canonical
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Canonical code style linter and formatter for JavaScript, SCSS and CSS.
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JavaScript
/**
* Require arrow functions to use a block statement (explicit return).
*
* Why enable this rule? Arrow functions' syntax can cause maintenance issues:
*
* - When you add additional lines to an arrow function's expression body, the
* function will now return `undefined`, unless you remember to add an
* explicit `return`.
* - The shorthand syntax is ambiguous in terms of returning objects.
* `(name) => {id: name}` is interpreted as a longhand arrow function with the
* label `id:`.
*
* Type: `Boolean`
*
* Value: `true`
*
* Version: `ES6`
*
* #### Example
*
* ```js
* "disallowShorthandArrowFunctions": true
* ```
*
* ##### Valid
*
* ```js
* // block statement
* evens.map(v => {
* return v + 1;
* });
* ```
*
* ##### Invalid
*
* ```js
* // single expression
* evens.map(v => v + 1);
* ```
*/
var assert = require('assert');
module.exports = function() {};
module.exports.prototype = {
configure: function(options) {
assert(
options === true,
this.getOptionName() + ' option requires a true value or should be removed'
);
},
getOptionName: function() {
return 'disallowShorthandArrowFunctions';
},
check: function(file, errors) {
file.iterateNodesByType('ArrowFunctionExpression', function(node) {
if (node.expression) {
errors.add(
'Use arrow function with explicit block and explicit return',
node.body.loc.start
);
}
});
}
};