chore: introduce i18next

.babelrc

@@ -13,10 +13,8 @@
   ],
   "plugins": [
     "@emotion",
-    "@babel/proposal-optional-chaining",
-    "@babel/proposal-nullish-coalescing-operator",
     "@babel/plugin-transform-typescript",
-    "react-intl-auto"
+    "react-intl-auto" // delete when migration to i18next is complete
   ],
   "env": {
     "test": {
@@ -32,4 +30,4 @@
       ]
     }
   }
-}
+}

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - uses: actions/setup-node@v2
         with:
-          node-version: '14.x'
+          node-version: "14.x"
       - name: Checkout
         uses: actions/checkout@v2
       - name: Get yarn cache directory path
@@ -33,6 +33,8 @@ jobs:
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./coverage/lcov.info
+      - name: Check translations
+        run: yarn run i18n --fail-on-update
   slack-notification:
     if: always()
     name: Slack Notification

.storybook/preview.tsx

@@ -7,7 +7,7 @@ import {
 } from "@apollo/client";
 import React, { ReactElement } from "react";
 
-import { Provider as IntlProvider } from "../src/locale";
+import { Provider as I18nProvider } from "../src/i18n";
 import { Provider as ThemeProvider } from "../src/theme";
 import { Provider as DndProvider } from "../src/util/use-dnd";
 
@@ -31,9 +31,9 @@ export const decorators = [
   (storyFn: () => ReactElement) => (
     <ApolloProvider client={mockClient}>
       <ThemeProvider>
-        <IntlProvider>
+        <I18nProvider>
           <DndProvider>{storyFn()}</DndProvider>
-        </IntlProvider>
+        </I18nProvider>
       </ThemeProvider>
     </ApolloProvider>
   ),

i18next-parser.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  locales: ["en", "ja"],
+  output: "src/i18n/translations/$LOCALE.yml",
+  input: ["src/**/*.{ts,tsx}"],
+  useKeysAsDefaultValue: true,
+};

package.json

@@ -24,9 +24,9 @@
         "storybook:screenshot": "storycap --serverCmd 'npx http-server ./storybook-static -p 6006' --serverTimeout 100000 http://localhost:6006 --max-old-space-size=2048",
         "cypress:open": "cypress open",
         "cypress:run": "cypress run",
-        "gen": "run-p gen:*",
-        "gen:gql": "graphql-codegen --config codegen.yml",
-        "gen:i18n": "extract-messages -d en -l=en,ja -o translations -f yaml 'src/**/*.ts*' --extractFromFormatMessageCall",
+        "gql": "graphql-codegen --config codegen.yml",
+        "i18n": "i18next",
+        "i18n:legacy": "extract-messages -d en -l=en,ja -o src/i18n/translations/legacy -f yaml 'src/**/*.ts*' --extractFromFormatMessageCall",
         "gen:doc:plugin": "ts-node -O '{\"module\":\"CommonJS\"}' ./bin/pluginDoc"
     },
     "engines": {
@@ -127,6 +127,7 @@
         "html-webpack-plugin": "^5.4.0",
         "html-webpack-tags-plugin": "^3.0.0",
         "husky": "^7.0.4",
+        "i18next-parser": "^6.3.0",
         "jest": "^27.5.0",
         "jest-transform-yaml": "^1.0.0",
         "json-loader": "^0.5.7",
@@ -177,6 +178,8 @@
         "github-markdown-css": "^5.1.0",
         "graphiql": "^1.8.7",
         "graphql": "^16.3.0",
+        "i18next": "^21.6.16",
+        "i18next-browser-languagedetector": "^6.1.4",
         "jotai": "^1.6.4",
         "js-file-download": "^0.4.12",
         "leaflet": "^1.7.1",
@@ -195,6 +198,7 @@
         "react-dom": "^17.0.2",
         "react-dropzone": "^12.0.5",
         "react-ga": "^3.3.0",
+        "react-i18next": "^11.16.7",
         "react-intl": "^5.24.6",
         "react-leaflet": "^3.2.5",
         "react-markdown": "^8.0.2",

src/app.tsx

@@ -16,7 +16,7 @@ import SettingsProjectList from "@reearth/components/pages/Settings/ProjectList"
 import WorkspaceSettings from "@reearth/components/pages/Settings/Workspace";
 import AssetSettings from "@reearth/components/pages/Settings/Workspace/Asset";
 import WorkspaceList from "@reearth/components/pages/Settings/WorkspaceList";
-import { Provider as IntlProvider } from "@reearth/locale";
+import { Provider as I18nProvider } from "@reearth/i18n";
 
 import { Provider as Auth0Provider } from "./auth";
 import RootPage from "./components/pages/Authentication/RootPage";
@@ -44,7 +44,7 @@ const App: React.FC = () => {
     <Auth0Provider>
       <GqlProvider>
         <ThemeProvider>
-          <IntlProvider>
+          <I18nProvider>
             <Suspense fallback={<Loading />}>
               <NotificationBanner />
               <StyledRouter>
@@ -70,7 +70,7 @@ const App: React.FC = () => {
                 <NotFound default />
               </StyledRouter>
             </Suspense>
-          </IntlProvider>
+          </I18nProvider>
         </ThemeProvider>
       </GqlProvider>
     </Auth0Provider>

src/components/atoms/ConfirmationModal/index.tsx

@@ -1,5 +1,6 @@
 import React from "react";
-import { useIntl } from "react-intl";
+
+import { useTranslation } from "@reearth/i18n";
 
 import Button from "../Button";
 import Modal from "../Modal";
@@ -23,7 +24,7 @@ const ConfirmationModal: React.FC<Props> = ({
   isOpen,
   onClose,
 }) => {
-  const intl = useIntl();
+  const { t } = useTranslation();
 
   const handleProceed = () => {
     onProceed();
@@ -37,19 +38,9 @@ const ConfirmationModal: React.FC<Props> = ({
       size="sm"
       onClose={onClose}
       button1={
-        <Button
-          text={buttonAction || intl.formatMessage({ defaultMessage: "Continue" })}
-          onClick={handleProceed}
-          buttonType="danger"
-        />
+        <Button text={buttonAction || t("Continue")} onClick={handleProceed} buttonType="danger" />
       }
-      button2={
-        <Button
-          text={intl.formatMessage({ defaultMessage: "Cancel" })}
-          onClick={onCancel ?? onClose}
-          buttonType="secondary"
-        />
-      }>
+      button2={<Button text={t("Cancel")} onClick={onCancel ?? onClose} buttonType="secondary" />}>
       {body}
     </Modal>
   );

src/components/molecules/Dashboard/Workspace.tsx

@@ -1,6 +1,5 @@
 import { Link } from "@reach/router";
 import React, { useMemo } from "react";
-import { useIntl } from "react-intl";
 import { useMedia } from "react-use";
 
 import Avatar from "@reearth/components/atoms/Avatar";
@@ -9,6 +8,7 @@ import Flex from "@reearth/components/atoms/Flex";
 import Icon from "@reearth/components/atoms/Icon";
 import Text from "@reearth/components/atoms/Text";
 import { Team as TeamType } from "@reearth/components/molecules/Dashboard/types";
+import { useTranslation } from "@reearth/i18n";
 import { styled, useTheme, metrics } from "@reearth/theme";
 import { metricsSizes } from "@reearth/theme/metrics";
 
@@ -20,7 +20,7 @@ export interface Props {
 }
 
 const Workspace: React.FC<Props> = ({ className, team }) => {
-  const intl = useIntl();
+  const { t } = useTranslation();
   const theme = useTheme();
   const isSmallWindow = useMedia("(max-width: 1024px)");
 
@@ -37,7 +37,7 @@ const Workspace: React.FC<Props> = ({ className, team }) => {
       <Content direction="column" justify="space-between">
         <Text size={isSmallWindow ? "m" : "l"} color={theme.main.text} weight="bold">
           {team?.name}
-          {intl.formatMessage({ defaultMessage: "'s workspace" })}
+          {t("'s workspace")}
         </Text>
         <Flex>
           <Flex flex={4}>

src/components/molecules/Settings/Account/AccountSection/index.tsx

@@ -8,7 +8,7 @@ import PasswordModal, {
 import Field from "@reearth/components/molecules/Settings/Field";
 import EditableItem from "@reearth/components/molecules/Settings/Project/EditableItem";
 import Section from "@reearth/components/molecules/Settings/Section";
-import { localesWithLabel } from "@reearth/locale";
+import { localesWithLabel } from "@reearth/i18n/legacy";
 import { styled } from "@reearth/theme";
 
 export type Theme = "dark" | "light" | "default";

src/components/pages/Authentication/hooks.ts

@@ -4,7 +4,7 @@ import { useCallback, useEffect } from "react";
 
 import { useAuth, useCleanUrl } from "@reearth/auth";
 import { useTeamsQuery } from "@reearth/gql";
-import { intl } from "@reearth/locale";
+import { intl } from "@reearth/i18n/legacy";
 import { useTeam, useNotification } from "@reearth/state";
 
 // TODO: move hooks to molecules (page components should be thin)

src/i18n/i18n.ts

@@ -0,0 +1,27 @@
+import i18n from "i18next";
+import LanguageDetector from "i18next-browser-languagedetector";
+import { initReactI18next } from "react-i18next";
+
+import en from "./translations/en.yml";
+import ja from "./translations/ja.yml";
+
+const resources = {
+  en: {
+    translation: en,
+  },
+  ja: {
+    translation: ja,
+  },
+};
+
+export const availableLanguages = Object.keys(resources);
+
+// eslint-disable-next-line import/no-named-as-default-member
+i18n.use(LanguageDetector).use(initReactI18next).init({
+  resources,
+  fallbackLng: "en",
+  keySeparator: false,
+  returnEmptyString: false,
+});
+
+export default i18n;

src/i18n/index.tsx

@@ -0,0 +1,3 @@
+export { useTranslation } from "react-i18next";
+export { default as Provider } from "./provider";
+export { default as PublishedProvider } from "./publishedProvider";

src/locale/locale.ts → src/i18n/legacy/locale.ts

@@ -1,7 +1,7 @@
 import { createIntl, createIntlCache } from "react-intl";
 
-import en from "../../translations/en.yml";
-import ja from "../../translations/ja.yml";
+import en from "../translations/legacy/en.yml";
+import ja from "../translations/legacy/ja.yml";
 
 export const locales = ["en", "ja"] as const;
 

src/locale/provider.tsx → src/i18n/legacy/provider.tsx

@@ -1,12 +1,12 @@
-import React, { PropsWithChildren } from "react";
+import React, { ReactNode } from "react";
 import { IntlProvider } from "react-intl";
 
 import { useAuth } from "@reearth/auth";
 import { useLanguageQuery } from "@reearth/gql";
 
 import { Locale, defaultLocale, locales, messages } from "./locale";
 
-export default function Provider({ children }: PropsWithChildren<{}>) {
+export default function Provider({ children }: { children?: ReactNode }) {
   const { isAuthenticated } = useAuth();
   const { data } = useLanguageQuery({ skip: !isAuthenticated });
   const locale =

src/locale/publishedProvider.tsx → src/i18n/legacy/publishedProvider.tsx

@@ -1,11 +1,11 @@
-import React, { PropsWithChildren } from "react";
+import React, { ReactNode } from "react";
 import { IntlProvider } from "react-intl";
 
 import { defaultLocale, messages } from "./locale";
 
 const locale = navigator.language.split("_")[0];
 
-export default function PublishedProvider({ children }: PropsWithChildren<{}>) {
+export default function PublishedProvider({ children }: { children?: ReactNode }) {
   return (
     <IntlProvider locale={locale} defaultLocale={defaultLocale} messages={messages[locale]}>
       {children}

src/i18n/provider.tsx

@@ -0,0 +1,24 @@
+import React, { ReactNode, useEffect } from "react";
+import { I18nextProvider } from "react-i18next";
+
+import { useAuth } from "@reearth/auth";
+import { useLanguageQuery } from "@reearth/gql";
+
+import i18n from "./i18n";
+import { Provider as LegacyProvider } from "./legacy";
+
+export default function Provider({ children }: { children?: ReactNode }) {
+  const { isAuthenticated } = useAuth();
+  const { data } = useLanguageQuery({ skip: !isAuthenticated });
+  const locale = data?.me?.lang;
+
+  useEffect(() => {
+    i18n.changeLanguage(locale === "und" ? undefined : locale);
+  }, [locale]);
+
+  return (
+    <I18nextProvider i18n={i18n}>
+      <LegacyProvider>{children}</LegacyProvider>
+    </I18nextProvider>
+  );
+}

src/i18n/publishedProvider.tsx

@@ -0,0 +1,13 @@
+import React, { ReactNode } from "react";
+import { I18nextProvider } from "react-i18next";
+
+import i18n from "./i18n";
+import { PublishedProvider as LegacyProvider } from "./legacy";
+
+export default function PublishedProvider({ children }: { children?: ReactNode }) {
+  return (
+    <I18nextProvider i18n={i18n}>
+      <LegacyProvider>{children}</LegacyProvider>
+    </I18nextProvider>
+  );
+}

src/i18n/translations/en.yml

@@ -0,0 +1,3 @@
+Continue: Continue
+Cancel: Cancel
+'''s workspace': '''s workspace'

src/i18n/translations/ja.yml

@@ -0,0 +1,3 @@
+Continue: キャンセル
+Cancel: 続ける
+'''s workspace': ' のワークスペース'

src/publishedapp.tsx

@@ -2,17 +2,17 @@ import React from "react";
 
 import PublishedPage from "@reearth/components/pages/Published";
 
-import { PublishedProvider as IntlProvider } from "./locale";
+import { Provider as I18nProvider } from "./i18n";
 import { PublishedAppProvider as ThemeProvider } from "./theme";
 import { Provider as DndProvider } from "./util/use-dnd";
 
 export default function App() {
   return (
     <ThemeProvider>
       <DndProvider>
-        <IntlProvider>
+        <I18nProvider>
           <PublishedPage />
-        </IntlProvider>
+        </I18nProvider>
       </DndProvider>
     </ThemeProvider>
   );

src/test/utils.tsx

@@ -2,7 +2,7 @@ import { MockedProvider as MockedGqlProvider, MockedResponse } from "@apollo/cli
 import { render as rtlRender } from "@testing-library/react";
 import React from "react";
 
-import { Provider as IntlProvider } from "../locale";
+import { Provider as I18nProvider } from "../i18n";
 import { Provider as ThemeProvider } from "../theme";
 
 const render = (
@@ -14,7 +14,7 @@ const render = (
     return (
       <MockedGqlProvider mocks={queryMocks} addTypename={false}>
         <ThemeProvider>
-          <IntlProvider>{children}</IntlProvider>
+          <I18nProvider>{children}</I18nProvider>
         </ThemeProvider>
       </MockedGqlProvider>
     );

webpack.config.js

@@ -102,6 +102,7 @@ module.exports = (env, args = {}) => {
         },
         {
           test: /\.ya?ml$/,
+          // Delete yaml-flat-loader and use a regular yaml loader when migration to i18next is complete
           use: [{ loader: "json-loader" }, { loader: "yaml-flat-loader" }],
         },
         {