Add some extended use cases and add specs for all the test cases.

src/defaults.js

@@ -38,7 +38,8 @@ export function get() {
     appendNamespaceToCIMode: false,
     overloadTranslationOptionHandler: function handle(args) {
       var ret = {};
-      if (args[1]) ret.defaultValue = args[1];
+      if (typeof args[1] === 'object') ret = args[1];
+      if (typeof args[1] === 'string') ret.defaultValue = args[1];
       if (typeof args[2] === 'string') ret.tDescription = args[2];
       if (typeof args[2] === 'object' || typeof args[3] === 'object') {
         var options = args[3] || args[2];

test/i18next.defaults.spec.js

@@ -7,6 +7,38 @@ describe('defaults', () => {
     expect(defaults.overloadTranslationOptionHandler(['key', 'my default value'])).to.eql({ defaultValue: 'my default value' });
   });
 
+  it('defaultValue as option', () => {
+    console.log(defaults.overloadTranslationOptionHandler(['key', { defaultValue: 'option default value' }]));
+    expect(defaults.overloadTranslationOptionHandler(['key', { defaultValue: 'option default value' }])).to.eql({ defaultValue: 'option default value' });
+  });
+
+  it('description', () => {
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value', 'the description'])).to.eql({ defaultValue: 'my default value', tDescription: 'the description' });
+  });
+
+  it('description with options defaultValue', () => {
+    // Options overwrites params default value
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value', 'the description'])).to.eql({ defaultValue: 'my default value', tDescription: 'the description' });
+  });
+
+  it('interpolation', () => {
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value {{params}}', {params: 'the value'}])).to.eql({ defaultValue: 'my default value {{params}}', params: 'the value' });
+  });
+
+  it('interpolation with options defaultValue', () => {
+    // Options overwrites params default value
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value {{params}}', {defaultValue: 'options default value', params: 'the value'}])).to.eql({ defaultValue: 'options default value', params: 'the value' });
+  });
+
+  it('interpolation description', () => {
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value {{params}}', 'the description', {params: 'the value'}])).to.eql({ defaultValue: 'my default value {{params}}', params: 'the value', tDescription: 'the description' });
+  });
+
+  it('interpolation description with options defaultValue', () => {
+    // Options overwrites params default value
+    expect(defaults.overloadTranslationOptionHandler(['key', 'my default value {{params}}', 'the description', {defaultValue: 'options default value', params: 'the value'}])).to.eql({ defaultValue: 'options default value', params: 'the value', tDescription: 'the description' });
+  });
+
   it('it should have default format function', () => {
     expect(defaults.interpolation.format('my value', '###', 'de')).to.equal('my value');
   });