eslint-plugin-no-array-reduce

eslint-plugin-no-array-reduce

ESLint rule to disallow Array.reduce() method.

Method reduce() in most cases can be written as map(), filter() or one of the for() loops which benefits in code readability and makes it easier to maintain for future developers.

Subjectively there are cases where you still might want to use reduce() with eslint-disable.
There are many debates, discussions and other resources related to it:

• Jake Archibald
• Is reduce() bad
• Write more readable JavaScript

Install

npm install --save-dev eslint-plugin-no-array-reduce

Then extend eslint config:

{
  "extends": [
    // ...
    "plugin:no-array-reduce/recommended"
  ]
}

Fail

const products = [
  { name: 'milk', type: 'dairy' },
  { name: 'cheese', type: 'dairy' },
  { name: 'beef', type: 'meat' },
  { name: 'chicken', type: 'meat' },
];

// Add price to each product
const productsWithPrices = products.reduce((acc, product) => acc.concat({ ...product, price: 2.7 }), []);
// Filter dairy products
const dairies = products.reduce((acc, product) => (product.type === 'dairy' ? acc.concat(product) : acc), []);
// Group products by type
const productsByType = products.reduce(
  (acc, product) => ({
    ...acc,
    [product.type]: [...(acc[product.type] || []), product],
  }),
  [],
);

Pass

// Add price to each product
const productsWithPrices = products.map((product) => ({ ...product, price: 2.7 }));
// Filter dairy products
const dairies = products.filter((product) => product.type === 'dairy');
// Group products by type (ECMA stage 3 - https://github.com/tc39/proposal-array-grouping)
const productsByType = products.groupBy((product) => product.type);

_CodeSandbox

Contributing

All contributions are welcome!