added new validations to the code

cli.js

@@ -2,7 +2,6 @@
 
 const { Command, Argument } = require('commander');
 const program = new Command();
-const supportedLanguages = require('./SUPPORTED-LANGUAGE.json');
 const { configPath } = require('./utils/getConfigPath');
 const { translateController } = require('./controllers/translateController');
 
@@ -14,7 +13,7 @@ program
 program.command('translate')
   .description('Translate a text and put the result on the files in the output directory')
   .argument('<text>', 'Text to translate')
-  .addArgument(new Argument('<source-language>', 'Source language of the string').choices(supportedLanguages))
+  .argument('<source-language>', 'Source language of the string')
   .argument('<name-of-translation>', 'Name of your translation')
   .option('-e, --engine <string>', "Engine to use for the translation. In case you don't define it will be use by default all the translation engines that are free and doesn't requires API Key.")
   .option('-s, --settings-file <string>', 'Path to the settings file', configPath)

controllers/translateController.js

@@ -4,17 +4,17 @@ const { validateSettingsFile } = require('../utils/validateSettingsFile');
 const { dset: setDeepValue } = require('dset');
 const { validateAndPromptUserJSONFiles } = require('../utils/validateAndPromptUserJSONFiles');
 const { setTranslateWithFallbackEngines, isEngineValid } = require('../services/translateService');
+const { validateLanguageRequested } = require('../utils/validateLanguageRequested');
 
 const translateController = async (text, sourceLanguage, nameOfTranslation, options) => {
   const settingsFilePath = parsePath(options.settingsFile);
-  const isValidSettingsFile = validateSettingsFile(settingsFilePath);
-
-  if (!isValidSettingsFile) throw new Error('Invalid settings file');
+  validateSettingsFile(settingsFilePath);
+  validateLanguageRequested(sourceLanguage, options.engine);
+
   if (!text) throw new Error('No text to translate provided');
-  if (!sourceLanguage) throw new Error('No source language provided');
   if (!nameOfTranslation) throw new Error('No name of translation provided');
 
-  const { languages, basePath, translationEngines: settingsTranslationEngines } = require(settingsFilePath); 
+  const { languages, basePath, translationEngines: settingsTranslationEngines } = require(settingsFilePath);
 
   if (options.engine && !isEngineValid(options.engine)) throw new Error(`You've provided an invalid engine as arg on your CLI Command. Try with one of these: ${validEngines.join(', ')}`);
 

services/translateService.js

@@ -6,6 +6,7 @@ const { translate: libreTranslate } = require("./libreTranslate");
 const {
   getTranslationEnginesToUse,
 } = require("../utils/getTranslationEnginePreferences");
+const { validateLanguageIsSupportedByEngine } = require("../utils/validateLanguageIsSupportedByEngine");
 
 const translateEngines = {
   google: googleTranslate,
@@ -76,18 +77,27 @@ const setTranslateWithFallbackEngines = ({
     );
 
     for await (const engine of enginesFiltered) {
-      await translate(text, from, to, engine)
-        .then(({ text }) => {
-          result = text;
-        })
-        .catch(() => {
-          console.log(
-            `Error translating with ${engine} engine. Trying next engine...`
-          );
-          enginesFailed.push(engine);
-        });
-
-      if (result) break;
+      try {
+        // Validate that the language is supported by the engine to avoid unnecessary network requests
+        validateLanguageIsSupportedByEngine(from, engine);
+        validateLanguageIsSupportedByEngine(to, engine);
+
+        await translate(text, from, to, engine)
+          .then(({ text }) => {
+            result = text;
+            console.log(`Translated successfully with ${engine} engine. Result: ${text}`)
+          })
+          .catch(() => {
+            console.log(
+              `Error translating with ${engine} engine. Trying next engine...`
+            );
+            enginesFailed.push(engine);
+          });
+
+        if (result) break;
+      } catch (error) {
+        console.log(error.message);
+      }
     }
 
     if (!result) {

utils/formatSupportedLanguages.js

@@ -0,0 +1,9 @@
+const getSupportedLanguagesWithNames = (supportedLanguages) => {
+    return Object.entries(supportedLanguages).map(([language, data]) => {
+        return `${language} -> ${data.name}`
+    })
+}
+
+module.exports = {
+    getSupportedLanguagesWithNames
+}

utils/validateLanguageIsSupportedByEngine.js

@@ -0,0 +1,11 @@
+const supportedLanguages = require('../SUPPORTED-LANGUAGES.json');
+
+const validateLanguageIsSupportedByEngine = (requestedLanguage, engine) => {
+    const isLanguageSupportedByEngine = Object.keys(supportedLanguages[requestedLanguage]).includes(engine);
+
+    if (!isLanguageSupportedByEngine) throw new Error(`Language ${requestedLanguage} is not supported by this ${engine}.`);
+
+    return true;
+}
+
+module.exports = { validateLanguageIsSupportedByEngine }

utils/validateLanguageRequested.js

@@ -0,0 +1,23 @@
+const supportedLanguages = require('../SUPPORTED-LANGUAGES.json');
+const { validEngines } = require('../services/translateService');
+const { getSupportedLanguagesWithNames } = require('./formatSupportedLanguages');
+
+const validateLanguageRequested = (requestedLanguage) => {
+    try {
+        if (!requestedLanguage) throw new Error('No language provided.');
+
+        const isLanguageSupported = supportedLanguages[requestedLanguage] !== undefined;
+
+        if (!isLanguageSupported) throw new Error(`Language ${requestedLanguage} is not supported.`);
+
+        const isLanguageSupportedByAlmostOneEngine = Object.keys(supportedLanguages[requestedLanguage]).some(value => validEngines.includes(value));
+
+        if (!isLanguageSupportedByAlmostOneEngine) throw new Error(`Language ${requestedLanguage} is not supported by any engine.`);
+
+        return true;
+    } catch (error) {
+        throw new Error(`${error.message}. \n\nPlease use one of these:\n\n${getSupportedLanguagesWithNames(supportedLanguages).join('\n')}`)
+    }
+}
+
+module.exports = { validateLanguageRequested }