minimize and production setting for ~ of iteration code ReferenceError

[webpack-bot]

Bug report

What is the current behavior?
here is sample code.

function test() {
    try {
        const arr = [1];
        const arr2 = [1, 2];
        for (const x of arr) {
            console.log(x);
        }
        console.log(arr2);
        return true;
    } catch (err) {
        throw err;
    }
}

here is config

module.exports =
	{
		mode: 'production',
		optimization: {
			minimize: true
		},
		devtool: 'inline-source-map',
	};

ReferenceError: arr is not defined

seems like (try catch + for of) code is not working.

here is test repo
https://github.com/scarfunk/webpackbug-minimize

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?

Other relevant information:
webpack version: 4.39.3
Node.js version: 11.6.0 - ~/.nvm/versions/node/v11.6.0/bin/node
Operating System: macOS 10.14.4
Additional tools:

---

This issue was moved from webpack/webpack#9674 by @sokra. Original issue was by @scarfunk.

[sokra]

raw terser minimizes:

(function() {
    try {
        const arr = [1];
        for (const x of arr) {
        }
    } catch {
    }
})()

to

!function(){try{for(const c of arr);}catch{}}();

Using var arr instead of const arr works fine. Also moving the declaration out of the try block.

[scarfunk]

thanks for moving

[fabiosantoscode]

Silly bug :/ I was fixing the catch scope and broke for loops inside try blocks.

[fabiosantoscode]

Thank you for the report.