verifying that my application is in fact already pulling in the legacy version.

The issue is that the legacy currently has 15 instances of const. Cloning this repo and running npm build then checking the dist/legacy/ folder verifies this. It does seem that @rwjblue’s assumption is correct and that this was caused by #17859 . Re-adding the line ['@babel/transform-template-literals', { loose: true }], into the to-es5.js module and re-running npm build successfully removed all instances of const from the legacy build.

austinezell on Jun 26, 2019