chore(wallaby.js): prevent double imports

wallaby.js

@@ -3,6 +3,23 @@ const wallabyWebpack = require('wallaby-webpack'); // eslint-disable-line import
 // filter packages, e.g. 'core' / '{radio,radio-button}' / '{form,input*}'
 const packagePattern = '*';
 
+const replaceAll = (str, oldValue, newValue) => {
+  return str.split(oldValue).join(newValue);
+};
+
+const countOccurences = (str, subbstr) => {
+  return str.split(subbstr).length - 1;
+};
+
+const makeLionImportsRelative = file => {
+  // example:
+  // file.path: 'packages/package-name/src/my-element.js'
+  // old imports: '@lion/package-name'
+  // new imports: '../../package-name'
+  const nestLevel = countOccurences(file.path, '/') - 1; // 3 - 1 = 2
+  return replaceAll(file.content, '@lion/', '../'.repeat(nestLevel)); // '@lion/' => '../../'
+};
+
 module.exports = () => ({
   files: [
     { pattern: `packages/${packagePattern}/*.js`, load: false },
@@ -18,6 +35,9 @@ module.exports = () => ({
   env: {
     kind: 'chrome',
   },
+  preprocessors: {
+    '**/*.js': makeLionImportsRelative,
+  },
   postprocessor: wallabyWebpack(),
   setup: () => {
     // required to trigger test loading