error in iOs 9 safari : `SyntaxError: Unexpected keyword 'const'. Const declarations are not supported in strict mode.`

• I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

repro:

• clone https://github.com/francoisromain/vuepress-ios9-bug
• install: npm i
• npm run dev
• open in a iOs 9 safari

What is expected?

The website should work in iOs 9 safari

What is actually happening?

blank page with an error: SyntaxError: Unexpected keyword 'const'. Const declarations are not supported in strict mode.

Other relevant information

This works well with vuepress 0.14.10, but not with 1.0.0-alpha.48

• My VuePress version is lower and euqal than 1.0.0-alpha.47:

  • VuePress version: 1.0.0-alpha.48
  • OS: macOs 10.13.6
  • Node.js version: 12.1.0
  • Browser version: safari iOs 9
  • Is this a global or local install? local
  • Which package manager did you use for the install? npm
  • Does this issue occur when all plugins are disabled?

• My VuePress version is higher than 1.0.0-alpha.47, the following is the output of npx vuepress info in my VuePress project:

Environment Info:

System: OS: macOS High Sierra 10.13.6 CPU: (8) x64 Intel® Core™ i7-2600 CPU @ 3.40GHz Binaries: Node: 12.1.0 - /usr/local/bin/node Yarn: Not Found npm: 6.9.0 - /usr/local/bin/npm Browsers: Chrome: Not Found Firefox: 66.0.5 Safari: 12.1.1 npmPackages: @vuepress/core: 1.0.0-alpha.48 @vuepress/theme-default: 1.0.0-alpha.48 vuepress: ^1.0.0-alpha.48 => 1.0.0-alpha.48 npmGlobalPackages: vuepress: Not Found

[francoisromain]

@ulivz I upgraded to the latest version and the problem is still here:

Environment Info:

  System:
    OS: macOS High Sierra 10.13.6
    CPU: (8) x64 Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
  Binaries:
    Node: 12.12.0 - /usr/local/bin/node
    Yarn: Not Found
    npm: 6.12.0 - /usr/local/bin/npm
  Browsers:
    Chrome: Not Found
    Firefox: 69.0.3
    Safari: 13.0.2
  npmPackages:
    @vuepress/core:  1.2.0 
    @vuepress/theme-default:  1.2.0 
    vuepress: ^1.2.0 => 1.2.0 
  npmGlobalPackages:
    vuepress: Not Found

[tretapey]

Hello, I haven’t tried this yet but I’m pretty sure that your browserslist is not including IOs 9, and there when it bundles is not supported.

Your actual browserslits configuration is: https://browserl.ist/?q=>1%25

I don’t think that giving support for IOs 9 is needed though.

Also see if you need to compile your node_modules folder as well, check this issue as reference https://github.com/babel/babel/issues/9712