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Enforce spacing around the * in yield* expressions (yield-star-spacing)

The --fix option on the command line can automatically fix some of the problems reported by this rule.

Rule Details

This rule enforces spacing around the * in yield* expressions.

To use this rule you either need to use the es6 environment or set ecmaVersion to 6 in parserOptions.

Options

The rule takes one option, an object, which has two keys before and after having boolean values true or false.

  • before enforces spacing between the yield and the *. If true, a space is required, otherwise spaces are disallowed.

  • after enforces spacing between the * and the argument. If it is true, a space is required, otherwise spaces are disallowed.

The default is {"before": false, "after": true}.

"yield-star-spacing": ["error", {"before": true, "after": false}]

The option also has a string shorthand:

  • {"before": false, "after": true}"after"
  • {"before": true, "after": false}"before"
  • {"before": true, "after": true}"both"
  • {"before": false, "after": false}"neither"
"yield-star-spacing": ["error", "after"]

Examples

after

Examples of correct code for this rule with the default "after" option:

/*eslint yield-star-spacing: ["error", "after"]*/
/*eslint-env es6*/

function* generator() {
  yield* other();
}

before

Examples of correct code for this rule with the "before" option:

/*eslint yield-star-spacing: ["error", "before"]*/
/*eslint-env es6*/

function *generator() {
  yield *other();
}

both

Examples of correct code for this rule with the "both" option:

/*eslint yield-star-spacing: ["error", "both"]*/
/*eslint-env es6*/

function * generator() {
  yield * other();
}

neither

Examples of correct code for this rule with the "neither" option:

/*eslint yield-star-spacing: ["error", "neither"]*/
/*eslint-env es6*/

function*generator() {
  yield*other();
}

When Not To Use It

If your project will not be using generators or you are not concerned with spacing consistency, you do not need this rule.

Further Reading

Version

This rule was introduced in ESLint 2.0.0-alpha-1.

Resources

© JS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/rules/yield-star-spacing