feat(logger): initOptions.debugOptionsFilter

src/i18next.js

@@ -193,7 +193,12 @@ class I18n extends EventEmitter {
         this.isInitializing = false;
         if (this.isInitialized && !this.initializedStoreOnce) this.logger.warn('init: i18next is already initialized. You should call init just once!');
         this.isInitialized = true;
-        if (!this.options.isClone) this.logger.log('initialized', this.options);
+        if (!this.options.isClone) {
+          this.logger.log(
+            'initialized',
+            typeof this.options.debugOptionsFilter === 'function' ? this.options.debugOptionsFilter(this.options) : this.options
+          );
+        }
         this.emit('initialized', this.options);
 
         deferred.resolve(t); // not rejecting on err (as err is only a loading translation failed warning)

test/runtime/i18next.debug.test.js

@@ -0,0 +1,21 @@
+import { describe, it, expect, beforeAll, vi } from 'vitest';
+import i18next from '../../src/i18next.js';
+import logger from '../../src/logger.js';
+
+describe('i18next debug', () => {
+  let logSpy;
+  beforeAll(async () => {
+    logSpy = vi.spyOn(logger, 'log');
+    await i18next.init({
+      foo: 'bar',
+      debug: true,
+    });
+    i18next.changeLanguage('en');
+  });
+
+  describe('init log options filtering', () => {
+    it('logs a subset of the options object', () => {
+      expect(logSpy).toHaveBeenCalledWith('initialized', i18next.options);
+    });
+  });
+});

test/runtime/i18next.debugFilter.test.js

@@ -0,0 +1,22 @@
+import { describe, it, expect, beforeAll, vi } from 'vitest';
+import i18next from '../../src/i18next.js';
+import logger from '../../src/logger.js';
+
+describe('i18next debug', () => {
+  let logSpy;
+  beforeAll(async () => {
+    logSpy = vi.spyOn(logger, 'log');
+    await i18next.init({
+      foo: 'bar',
+      debug: true,
+      debugOptionsFilter: (opt) => ({ namespaces: opt.ns.length }),
+    });
+    i18next.changeLanguage('en');
+  });
+
+  describe('init log options filtering', () => {
+    it('logs a subset of the options object', () => {
+      expect(logSpy).toHaveBeenCalledWith('initialized', { namespaces: 1 });
+    });
+  });
+});

typescript/options.d.ts

@@ -350,6 +350,12 @@ export interface InitOptions<T = object> extends PluginOptions<T> {
    */
   debug?: boolean;
 
+  /**
+   * Filter function that allows changing the logged option value when `debug` is set to true.
+   * @default undefined
+   */
+  debugOptionsFilter?: (options: InitOptions<T>) => unknown;
+
   /**
    * Resources to initialize with (if not using loading or not appending using addResourceBundle)
    * @default undefined