noExportsInTest

Diagnostic Category: lint/suspicious/noExportsInTest

JavaScript (and super languages)

Since: v1.6.0

Sources:

Inspired from: jest/no-export

Description

Disallow using export or module.exports in files containing tests

This rule aims to eliminate duplicate runs of tests by exporting things from test files. If you import from a test file, then all the tests in that file will be run in each imported instance, so bottom line, don’t export from a test, but instead move helper functions into a separate file when they need to be shared across tests.

Examples

Invalid

export function myHelper() {}
describe('a test', () => {
    expect(1).toBe(1);
});

code-block.js:1:1 lint/suspicious/noExportsInTest ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not export from a test file.
  
  > 1 │ export function myHelper() {}
      │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ describe(‘a test’, () => {
    3 │     expect(1).toBe(1);

Valid

function myHelper() {}
describe('a test', () => {
    expect(1).toBe(1);
});

How to configure

{
  "linter": {
    "rules": {
      "suspicious": {
        "noExportsInTest": "error"
      }
    }
  }
}