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

1 files changed, 35 insertions, 0 deletions

diff --git a/node_modules/postcss-merge-longhand/src/lib/canMerge.js b/node_modules/postcss-merge-longhand/src/lib/canMerge.js
new file mode 100644
index 00000000..d0f070db
--- /dev/null
+++ b/node_modules/postcss-merge-longhand/src/lib/canMerge.js
@@ -0,0 +1,35 @@
+'use strict';
+const isCustomProp = require('./isCustomProp');
+
+/** @type {(node: import('postcss').Declaration) => boolean} */
+const important = (node) => node.important;
+/** @type {(node: import('postcss').Declaration) => boolean} */
+const unimportant = (node) => !node.important;
+
+/* Cannot be combined with other values in shorthand 
+  https://www.w3.org/TR/css-cascade-5/#shorthand */
+const cssWideKeywords = ['inherit', 'initial', 'unset', 'revert'];
+/**
+ * @type {(props: import('postcss').Declaration[], includeCustomProps?: boolean) => boolean}
+ */
+module.exports = (props, includeCustomProps = true) => {
+  const uniqueProps = new Set(props.map((node) => node.value.toLowerCase()));
+
+  if (uniqueProps.size > 1) {
+    for (const unmergeable of cssWideKeywords) {
+      if (uniqueProps.has(unmergeable)) {
+        return false;
+      }
+    }
+  }
+
+  if (
+    includeCustomProps &&
+    props.some(isCustomProp) &&
+    !props.every(isCustomProp)
+  ) {
+    return false;
+  }
+
+  return props.every(unimportant) || props.every(important);
+};