Output is incorrect when there is an import declaration with an import clause that has one type only import specifier about esbuild

[hyrious]

Is it correct to have an import declaration with an empty import clause?

Yes. It is different between importing a module or not importing it at all. The former means to keep any side effects in the dependency.

For example, if ./foo.js has code:

// foo.js
console.log('side effect')

As a consequence the user ideally should see the log at runtime. That's why the import statement is kept.

[hyrious]

This is because you have set verbatimModuleSyntax: true. esbuild is generating the effectively same code as TypeScript compiler itself: TypeScript Playground

[jordimarimon]

I wasn't aware of the fact that the TypeScript compiler also behaves like this. Thanks for pointing it out!

Having said that, is it correct to have an import declaration with an empty import clause?

What side effects could cause if esbuild dropped entirely the import declaration if only types are being imported?

I can understand that esbuild may want to output similar code as the TypeScript compiler, but right now I don't see why it's important to keep the import declaration.

Feel free to close it if this is the expected behavior.

Thanks for the answer!