prettier-solidity-config

Quickstart

/**
 * @file prettier.config.js
 * @version v1.0.7
 * @summary Prettier Configuration for Solidity
 */

'use strict';

const prettierConfig = require('prettier-config-solidity');
module.exports = prettierConfig;

Overview

Prettier configuration for Solidity

Install

Prettier

npm i -D prettier prettier-plugin-solidity --save-exact

with SolHint

npm install --save-dev solhint solhint-plugin-prettier prettier prettier-plugin-solidity --save-exact

{
  "plugins": ["prettier"],
  "rules": {
    "prettier/prettier": "error"
  }
}

Abstract

This configuration is optimized to reduce diff churn and improve AST results.

The following rules are employed, with specific reasonings to their choice (source: airbnb style guide):

whitespace

source@airbnb/javascript#whitespace--in-braces

• 19.12 Add spaces inside curly braces. eslint: object-curly-spacing

// bad
const foo = { clark: 'kent' };

// good
const foo = { clark: 'kent' };

arrow-parens

• 8.4 Always include parentheses around arguments for clarity and consistency. eslint: arrow-parens

source@airbnb/javascript#arrows--one-arg-parens

Why? Minimizes diff churn when adding or removing arguments.

// bad
[1, 2, 3].map((x) => x * x);

// good
[1, 2, 3].map((x) => x * x);

// bad
[1, 2, 3].map(
  (number) =>
    `A long string with the ${number}. It’s so long that we don’t want it to take up space on the .map line!`,
);

// good
[1, 2, 3].map(
  (number) =>
    `A long string with the ${number}. It’s so long that we don’t want it to take up space on the .map line!`,
);

// bad
[1, 2, 3].map((x) => {
  const y = x + 1;
  return x * y;
});

// good
[1, 2, 3].map((x) => {
  const y = x + 1;
  return x * y;
});

one var

• 13.2 Use one const or let declaration per variable or assignment. eslint: one-var

Why? It’s easier to add new variable declarations this way, and you never have to worry about swapping out a ; for a , or introducing punctuation-only diffs. You can also step through each declaration with the debugger, instead of jumping through all of them at once.

ref:eslint/rules/one-var

// bad
const items = getItems(),
  goSportsTeam = true,
  dragonball = 'z';

// bad
// (compare to above, and try to spot the mistake)
const items = getItems(),
  goSportsTeam = true;
dragonball = 'z';

// good
const items = getItems();
const goSportsTeam = true;
const dragonball = 'z';

20.2 Additional trailing comma: Yup. eslint: comma-dangle

Why? This leads to cleaner git diffs. Also, transpilers like Babel will remove the additional trailing comma in the transpiled code which means you don’t have to worry about the trailing comma problem in legacy browsers.

// bad - git diff without trailing comma
const hero = {
     firstName: 'Florence',
-    lastName: 'Nightingale'
+    lastName: 'Nightingale',
+    inventorOf: ['coxcomb chart', 'modern nursing']
};

// good - git diff with trailing comma
const hero = {
     firstName: 'Florence',
     lastName: 'Nightingale',
+    inventorOf: ['coxcomb chart', 'modern nursing'],
};

8.6 Enforce the location of arrow function bodies with implicit returns. eslint: implicit-arrow-linebreak

// bad
(foo) => bar;

(foo) => bar;

// good
(foo) => bar;
(foo) => bar;
(foo) => bar;

License

SPDX-License-Identifier: Apache-2.0