STRF-9124 Create an endpoint for precaching lang helper function

bigcommerce · May 18, 2021 · 42055bd · 42055bd
1 parent e75dac2
commit 42055bd
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Showing 4 changed files with 76 additions and 8 deletions.
diff --git a/index.js b/index.js
@@ -289,6 +289,15 @@ class Paper {
     addTemplates(templates) {
         this.renderer.addTemplates(templates);
     }
+
+    /**
+     * Precompiles translations to string representations of translation function source code 
+     * 
+     * @param {Object} translations transformed translations object 
+     */
+    precompileTranslations(translations) {
+        return Translator.precompileTranslations(translations);
+    }
 }
 
 module.exports = Paper;
diff --git a/lib/translator/filter.js b/lib/translator/filter.js
@@ -26,7 +26,7 @@ function filterByKey(language, keyFilter) {
                     result[key][subKey] = language[key][subKey];
                 }
             }
-        } else {
+        } else if (key !== 'compiledTranslations') {
             result[key] = language[key];
         }
     }

diff --git a/lib/translator/index.js b/lib/translator/index.js
@@ -26,19 +26,16 @@ const DEFAULT_LOCALE = 'en';
  */
 function Translator(acceptLanguage, allTranslations, logger = console, omitTransforming = false) {
     this.logger = logger;
+    this.omitTransforming = omitTransforming;
 
-    const languages = omitTransforming ? allTranslations : Transformer.transform(allTranslations, DEFAULT_LOCALE, this.logger);
+    const languages = this.omitTransforming ? allTranslations : Transformer.transform(allTranslations, DEFAULT_LOCALE, this.logger);
     /**
      * @private
      * @type {string}
      */
     this._locale = LocaleParser.getPreferredLocale(acceptLanguage, languages, DEFAULT_LOCALE);
 
-    /**
-     * @private
-     * @type {Object.<string, string>}
-     */
-    this._language = languages[this._locale] || {};
+    this.setLanguage(languages);
 
     /**
      * @private
@@ -66,6 +63,53 @@ Translator.create = function (acceptLanguage, allTranslations, logger = console,
     return new Translator(acceptLanguage, allTranslations, logger, omitTransforming);
 };
 
+/**
+ * Precompile translation functions
+ * @param {Object} translations
+ * @returns {Object}
+ */
+ Translator.precompileTranslations = function (translations) {
+    const compiled = {};
+
+    Object.keys(translations).forEach(language => {
+        compiled[language] = {}
+        Object.keys(translations[language]).forEach(categoryKey => {
+            compiled[language][categoryKey] = translations[language][categoryKey];
+            if (categoryKey === 'translations') {
+                compiled[language].compiledTranslations = {};
+                Object.keys(translations[language][categoryKey]).forEach(key => {
+                    compiled[language].compiledTranslations[key] = Translator.compileFormatterFunction(translations[language], key);
+                })
+            }
+        });
+    });
+
+    return compiled;
+}
+
+/**
+ * Precompile translation functions
+ * @param {Object} language
+ * @param {String} key
+ * @returns {Object}
+ */
+Translator.compileFormatterFunction = function (language, key) {
+    const locale = language.locales[key];
+    const formatter = new MessageFormat(locale)
+
+    try {
+        return formatter.compile(language.translations[key]).toString();
+    } catch (err) {
+        if (err.name === 'SyntaxError') {
+            this.logger.error(`Syntax Error during Formatter function precompilation: ${err.message} for key "${key}"`, err.expected);
+
+            return () => '';
+        }
+
+        throw err;
+    }
+}
+
 /**
  * Get translated string
  * @param {string} key
@@ -78,11 +122,16 @@ Translator.prototype.translate = function (key, parameters) {
         return key;
     }
 
-    if (typeof this._formatFunctions[key] === 'undefined') {
+    if (!this.omitTransforming && typeof this._formatFunctions[key] === 'undefined') {
         this._formatFunctions[key] = this._compileTemplate(key);
     }
 
     try {
+        if (this.omitTransforming) {
+            const fn = new Function(`return ${language.compiledTranslations[key]}`)()
+            return fn(parameters);
+        }
+
         return this._formatFunctions[key](parameters);
     } catch (err) {
         this.logger.error(err);
@@ -112,6 +161,14 @@ Translator.prototype.getLanguage = function (keyFilter) {
     return this._language;
 };
 
+/**
+ * Set language object
+ * @param {Object} [languages] object
+ */
+Translator.prototype.setLanguage = function (languages) {
+    this._language = languages[this._locale] || {};
+};
+
 /**
  * Get formatter
  * @private

diff --git a/spec/lib/translator.js b/spec/lib/translator.js
@@ -303,6 +303,8 @@ describe('Translator', () => {
         it('should successfully translate en language without transforming translations', done => {
             const locale = 'en';
             const translator = Translator.create(locale, flattenedLanguages, console, true);
+            const precompiledTranslations = Translator.precompileTranslations(flattenedLanguages);
+            translator.setLanguage(precompiledTranslations)
             expect(translator.translate('hello', {name: 'User'})).to.equal('Hello User');
 
             const key = 'level1.level2';