swc-project/swc · error

swcify

Error message

swcify: {:?}

What it means

A catch-all panic in the Statement-to-ModuleItem swcify conversion (swcify/stmt.rs:94). Each Babel Statement variant is mapped explicitly; the trailing arm fires when a Statement arrives whose variant has no explicit arm in this match — i.e. a statement kind the swcify layer has not implemented or does not expect. The debug-formatted statement ({:?}) names the exact unmapped variant, marking a conversion-completeness gap.

Solutions

1. Look at the {:?} output to identify the Statement variant, then add its swcify arm
2. Reject the Babel input earlier if that statement kind is unsupported in swc's AST
3. Update swc_estree_ast/swc_ecma_ast if the missing kind requires new node support

When it happens

Trigger: Thrown at crates/swc_estree_compat/src/swcify/stmt.rs:94 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/ff5ab42bb9d8d6bf. Report an issue: GitHub.

Appendix: source

Thrown at crates/swc_estree_compat/src/swcify/stmt.rs:94

            Statement::While(v) => v.swcify(ctx).into(),
            Statement::With(v) => v.swcify(ctx).into(),
            Statement::ClassDecl(v) => v.swcify(ctx).into(),
            Statement::ExportAllDecl(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            Statement::ExportDefaultDecl(v) => ModuleItem::ModuleDecl(v.swcify(ctx)),
            Statement::ExportNamedDecl(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            Statement::ForOf(v) => v.swcify(ctx).into(),
            Statement::ImportDecl(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            Statement::DeclClass(v) => v.swcify(ctx).into(),
            Statement::DeclFunc(v) => v.swcify(ctx).into(),
            Statement::DeclInterface(v) => v.swcify(ctx).into(),
            Statement::DeclModule(v) => v.swcify(ctx).into(),
            Statement::DeclareModuleExports(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            Statement::DeclTypeAlias(v) => v.swcify(ctx).into(),
            Statement::DeclVar(v) => v.swcify(ctx).into(),
            Statement::DeclExportDeclaration(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            Statement::DeclExportAllDeclaration(v) => ModuleItem::ModuleDecl(v.swcify(ctx).into()),
            _ => {
                todo!("swcify: {:?}", self)
            }
        }
    }
}

impl Swcify for BreakStatement {
    type Output = BreakStmt;

    fn swcify(self, ctx: &Context) -> Self::Output {
        BreakStmt {
            span: ctx.span(&self.base),
            label: self.label.swcify(ctx).map(|v| v.into()),
        }
    }
}

impl Swcify for ContinueStatement {
    type Output = ContinueStmt;

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