How to quickly configure ESLint for import sorting

I can get a bit obsessive with the way the code is formatted and styled not only in a team setting but in my own personal projects. Something that I took note of along the way is that I really liked by imports at the beginning of the file being ordered in a specific way:

1. Dependencies / Built-in modules (eg ‘react’, ‘react-router-dom’)
2. Internal routes of absolute folders (eg ‘components’, ‘assets’)
3. Relative routes (eg ./, ../)

And within those same subcategories, I also wanted it to be alphabetical.

ESLINT

With ESLint there are two options to flag errors or warnings when the imports are set in an incorrect order: sort-imports and with the help of a plugin eslint-plugin-import another rule with the name import/order.

sort-imports

sort-imports offers a way to alphabetically organize the imports using the declarations or the members of the declaration. For example:

Will become:

Great! We can also add a few options to ignore letter cases. In order to hook up this to ESLint we have to add a rule in the ESLint config file:

"rules": { 
    // ..other rules, 
    "sort-imports": 
    [
      "error", 
      { 
        "ignoreCase": true, 
        "ignoreDeclarationSort": true 
      }
    ], 
 }

You may have noticed I am ignored declaration sort here. This is intentional, we are going to have a more nuanced approach to sorting the declarations using eslint-plugin-import.

import/orders

For this to work the ESLint plugin must first be installed:

yarn add eslint-plugin-import --dev

Great! It offers a rule configuration to get very granular about how we want our imports to look. We can first differentiate the groups of our imports and split them up by groups:

"rules: { 
    // ..other rules, 
    "import/order": 
[
    1, 
    { "groups": 
        [
          "external", 
          "builtin", 
          "internal", 
          "sibling", 
          "parent", 
          "index"
        ], 
    } 
  ] 
  }

This will split the imports by the groups we specified at the beginning! Great! However, when using aliases with Typescript a few of our imports can be confused with dependencies. This particular rule can help us circumvent these particular edge cases by specifying something called pathGroups.

"groups": [
    "external", 
    "builtin", 
    "internal", 
    "sibling", 
    "parent", 
    "index"
 ], 
"pathGroups": [
    { 
      "pattern": "components", 
      "group": "internal" 
    }, 
    { 
      "pattern": "common", 
      "group": "internal" 
    }, 
    { 
      "pattern": "routes/ **", 
      "group": "internal" 
    }, 
    { 
      "pattern": "assets/**", 
      "group": "internal", 
      "position": "after" 
    }
 ], 
"pathGroupsExcludedImportTypes": 
   ["internal"], 
   "alphabetize": { 
      "order": "asc", 
      "caseInsensitive": true 
   }

Great now it will consider those aliased folders under the group internal!

As part of the linting process you could now run:

yarn lint --fix

And it’ll fix all import sorting warnings.

Share any configurations you use for sorting imports in the comments below!

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Originally published at https://relatablecode.com on October 10, 2021.