dynamic imports: where the usage is in a separate statement from the import

[mrseanryan]

The current implementation of dynamic import handling, assumes that the import and the usage of the import are within the same statement.

This issue is about cases where the import is in a separate statement, from the usage.

Example:

usedExport is marked as unused.

const module = await import("./myModule");
const usedExport = module.usedExport;

Originally posted by @jp7837 in https://github.com/pzavolinsky/ts-unused-exports/pull/142#issuecomment-636184346

[mrseanryan]

Another example:

const module = import("./myModule");
module.then(({ usedExport }) => {
    console.log(usedExport); // Or whatever
});

[mrseanryan]

To support these cases, requires:

• detecting the assignment of the dynamic import, to an indentifier
• finding all usages of that identifier
• checking each usage, to see if what was imported, is actually used

simplification: We could assume that within a nested scope, an identifier is unique

[mrseanryan]

update: I'm not sure if we can ever support this 100% (at least, with the current architecture).

If a dynamic import can be assigned to a variable, then this means that the variable can be passed around into other functions, which could be in other modules (even dynamically imported modules!).

So the complexity is high.

If our architecture changed to have a fully compiled model to lean on, then this would be more practical to cover (possibly via ts-morph?).

[yujiaze]

any update about this?