noExportsInTest

JavaScript (and super languages)

Summary

Rule available since: v1.6.0
Diagnostic Category: lint/suspicious/noExportsInTest
This rule doesn’t have a fix.
The default severity of this rule is error.
This rule belongs to the following domains:
- test
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

1
export function myHelper() {}
2
describe('a test', () => {
3
    expect(1).toBe(1);
4
});

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

1
function myHelper() {}
2
describe('a test', () => {
3
    expect(1).toBe(1);
4
});

How to configure

1
{
2
  "linter": {
3
    "rules": {
4
      "suspicious": {
5
        "noExportsInTest": "error"
6
      }
7
    }
8
  }
9
}