Fix language files for Node+ESM

.config/babel/add-import-extension.js

@@ -0,0 +1,90 @@
+// Based on https://github.com/handsontable/handsontable/blob/bd7628544ff83d6e74a9cc949e2c3c38fef74d76/handsontable/.config/plugin/babel/add-import-extension.js
+
+const { existsSync, lstatSync } = require('fs');
+const { dirname, resolve } = require('path');
+const { types } = require('@babel/core');
+const { declare } = require('@babel/helper-plugin-utils');
+
+const VALID_EXTENSIONS = ['js', 'mjs'];
+
+const hasExtension = moduleName => VALID_EXTENSIONS.some(ext => moduleName.endsWith(`.${ext}`));
+const isCoreJSPolyfill = moduleName => moduleName.startsWith('core-js');
+const isLocalModule = moduleName => moduleName.startsWith('.');
+const isProcessableModule = (moduleName) => {
+    return !hasExtension(moduleName) && (isCoreJSPolyfill(moduleName) || isLocalModule(moduleName));
+};
+
+const createVisitor = ({ declaration, origArgs, extension = 'js' }) => {
+    return (path, { file }) => {
+        const { node: { source, exportKind, importKind } } = path;
+        const { opts: { filename } } = file;
+        const isTypeOnly = exportKind === 'type' || importKind === 'type';
+
+        if (!source || isTypeOnly || !isProcessableModule(source.value)) {
+            return;
+        }
+
+        const { value: moduleName } = source;
+        const absoluteFilePath = resolve(dirname(filename), moduleName);
+        const finalExtension = isCoreJSPolyfill(moduleName) ? 'js' : extension;
+
+        let newModulePath;
+
+        // Resolves a case where "import" points to a module name which exists as a file and
+        // as a directory. For example in this case:
+        // ```
+        // import { registerPlugin } from 'plugins';
+        // ```
+        // and with this directory structure:
+        //   |- editors
+        //   |- plugins
+        //     |- filters/
+        //     |- ...
+        //     +- index.js
+        //   |- plugins.js
+        //   |- ...
+        //   +- index.js
+        //
+        // the plugin will rename import declaration to point to the `plugins.js` file.
+        if (existsSync(`${absoluteFilePath}.js`)) {
+            newModulePath = `${moduleName}.${finalExtension}`;
+
+            // In a case when the file doesn't exist and the module is a directory it will
+            // rename to `plugins/index.js`.
+        } else if (existsSync(absoluteFilePath) && lstatSync(absoluteFilePath).isDirectory()) {
+            newModulePath = `${moduleName}/index.${finalExtension}`;
+
+            // And for other cases it simply put the extension on the end of the module path
+        } else {
+            newModulePath = `${moduleName}.${finalExtension}`;
+        }
+
+        path.replaceWith(declaration(...origArgs(path), types.stringLiteral(newModulePath)));
+    };
+};
+
+module.exports = declare((api, options) => {
+    api.assertVersion(7);
+
+    return {
+        name: 'add-import-extension',
+        visitor: {
+            // It covers default and named imports
+            ImportDeclaration: createVisitor({
+                extension: options.extension,
+                declaration: types.importDeclaration,
+                origArgs: ({ node: { specifiers } }) => [specifiers],
+            }),
+            ExportNamedDeclaration: createVisitor({
+                extension: options.extension,
+                declaration: types.exportNamedDeclaration,
+                origArgs: ({ node: { declaration, specifiers } }) => [declaration, specifiers],
+            }),
+            ExportAllDeclaration: createVisitor({
+                extension: options.extension,
+                declaration: types.exportAllDeclaration,
+                origArgs: () => [],
+            }),
+        }
+    };
+});

CHANGELOG.md

@@ -7,6 +7,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix ES module build to make importing language files possible in Node environment. [#1344](https://github.com/handsontable/hyperformula/issues/1344)
+
 ## [2.6.2] - 2024-02-15
 
 ### Changed

babel.config.js

@@ -31,7 +31,9 @@ module.exports = {
     },
     // Environment for transpiling files to be compatible with ES Modules.
     es: {
-      plugins: [],
+      plugins: [
+        ['./.config/babel/add-import-extension.js', { extension: 'mjs' }],
+      ],
     },
   },
 };

docs/guide/localizing-functions.md

@@ -9,16 +9,16 @@ register the language like so:
 
 ```javascript
 // import the French language pack
-import frFR from 'hyperformula/es/i18n/languages/frFR';
+import frFR from 'hyperformula/i18n/languages/frFR';
 
 // register the language
 HyperFormula.registerLanguage('frFR', frFR);
 ```
 
 ::: tip
 To import the language packs, use the module-system-specific dedicated bundles at:
-* **ES**: `hyperformula/es/i18n/languages/`
-* **CommonJS**: `hyperformula/commonjs/i18n/languages/`
+* **ES**: `hyperformula/i18n/languages/`
+* **CommonJS**: `hyperformula/i18n/languages/`
 * **UMD**: `hyperformula/dist/languages/`
 
 For the UMD build, the languages are accessible through `HyperFormula.languages`, e.g., `HyperFormula.languages.frFR`.