Specificity issue

[whatisaphone]

I found some behavior that I think is incorrect.

Example HTML:

<div class="a">
  <div class="b">hello</div>
</div>

Example input CSS:

.b { background: red }
.a .b { color: blue }

Example output CSS:

.b, .a .b { background: initial; color: initial }
.b { background: red }
.a .b { color: blue }

Before being run through postcss-autoreset, div.b is background: red. But afterwards, it becomes background: initial because the reset rule for .a .b has higher specificity. That smells like a bug to me.

I think this plugin should only reset selectors that have a single component. There's no reason to reset .b and then also reset .a .b – it's just a waste of bytes.

In the meantime, I was able to work around the issue with this config:

    require('postcss-autoreset')({
      rulesMatcher: (rule) => rule.selector.match(/^[.][\w-]+$/),
    }),

[maximkoretskiy]

Hi, and thank You for the suggestion.
As the main idea of this plugin is the isolation of all CSS rules, we could not change its default behavior to match Your concrete case. I mean, we could have an outer rule with the same selector (i.e. .a .b), and the most expectable for plugin behavior is to add all mentioned in project rules into reset until you decide to change this behavior.
rulesMatcher is aimed to solve this case and You used it properly.

[maximkoretskiy]

Mentioned your issue in README. Thank You.