chore: fix tests

Author: martinjagodic

packages/decap-cms-core/src/__tests__/backend.spec.js

@@ -460,7 +460,7 @@ describe('Backend', () => {
         partial: false,
         raw: '---\ntitle: "Hello World"\n---\n',
         data: { title: 'Hello World' },
-        meta: { path: 'src/posts/index.md' },
+        meta: { path: 'src/posts/index.md', path_type: 'slug' },
         i18n: {},
         label: null,
         isModification: true,

packages/decap-cms-core/src/lib/__tests__/i18n.spec.js

@@ -5,6 +5,8 @@ import * as i18n from '../i18n';
 jest.mock('../../reducers/collections', () => {
   return {
     selectEntrySlug: () => 'index',
+    // provide default implementation to avoid undefined in tests using i18n.getI18nDataFiles
+    isNestedSubfolders: () => false,
   };
 });
 

packages/decap-cms-core/src/lib/i18n.ts

@@ -379,7 +379,11 @@ export function getI18nDataFiles(
     return diffFiles;
   }
   const paths = getFilePaths(collection, extension, path, slug);
-  const subfolders = isNestedSubfolders(collection);
+  // When using i18n multiple folders, locale is encoded as a subfolder (e.g., `en/index.md`),
+  // so compare using the last two segments. Also respect nested subfolders collections.
+  const subfolders =
+    (getI18nInfo(collection) as I18nInfo).structure === I18N_STRUCTURE.MULTIPLE_FOLDERS ||
+    isNestedSubfolders(collection);
   const dataFiles = paths.reduce((acc, path) => {
     const dataFile = diffFiles.find(file => compareFilePathEndings(file.path, path, subfolders));
     if (dataFile) {