Adding script to scrub locale files

For any keys in en/translation.yaml and missing in
<lang>/translation.yaml, this tool will add the key to
<lang>/missing.yaml. This is to facilitate translation of keys that have
been added to the app.

This also serves as a lint-like tool for translation files since they
will all be re-written when running.

package.json

@@ -20,6 +20,7 @@
     "test:unit": "jest",
     "test:lint": "eslint --ignore-path .gitignore .",
     "test:watch": "yarn test:unit --watch",
+    "i18n:scrub": "node ./script/i18n-scrub.js",
     "precommit": "run-s test:lint"
   },
   "browserslist": [
@@ -161,6 +162,7 @@
   "devDependencies": {
     "http-server": "^0.11.1",
     "husky": "^0.14.3",
+    "js-yaml": "^3.10.0",
     "webpack-dev-server": "^2.11.1"
   }
 }

script/i18n-scrub.js

@@ -0,0 +1,80 @@
+const util = require('util');
+const path = require('path');
+const fs = require('fs');
+const yaml = require('js-yaml');
+
+const readdir = util.promisify(fs.readdir);
+const readFile = util.promisify(fs.readFile);
+const writeFile = util.promisify(fs.writeFile);
+
+const localesDir = path.resolve(__dirname, '../src/locales');
+
+const loadLocales = async () => {
+  const languages = (await readdir(localesDir)).filter(name => name !== 'index.js');
+
+  let localeData = {};
+
+  await Promise.all(languages.map(async lang => {
+    const langDir = path.resolve(localesDir, lang);
+    const namespaces = (await readdir(langDir))
+      .filter(file => /\.yaml$/.test(file));
+
+    localeData[lang] = {};
+
+    await Promise.all(namespaces.map(async ns => {
+      const nsFile = path.resolve(langDir, ns);
+      localeData[lang][ns.replace('.yaml', '')] = yaml.safeLoad(await readFile(nsFile));
+    }));
+  }));
+
+  return localeData;
+};
+
+const saveLocales = async locales => {
+  await Promise.all(Object.keys(locales).map(async langName => {
+    const lang = locales[langName];
+
+    await Promise.all(Object.keys(lang).map(async nsName => {
+      const nsFile = path.resolve(localesDir, langName, `${ nsName }.yaml`);
+      const yamlDump = yaml.safeDump(lang[nsName], {
+        sortKeys: true
+      });
+      await writeFile(nsFile, yamlDump);
+    }));
+  }));
+};
+
+loadLocales()
+  .then(async locales => {
+    const requiredKeys = Object.keys(locales.en.translation);
+    const languages = Object.keys(locales).filter(lang => lang !== 'en');
+
+    languages.forEach(langName => {
+      const lang = locales[langName];
+      const presentKeys = Object.keys(lang.translation || {});
+
+      if (!lang.translation) {
+        lang.translation = {};
+      }
+
+      if (!lang.missing) {
+        lang.missing = {};
+      }
+
+      requiredKeys.forEach(key => {
+        if (!presentKeys.includes(key)) {
+          console.log(`es needs translation for "${ key }"`); // eslint-disable-line no-console
+          lang.missing[key] = locales.en.translation[key];
+        }
+      });
+    });
+
+    await saveLocales(locales);
+  })
+  .then(() => {
+    console.log('Done updating locales'); // eslint-disable-line no-console
+  })
+  .catch(e => {
+    console.log(e.toString()); // eslint-disable-line no-console
+    process.exit(1);
+  });