Simultaneous use of export equals and export default in a module

[tinganho]

I have some NPM modules written that uses the old default export syntax:

declare module 'my-module' {
    function test(): string;
    export = test;
}

To promote ES import syntax but still keep the old one, I wanted to add both the new and old default export syntax:

declare module 'my-module' {
    function test(): string;
    export default test;
    export = test; // An export assignment cannot be used in a module with other exported element
}

Though it complains that it cannot use an export assignment with other export statements.

I think it is reasonable to support both syntax simultaneously in a module. Because choosing between both syntax. I would choose export = before export default, simply because of no API breakage.

[kitsonk]

No it isn't really practical at all, because it isn't "magic" that produces the default export. It is added as a property on the export of the module. What is provided above is trying to export something as my-module.default and then overwriting it with a function named test and TypeScript is preventing you from describing something that contradicts itself.

I think what you might want to consider the solution to #5285 (--allowSyntheticDefaultImports), which allows you to import a module as if it were the shape you denoted.

[tinganho]

I think what you might want to consider the solution to #5285 (--allowSyntheticDefaultImports), which allows you to import a module as if it were the shape you denoted.

@kitsonk thanks that was what I wanted.

[tinganho]

There could be a problem. I'm currently doing the magic on the module itself and not relying on any module loader doing the magic for me. There could possibly be people that are not using --allowSyntheticDefaultImports so they cannot use one of my modules, unless they want to use the old import syntax. Telling all users that they need to add a flag just to use a module is little bit harsh also.

FYI. This is the magic I do:

declare var module: any;
module.exports = myModule;
module.exports.default = myModule;

[kitsonk]

declare module 'my-module' {
    const test: () => string & { default: () => string };
    export = test;
}

[tinganho]

Very neat trick!