ember-unused-components

This addon searches for unused components in your Ember project. It has POD structure and whitelist support.

Installation

ember install ember-unused-components

Usage

Run in your app root directory:

ember unused:components

Expected output:

Searching for unused components:
 No. of components: 277
 No. of unused components: 2

 Unused components:
  - app/app-tab-panel
  - user/user-birthday

If you feel like there are too many components listed then check Configuration Section.

Advanced usage

Typically the addon should realize if you are using POD structure or not and find its way to components directory.

If you have problems with that, consider:

Forcing POD

To force using POD use --pods argument (alias: -p). Like this:

ember unused:components --pods

Addon will use default directory of POD components: app/modules/components

Forcing POD with the custom directory

Your app should be configured to have podModulePrefix property in config/environment.js if you are using POD but if it somehow doesn't work you can specify it through --pods-dir (alias: -pd). Like this:

ember unused:components --pods --pods-dir="modules/components-repository"

Configuration

In typical use cases, it should work out of the box and you don't have to configure anything but you can consider following options:

Whitelist

You can specify which components should not be treated as unused even if the addon couldn't find their usage occurrences. This happens when:

• you know that the component will be used in the future and you don't want to remove it and being reminded of that
• you use some kind of "dynamic name resolution" for your components

Add whitelist to your config/environment.js file:

ENV['ember-unused-components'] = {
  whitelist: [
    'app/app-tab-panel' // we will use it again soon
  ]
};

For the "dynamic name resolution" scenario consider following example. Typical dynamic component look like this:

Template

{{component name car=car}}

JavaScript

name: computed('car.type', function () {
  return `car-card-${this.get('car.type')}`;
});

Result

Which may result in having following components in use:

• car.type = 'suv' => {{car-card-suv car=car}}
• car.type = 'sport' => {{car-card-sport car=car}}
• car.type = 'sedan' => {{car-card-sedan car=car}}

Unfortunately, this static analysis tool doesn't understand it yet and doesn't know that your component car-card-suv has been used anywhere. You can whitelist these components from being marked as unused by referencing to them directly:

ENV['ember-unused-components'] = {
  whitelist: [
    'car-card-suv',
    'car-card-sport',
    'car-card-sedan'
  ]
};

or by using wildcard:

ENV['ember-unused-components'] = {
  whitelist: ['car-card-*']
};

Ignored files

A component might be used in some files like guidelines template (see ember-freestyle) that in fact does not indicate that it is in use. Best practice is to ignore that file:

ENV['ember-unused-components'] = {
  ignore: [
    'app/templates/freestyle.hbs' // this is our template with style guides
  ]
};

Removing components

Please raise an issue if you would like to see that functionality. It might be useful. But please consider that simple removal of:

• template.hbs
• component.js
• style.sass (if you use ember-component-css)

might not remove everything you would like. Examples:

• global CSS classes that are no longer used
• 3rd party JS libraries used only in that component
• translation keys that are no longer needed
• assets (images) that are no longer used
• local overwrites/adjustments for that component made by parent's CSS

So you'll still have some dead code because of unused components.

I encourage you to remove components from the list manually.

Best Practices

Once you delete unused components run the script once again :) You might find that now some other components are no longer used. This happens when the component is used in the unused component.

Example:

{{!-- users-list component --}}
{{#each users as |user|}}
  {{user-card user=user}}
{{/each}}

So user-card is being used but in unused component users-list. Once you will delete users-list component then user-card will not be longer used.

Roadmap

Future Plans and Ideas for the lib:

• address dependent "unused" component problem (check Best Practices)
• removal done by script
• removal of component with all its dependencies

If you feel like you need this functionality please raise an issue or event better Contribute!

Contributing

Installation

• git clone <repository-url>
• cd ember-unused-components
• npm install

Linting

• npm run lint:js
• npm run lint:js -- --fix

Running tests

• ember test – Runs the test suite on the current Ember version
• ember test --server – Runs the test suite in "watch mode"
• ember try:each – Runs the test suite against multiple Ember versions

Running the dummy application

• ember serve
• Visit the dummy application at http://localhost:4200.

For more information on using ember-cli, visit https://ember-cli.com/.

License

This project is licensed under the MIT License.