noUselessEmptyExport
Diagnostic Category: lint/complexity/noUselessEmptyExport
Since: v1.0.0
Sources:
Disallow empty exports that don’t change anything in a module file.
An empty export {} is sometimes useful to turn a file that would otherwise be a script into a module.
Per the TypeScript Handbook Modules page:
In TypeScript, just as in ECMAScript 2015, any file containing a top-level import or export is considered a module. Conversely, a file without any top-level import or export declarations is treated as a script whose contents are available in the global scope.
However, an export {} statement does nothing if there are any other top-level import or export in the file.
Examples
Section titled ExamplesInvalid
Section titled Invalidimport { A } from "module";export {};code-block.js:2:1 lint/complexity/noUselessEmptyExport FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ This empty export is useless because there’s another export or import.
1 │ import { A } from “module”;
> 2 │ export {};
│ ^^^^^^^^^^
3 │
ℹ This import makes useless the empty export.
> 1 │ import { A } from “module”;
│ ^^^^^^
2 │ export {};
3 │
ℹ Safe fix: Remove this useless empty export.
1 1 │ import { A } from “module”;
2 │ - export·{};
3 2 │
export const A = 0;export {};code-block.js:2:1 lint/complexity/noUselessEmptyExport FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ This empty export is useless because there’s another export or import.
1 │ export const A = 0;
> 2 │ export {};
│ ^^^^^^^^^^
3 │
ℹ This export makes useless the empty export.
> 1 │ export const A = 0;
│ ^^^^^^
2 │ export {};
3 │
ℹ Safe fix: Remove this useless empty export.
1 1 │ export const A = 0;
2 │ - export·{};
3 2 │
Valid
Section titled Validexport {};