fix: treat :import and :export statements as pure

Author: fdintino

index.js

@@ -43,6 +43,8 @@ function normalizeNodeArray(nodes) {
 function localizeNode(rule, mode, localAliasMap) {
   const isScopePseudo = node =>
     node.value === ':local' || node.value === ':global';
+  const isImportExportPseudo = node =>
+    node.value === ':import' || node.value === ':export';
 
   const transform = (node, context) => {
     if (context.ignoreNextSpacing && !isSpacing(node)) {
@@ -115,9 +117,12 @@ function localizeNode(rule, mode, localAliasMap) {
         let childContext;
         const isNested = !!node.length;
         const isScoped = isScopePseudo(node);
+        const isImportExport = isImportExportPseudo(node);
 
+        if (isImportExport) {
+          context.hasLocals = true;
         // :local(.foo)
-        if (isNested) {
+        } else if (isNested) {
           if (isScoped) {
             if (node.nodes.length === 0) {
               throw new Error(`${node.value}() can't be empty`);

test.js

@@ -654,6 +654,18 @@ const tests = [
     error: /:global\(\) can't be empty/
   },
   */
+  {
+    should: 'consider :import statements pure',
+    input: ':import("~/lol.css") { foo: __foo; }',
+    options: { mode: 'pure' },
+    expected: ':import("~/lol.css") { foo: __foo; }',
+  },
+  {
+    should: 'consider :export statements pure',
+    input: ':export { foo: __foo; }',
+    options: { mode: 'pure' },
+    expected: ':export { foo: __foo; }',
+  },
 ];
 
 function process(css, options) {