postcss,(plugins): nanocss, postcss-preset-env

1 files changed, 133 insertions, 0 deletions

diff --git a/node_modules/csso/cjs/restructure/prepare/specificity.cjs b/node_modules/csso/cjs/restructure/prepare/specificity.cjs
new file mode 100644
index 00000000..b62c3291
--- /dev/null
+++ b/node_modules/csso/cjs/restructure/prepare/specificity.cjs
@@ -0,0 +1,133 @@
+'use strict';
+
+const cssTree = require('css-tree');
+
+function ensureSelectorList(node) {
+    if (node.type === 'Raw') {
+        return cssTree.parse(node.value, { context: 'selectorList' });
+    }
+
+    return node;
+}
+
+function maxSpecificity(a, b) {
+    for (let i = 0; i < 3; i++) {
+        if (a[i] !== b[i]) {
+            return a[i] > b[i] ? a : b;
+        }
+    }
+
+    return a;
+}
+
+function maxSelectorListSpecificity(selectorList) {
+    return ensureSelectorList(selectorList).children.reduce(
+        (result, node) => maxSpecificity(specificity(node), result),
+        [0, 0, 0]
+    );
+}
+
+// §16. Calculating a selector’s specificity
+// https://www.w3.org/TR/selectors-4/#specificity-rules
+function specificity(simpleSelector) {
+    let A = 0;
+    let B = 0;
+    let C = 0;
+
+    // A selector’s specificity is calculated for a given element as follows:
+    simpleSelector.children.forEach((node) => {
+        switch (node.type) {
+            // count the number of ID selectors in the selector (= A)
+            case 'IdSelector':
+                A++;
+                break;
+
+            // count the number of class selectors, attributes selectors, ...
+            case 'ClassSelector':
+            case 'AttributeSelector':
+                B++;
+                break;
+
+            // ... and pseudo-classes in the selector (= B)
+            case 'PseudoClassSelector':
+                switch (node.name.toLowerCase()) {
+                    // The specificity of an :is(), :not(), or :has() pseudo-class is replaced
+                    // by the specificity of the most specific complex selector in its selector list argument.
+                    case 'not':
+                    case 'has':
+                    case 'is':
+                    // :matches() is used before it was renamed to :is()
+                    // https://github.com/w3c/csswg-drafts/issues/3258
+                    case 'matches':
+                    // Older browsers support :is() functionality as prefixed pseudo-class :any()
+                    // https://developer.mozilla.org/en-US/docs/Web/CSS/:is
+                    case '-webkit-any':
+                    case '-moz-any': {
+                        const [a, b, c] = maxSelectorListSpecificity(node.children.first);
+
+                        A += a;
+                        B += b;
+                        C += c;
+
+                        break;
+                    }
+
+                    // Analogously, the specificity of an :nth-child() or :nth-last-child() selector
+                    // is the specificity of the pseudo class itself (counting as one pseudo-class selector)
+                    // plus the specificity of the most specific complex selector in its selector list argument (if any).
+                    case 'nth-child':
+                    case 'nth-last-child': {
+                        const arg = node.children.first;
+
+                        if (arg.type === 'Nth' && arg.selector) {
+                            const [a, b, c] = maxSelectorListSpecificity(arg.selector);
+
+                            A += a;
+                            B += b + 1;
+                            C += c;
+                        } else {
+                            B++;
+                        }
+
+                        break;
+                    }
+
+                    // The specificity of a :where() pseudo-class is replaced by zero.
+                    case 'where':
+                        break;
+
+                    // The four Level 2 pseudo-elements (::before, ::after, ::first-line, and ::first-letter) may,
+                    // for legacy reasons, be represented using the <pseudo-class-selector> grammar,
+                    // with only a single ":" character at their start.
+                    // https://www.w3.org/TR/selectors-4/#single-colon-pseudos
+                    case 'before':
+                    case 'after':
+                    case 'first-line':
+                    case 'first-letter':
+                        C++;
+                        break;
+
+                    default:
+                        B++;
+                }
+                break;
+
+            // count the number of type selectors ...
+            case 'TypeSelector':
+                // ignore the universal selector
+                if (!node.name.endsWith('*')) {
+                    C++;
+                }
+                break;
+
+            // ... and pseudo-elements in the selector (= C)
+            case 'PseudoElementSelector':
+                C++;
+                break;
+        }
+    });
+
+    return [A, B, C];
+}
+
+module.exports = specificity;