ember/template-no-extra-mut-helper-argument

April 20, 2026 ยท View on GitHub

๐Ÿ’ผ This rule is enabled in the ๐Ÿ“‹ template-lint-migration config.

HBS Only: This rule applies to classic .hbs template files only (loose mode). It is not relevant for gjs/gts files (strict mode), where these patterns cannot occur.

Disallows passing more than one argument to the mut helper.

A common mistake when using the Ember handlebars template mut(attr) helper is to pass an extra value parameter to it when only attr should be passed. Instead, the value should be passed outside of mut.

Examples

This rule forbids the following:

{{my-component click=(action (mut isClicked true))}}

This rule allows the following:

{{my-component click=(action (mut isClicked) true)}}

References

  • See the documentation for the Ember handlebars template mut helper