Question 1

How to use let-er with an existing build tool like Webpack?

Accepted Answer

let-er provides a CLI tool that can be run as a preprocessor in build scripts. You'll need to add it to your pipeline before other transpilers, but since it's niche, integration might require custom scripting as detailed documentation for common setups is limited.

Question 2

What's the performance impact of let-er's ES3 polyfill compared to native ES6?

Accepted Answer

The ES3 output uses a `try..catch` hack that the README notes is 10-20% slower than IIFEs, while ES6 output has zero performance difference since it relies on native `let`. For legacy browsers, this trade-off is necessary but can affect performance-sensitive applications.

Question 3

let-er vs Babel for block scoping?

Accepted Answer

Babel handles standard ES6 `let` and many other features, making it a comprehensive transpiler. let-er is specialized only for the rejected `let (..) {..}` syntax, so it's best used if you specifically want that explicit block syntax, not for general ES6 support.

Question 4

Can I use let-er with TypeScript?

Accepted Answer

TypeScript doesn't support this non-standard syntax natively. You'd need to transpile your code with let-er first and then process it with TypeScript, which complicates the workflow and isn't officially supported, potentially leading to integration issues.

Question 5

How to migrate existing var code to let-er syntax?

Accepted Answer

You must manually refactor `var` declarations to `let (..) {..}` blocks where appropriate, as let-er only transpiles its specific syntax and doesn't automate migration. This can be time-consuming and error-prone for large codebases.

Question 6

Is let-er still maintained since ES6 is now standard?

Accepted Answer

The project appears to be stable but niche, with last updates likely older. For most developers, standard ES6 `let` is sufficient, so let-er might not see active development, limiting its long-term viability in evolving ecosystems.

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