swc-project/swc · error

swc currently does not support importing typescript module f

Error message

swc currently does not support importing typescript module from babel

What it means

A todo!() stub in `Swcify for TSType` (swcify/typescript.rs:100). Converting Babel's TS types back into swc TypeScript nodes is not implemented in this path — the whole impl is a placeholder that unconditionally panics when any TSType node is swcified. It fires whenever the Babel input contains TypeScript type annotations whose types must be converted back to swc AST, marking a known unimplemented conversion area rather than a bad input.

Source

Thrown at crates/swc_estree_compat/src/swcify/typescript.rs:100

    }
}

impl Swcify for TSTypeAnnotation {
    type Output = TsTypeAnn;

    fn swcify(self, ctx: &Context) -> Self::Output {
        TsTypeAnn {
            span: ctx.span(&self.base),
            type_ann: self.type_annotation.swcify(ctx),
        }
    }
}

impl Swcify for TSType {
    type Output = Box<TsType>;

    fn swcify(self, _: &Context) -> Self::Output {
        todo!("swc currently does not support importing typescript module from babel")
    }
}

impl Swcify for SuperTypeParams {
    type Output = TsTypeParamInstantiation;

    fn swcify(self, ctx: &Context) -> Self::Output {
        match self {
            SuperTypeParams::Flow(_) => unimplemented!("flow type"),
            SuperTypeParams::TS(v) => v.swcify(ctx),
        }
    }
}

impl Swcify for Access {
    type Output = Accessibility;

    fn swcify(self, _: &Context) -> Self::Output {

View on GitHub (pinned to 5176682b65)

Solutions

1. Avoid the swcify path for TypeScript-heavy Babel ASTs until TSType conversion is implemented
2. Contribute the TSType-to-TsType mapping arms to swc_estree_compat
3. Strip type annotations before conversion if downstream only needs the JS skeleton

When it happens

Trigger: Thrown at crates/swc_estree_compat/src/swcify/typescript.rs:100 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/b28008de635e85ed. Report an issue: GitHub.