# no export from test file (no-export) Prevents exports from test files. If a file has at least 1 test in it, then this rule will prevent exports. ## Rule Details 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 seperate file when they need to be shared across tests. Examples of **incorrect** code for this rule: ```js export function myHelper() {} module.exports = function() {}; module.exports = { something: 'that should be moved to a non-test file', }; describe('a test', () => { expect(1).toBe(1); }); ``` Examples of **correct** code for this rule: ```js function myHelper() {} const myThing = { something: 'that can live here', }; describe('a test', () => { expect(1).toBe(1); }); ``` ## When Not To Use It Don't use this rule on non-jest test files.