Add unit tests for validateLanguageRequested

function

utils/validateLanguageRequested.test.js

@@ -0,0 +1,42 @@
+const supportedLanguages = require('../SUPPORTED-LANGUAGES.json');
+const { getSupportedLanguagesWithNames } = require("./formatSupportedLanguages");
+const {
+  validateLanguageRequested,
+} = require("./validateLanguageRequested");
+
+describe("validateLanguageRequested", () => {
+  it("should return true if the requested language is supported", () => {
+    const requestedLanguage = "en";
+
+    const result = validateLanguageRequested(requestedLanguage);
+
+    expect(result).toBe(true);    
+  });
+
+  it("should throw an error if no language is provided", () => {
+    const requestedLanguage = "";
+    const error = new Error("No language provided");
+
+    expect(() => {
+      validateLanguageRequested(requestedLanguage);
+    }).toThrowError(`${error.message}.\n\nPlease use one of these:\n\n${getSupportedLanguagesWithNames(supportedLanguages).join('\n')}`);
+  });
+
+  it("should throw an error if the requested language is not supported", () => {
+    const requestedLanguage = "invalid-language";
+    const error = new Error(`Language ${requestedLanguage} is not supported`);
+
+    expect(() => {
+      validateLanguageRequested(requestedLanguage);
+    }).toThrowError(`${error.message}.\n\nPlease use one of these:\n\n${getSupportedLanguagesWithNames(supportedLanguages).join('\n')}`);
+  });
+
+  it("should throw an error if the requested language is not supported by any engine", () => {
+    const requestedLanguage = "ab";
+    const error = new Error(`Language ${requestedLanguage} is not supported by any engine`);
+
+    expect(() => {
+      validateLanguageRequested(requestedLanguage);
+    }).toThrowError(`${error.message}.\n\nPlease use one of these:\n\n${getSupportedLanguagesWithNames(supportedLanguages).join('\n')}`);
+  });
+});