Maven minify plugin complains of semi colon

The error is

[ERROR] missing ; before statement at troveWebAnalytics.js line 7:17
            let gtmAgency;

The code is

return {
        registerPageView: function(tepid,domain,agency) {

            let gtmAgency;
            if (agency !== undefined) {
                gtmAgency = agency.alias;
            }

            let yearPublished;
            var pathArray = window.location.pathname.split("/");
            if (pathArray[1] == 'awa' && pathArray[2].length == 14) {
                    yearPublished = pathArray[2].slice(0,4);
            }
            ....
        }
    };

ChatGPT advised "The JavaScript snippet you provided doesn't seem to have any syntactical issues with the placement of semicolons that would cause the reported error. "

And I ended up fixing the issue by changing "let gtmAgency;" to "var gtmAgency;" and "let yearPublished;" to "var yearPublished;"

I am not happy about this fix. But I don't know what else I can try.

I understand your frustration about having to use var instead of let due to this issue. The problem you encountered indeed suggests there might be a compatibility issue with the minify Maven plugin you're using, particularly with its handling of ES6 syntax, which includes let and const.

Next Steps to Consider

Update the Minify Plugin: Check if there are any updates available for the minify Maven plugin that might include better support for modern JavaScript features. Sometimes, these tools lag behind in supporting the latest standards.

Configure the Plugin: Look into the configuration options for the minify plugin. There might be settings to enable or enhance support for ES6+ features.

Alternative Tools: Consider using a different minification tool that has robust ES6+ support. Popular tools like UglifyJS, Terser, or even Babel (with minification presets) are generally more up-to-date with JavaScript standards.

Babel as a Pre-step: Use Babel to transpile your code from ES6+ to ES5 before minification. This approach lets you write modern JavaScript while still ensuring compatibility with tools that only understand older standards. Here’s a basic setup: Install Babel: You can add Babel to your project using npm or yarn. Configure Babel: Set up a .babelrc configuration file to specify that you want to transpile ES6+ to ES5. Run Babel: Integrate this step into your build process before the minification step.

Report or Contribute: If you're sure this is a bug and if the project is open-source, consider reporting this issue to the plugin's maintainers. If you have the capability and time, you could also contribute a fix.

Local Testing: If changing the build tools is a significant change, you might want to set up a small test case locally. Write a simple JavaScript file using let and const, then run it through your current setup to see if the minification fails. This can confirm whether the issue is with the plugin's handling of ES6.

Example Babel Configuration

Here’s an example of a .babelrc file to transpile ES6 to ES5:

{
  "presets": [
    ["@babel/preset-env", {
      "targets": {
        "esmodules": false
      }
    }]
  ]
}

This setup ensures that your JavaScript is compatible with environments that only support ES5, which might help with your current toolchain issues.

Let me know if you need help setting up any of these solutions or if you have other questions about this issue!

sunmingtao / sample-code

Maven minify plugin complains of semi colon #350