File size: 2,746 Bytes
a053984
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
import { generate } from 'css-tree';
import specificity from './specificity.js';

const nonFreezePseudoElements = new Set([
    'first-letter',
    'first-line',
    'after',
    'before'
]);
const nonFreezePseudoClasses = new Set([
    'link',
    'visited',
    'hover',
    'active',
    'first-letter',
    'first-line',
    'after',
    'before'
]);

export default function processSelector(node, usageData) {
    const pseudos = new Set();

    node.prelude.children.forEach(function(simpleSelector) {
        let tagName = '*';
        let scope = 0;

        simpleSelector.children.forEach(function(node) {
            switch (node.type) {
                case 'ClassSelector':
                    if (usageData && usageData.scopes) {
                        const classScope = usageData.scopes[node.name] || 0;

                        if (scope !== 0 && classScope !== scope) {
                            throw new Error('Selector can\'t has classes from different scopes: ' + generate(simpleSelector));
                        }

                        scope = classScope;
                    }

                    break;

                case 'PseudoClassSelector': {
                    const name = node.name.toLowerCase();

                    if (!nonFreezePseudoClasses.has(name)) {
                        pseudos.add(`:${name}`);
                    }

                    break;
                }

                case 'PseudoElementSelector': {
                    const name = node.name.toLowerCase();

                    if (!nonFreezePseudoElements.has(name)) {
                        pseudos.add(`::${name}`);
                    }

                    break;
                }

                case 'TypeSelector':
                    tagName = node.name.toLowerCase();
                    break;

                case 'AttributeSelector':
                    if (node.flags) {
                        pseudos.add(`[${node.flags.toLowerCase()}]`);
                    }

                    break;

                case 'Combinator':
                    tagName = '*';
                    break;
            }
        });

        simpleSelector.compareMarker = specificity(simpleSelector).toString();
        simpleSelector.id = null; // pre-init property to avoid multiple hidden class
        simpleSelector.id = generate(simpleSelector);

        if (scope) {
            simpleSelector.compareMarker += ':' + scope;
        }

        if (tagName !== '*') {
            simpleSelector.compareMarker += ',' + tagName;
        }
    });

    // add property to all rule nodes to avoid multiple hidden class
    node.pseudoSignature = pseudos.size > 0
        ? [...pseudos].sort().join(',')
        : false;
};