feat: added i18n.translateError method

README.md

@@ -15,7 +15,8 @@
 * [Install](#install)
 * [Usage](#usage)
 * [API](#api)
-  * [i18n.translate(key, locale)](#i18ntranslatekey-locale)
+  * [i18n.translate(key, locale, ...args)](#i18ntranslatekey-locale-args)
+  * [i18n.translateError(key, locale, ...args)](#i18ntranslateerrorkey-locale-args)
   * [i18n.middleware(ctx, next)](#i18nmiddlewarectx-next)
   * [i18n.redirect(ctx, next)](#i18nredirectctx-next)
 * [Options](#options)
@@ -58,9 +59,15 @@ app.listen();
 
 ## API
 
-### i18n.translate(key, locale)
+### i18n.translate(key, locale, ...args)
 
-Returns translation for phrase `key` with the given `locale`.
+Returns translation for phrase `key` with the given `locale`.  Optionally pass additional arguments, e.g. format specifier replacements for use in the phrase.  For example if you have a phrase of "An error occurred %s" with a key of "ERROR_OCCURRED", and you use it as such `i18n.translate('ERROR_OCCURRED', 'en', 'some error message')` then it would return `'An error occurred some error message`.
+
+### i18n.translateError(key, locale, ...args)
+
+Returns the same string as `i18n.translate`, but wrapped with a new `Error` object with a property `no_translate` and a value set to `true`.
+
+This is an extremely useful method if you are using `koa-better-error-handler` package in the [Lad][] framework – as it will prevent a double translation from occurring.
 
 ### i18n.middleware(ctx, next)
 
@@ -189,3 +196,5 @@ For a list of all available locales see [i18n-locales][].
 [cabin]: https://cabinjs.com
 
 [multimatch]: https://github.com/sindresorhus/multimatch
+
+[lad]: https://github.com/ladjs/lad

package.json

@@ -20,41 +20,41 @@
     "Nick Baugh <niftylettuce@gmail.com> (http://niftylettuce.com/)"
   ],
   "dependencies": {
-    "@hapi/boom": "^9.0.0",
-    "boolean": "3.0.0",
+    "@hapi/boom": "^9.1.0",
+    "boolean": "3.0.1",
     "country-language": "^0.1.7",
     "debug": "^4.1.1",
     "i18n": "^0.9.1",
     "i18n-locales": "^0.0.4",
     "lodash": "^4.17.15",
-    "moment": "^2.24.0",
+    "moment": "^2.25.3",
     "multimatch": "^4.0.0",
-    "qs": "^6.9.1",
+    "qs": "^6.9.4",
     "titleize": "^2.1.0"
   },
   "devDependencies": {
-    "@babel/cli": "^7.8.3",
-    "@babel/core": "^7.8.3",
-    "@babel/preset-env": "^7.8.3",
+    "@babel/cli": "^7.8.4",
+    "@babel/core": "^7.9.6",
+    "@babel/preset-env": "^7.9.6",
     "@commitlint/cli": "^8.3.5",
     "@commitlint/config-conventional": "^8.3.4",
     "ava": "2.x",
-    "codecov": "^3.6.2",
+    "codecov": "^3.6.5",
     "cross-env": "6.x",
-    "eslint": "^6.8.0",
+    "eslint": "6.x",
     "eslint-config-xo-lass": "^1.0.3",
-    "eslint-plugin-node": "^11.0.0",
-    "fixpack": "^2.3.1",
+    "eslint-plugin-node": "^11.1.0",
+    "fixpack": "^3.0.6",
     "husky": "3.x",
     "koa": "^2.11.0",
     "koa-generic-session": "^2.0.4",
-    "lint-staged": "^10.0.3",
-    "nyc": "^15.0.0",
-    "remark-cli": "^7.0.1",
-    "remark-preset-github": "^0.0.16",
-    "sinon": "^8.1.1",
+    "lint-staged": "^10.2.2",
+    "nyc": "^15.0.1",
+    "remark-cli": "^8.0.0",
+    "remark-preset-github": "^1.0.0",
+    "sinon": "^9.0.2",
     "supertest": "^4.0.2",
-    "xo": "^0.25.3"
+    "xo": "0.25"
   },
   "engines": {
     "node": ">=6.4.0"

src/index.js

@@ -70,23 +70,25 @@ class I18N {
     this.configure(this.config);
 
     this.translate = this.translate.bind(this);
+    this.translateError = this.translateError.bind(this);
     this.middleware = this.middleware.bind(this);
     this.redirect = this.redirect.bind(this);
   }
 
-  translate(key, locale) {
+  translate(key, locale, ...args) {
+    locale = locale || this.config.defaultLocale;
     const { phrases } = this.config;
-    // eslint-disable-next-line prefer-rest-params
-    let args = Object.keys(arguments)
-      // eslint-disable-next-line prefer-rest-params
-      .map(key => arguments[key])
-      .slice(2);
-    if (typeof args === 'undefined') args = [];
     const phrase = phrases[key];
     if (typeof phrase !== 'string')
       throw new Error(`translation key missing: ${key}`);
-    args = [{ phrase, locale }, ...args];
-    return i18n.api.t(...args);
+    return i18n.api.t({ phrase, locale }, ...args);
+  }
+
+  translateError(key, locale, ...args) {
+    const str = this.translate(key, locale, ...args);
+    const err = new Error(str);
+    err.no_translate = true;
+    return err;
   }
 
   middleware(ctx, next) {

test/test.js

@@ -374,3 +374,11 @@ test(`logs error if saves fails for user ctx`, async t => {
   t.true(spy.calledOnce);
   t.true(spy.alwaysCalledWithExactly(saveError));
 });
+
+test('returns an error object with no_translate=true', t => {
+  const i18n = new I18N({ phrases, directory });
+  t.is(i18n.translate('hello', 'en'), 'hello');
+  const err = i18n.translateError('hello', 'es');
+  t.true(err.no_translate);
+  t.is(err.message, 'hola');
+});