test(locale): add translations tests

Author: erezrokah

.eslintrc.json

@@ -4,7 +4,8 @@
   "env": {
     "browser": true,
     "node": true,
-    "es6": true
+    "es6": true,
+    "jest": true
   },
   "settings": {
     "react": {

package.json

@@ -9,7 +9,6 @@
   "dependencies": {},
   "devDependencies": {
     "@babel/cli": "^7.10.1",
-    "@babel/register": "^7.10.1",
     "@babel/core": "^7.10.2",
     "@babel/plugin-proposal-class-properties": "^7.10.1",
     "@babel/plugin-proposal-decorators": "^7.10.1",
@@ -18,6 +17,7 @@
     "@babel/plugin-transform-react-jsx": "^7.10.1",
     "@babel/polyfill": "^7.10.1",
     "@babel/preset-env": "^7.10.2",
+    "@babel/register": "^7.10.1",
     "auto-changelog": "^2.0.0",
     "babel-eslint": "^10.1.0",
     "babel-jest": "^26.0.1",
@@ -34,6 +34,7 @@
     "gh-release": "^3.4.0",
     "gotrue-js": "^0.9.21",
     "html-webpack-plugin": "^4.3.0",
+    "jest": "^26.0.1",
     "mkdirp": "^0.5.1",
     "mobx": "^3.2.2",
     "mobx-preact": "^1.1.0",
@@ -79,7 +80,9 @@
     "react-demo": "cd example && yarn && yarn start",
     "release": "node ./script/release.js",
     "lint": "eslint src",
-    "test": "run-s lint format-check",
+    "test": "run-s lint format-check test:unit",
+    "test:unit": "jest",
+    "test:unit:watch": "jest --watch",
     "version": "run-s release changelog"
   }
 }

src/translations/index.js

@@ -5,7 +5,6 @@ export const defaultLocale = "en";
 const translations = { en, fr };
 
 export const getTranslation = (key, locale = defaultLocale) => {
-  return translations[locale]
-    ? translations[locale][key] || key
-    : translations[defaultLocale][key] || key;
+  const translated = translations[locale] && translations[locale][key];
+  return translated || translations[defaultLocale][key] || key;
 };

src/translations/index.test.js

@@ -0,0 +1,34 @@
+describe("translations", () => {
+  beforeEach(() => {
+    jest.resetModules();
+  });
+
+  it("should return translation for default locale", () => {
+    const { getTranslation } = require("./");
+    expect(getTranslation("log_in")).toEqual("Log in");
+  });
+
+  it("should return translation for 'en' locale", () => {
+    const { getTranslation } = require("./");
+    expect(getTranslation("log_in", "en")).toEqual("Log in");
+  });
+
+  it("should return translation for 'fr' locale", () => {
+    const { getTranslation } = require("./");
+    expect(getTranslation("log_in", "fr")).toEqual("Connexion");
+  });
+
+  it("should return key for non existing translation", () => {
+    const { getTranslation } = require("./");
+    expect(getTranslation("unknown_key")).toEqual("unknown_key");
+  });
+
+  it("should default to 'en' on missing key", () => {
+    jest.mock("./en.json", () => ({ log_in: "Log in" }));
+    jest.mock("./fr.json", () => ({}));
+
+    const { getTranslation } = require("./");
+    expect(getTranslation("log_in")).toEqual("Log in");
+    expect(getTranslation("log_in", "fr")).toEqual("Log in");
+  });
+});