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noUselessEmptyExport (since v1.0.0)

Diagnostic Category: lint/complexity/noUselessEmptyExport

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 Examples

Invalid

Section titled Invalid
import { A } from "module";
export {};
complexity/noUselessEmptyExport.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 {};
complexity/noUselessEmptyExport.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 Valid
export {};
Section titled Related links