consistent-output.md

Enforce consistent use of output assertions in rule tests (consistent-output)

When writing tests for a fixable rule with RuleTester, you can assert the autofix output of your test cases. However, it can be easy to forget to assert the output of a particular test case.

Rule Details

This rule aims to ensure that if any invalid test cases have output assertions, then all test cases have output assertions.

Examples of incorrect code for this rule:

/* eslint eslint-plugin/consistent-output: error */

new RuleTester().run('example-rule', rule, {
  valid: [],
  invalid: [
    {
      code: 'foo',
      output: 'bar',
      errors: ['baz']
    },
    {
      code: 'bar',
      errors: ['baz']
    }
  ]
});

Examples of correct code for this rule:

/* eslint eslint-plugin/consistent-output: error */

new RuleTester().run('example-rule', rule, {
  valid: [],
  invalid: [
    {
      code: 'foo',
      output: 'bar',
      errors: ['baz']
    },
    {
      code: 'bar',
      output: 'qux',
      errors: ['baz']
    },
    {
      code: 'foo',
      output: null,
      errors: ['baz']
    }
  ]
});

Options

This rule takes an optional string enum option with one of the following values:

• "consistent" - (default) if any invalid test cases have output assertions, then all invalid test cases must have output assertions
• "always" - always require invalid test cases to have output assertions

When Not To Use It

If you're not writing fixable rules, or you want to write test cases without output assertions, do not enable this rule.

Further Reading

• RuleTester documentation