chore: import upstream snapshot with attribution

packages/plugins/i18n-plugin/src/create-i18n-plugin.ts

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+ * SPDX-License-Identifier: MIT
+ */
+
+import { I18n, type I18nLanguage } from '@flowgram.ai/i18n';
+import { definePluginCreator } from '@flowgram.ai/core';
+
+export interface I18nPluginOptions {
+  locale?: string;
+  /**
+   * use `locale` instead
+   * @deprecated
+   */
+  localLanguage?: string;
+  /**
+   * if missingStrictMode is true
+   *  expect(I18n.t('Unknown')).toEqual('[missing "en-US.Unknown" translation]')
+   * else
+   *  expect(I18n.t('Unknown')).toEqual('Unknown')
+   */
+  missingStrictMode?: boolean;
+  languages?: I18nLanguage[] | Record<string, Record<string, any>>;
+  onLanguageChange?: (languageId: string) => void;
+}
+/**
+ * I18n Plugin
+ */
+export const createI18nPlugin = definePluginCreator<I18nPluginOptions>({
+  onInit: (ctx, _opts) => {
+    if (_opts.onLanguageChange) {
+      ctx.playground.toDispose.push(I18n.onLanguageChange(_opts.onLanguageChange));
+    }
+    if (_opts.languages) {
+      if (Array.isArray(_opts.languages)) {
+        I18n.addLanguages(_opts.languages);
+      } else {
+        I18n.addLanguages(
+          Object.keys(_opts.languages).map((key) => ({
+            languageId: key,
+            contents: (_opts.languages as any)![key],
+          }))
+        );
+      }
+    }
+    if (_opts.locale || _opts.localLanguage) {
+      I18n.locale = (_opts.locale || _opts.localLanguage)!;
+    }
+  },
+});

packages/plugins/i18n-plugin/src/index.ts

@@ -0,0 +1,7 @@
+/**
+ * Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+ * SPDX-License-Identifier: MIT
+ */
+
+export { I18n, type I18nLanguage } from '@flowgram.ai/i18n';
+export { createI18nPlugin, type I18nPluginOptions } from './create-i18n-plugin';