Ignore @import statements which are not followed by url(..)

packages/concat-style-loader/concat.js

@@ -51,6 +51,11 @@ function getImportStatements(content, ignoreComments = true) {
   const matches = [];
   let match;
   while ((match = regex.exec(content))) {
+    // If import statement is not followed by a `url(...)`
+    if (typeof match[1] === 'undefined') {
+      continue;
+    }
+
     match.endIndex = match.index + match[1].length;
 
     if (matchIsInComment(content, match) && ignoreComments) {

packages/concat-style-loader/test/concat.test.js

@@ -36,13 +36,24 @@ describe('getImportStatements()', () => {
     const {getImportStatements} = require('../concat');
     const contents = `
       @import url('./other.css.liquid');
-      /* @import url('./another.css.liquid'); */
+      /* @import url('./anotherOne.css.liquid'); */
+      // @import url('./something.css.liquid');
       @import url('./another.css.liquid');`;
     const imports = getImportStatements(contents);
 
     expect(imports.length).toBe(2);
   });
 
+  test('ignores @import statements which are not followed by a url(...) statement', () => {
+    const {getImportStatements} = require('../concat');
+    const contents = `
+      @import './something.css.liquid';
+      @import url('./another.css.liquid');`;
+    const imports = getImportStatements(contents);
+
+    expect(imports.length).toBe(1);
+  });
+
   test('can include @import statements inside comments', () => {
     const {getImportStatements} = require('../concat');
     const contents = `