⚡ improvement(named): using default use nmae when value is missing

src/format.js

@@ -21,6 +21,8 @@ export default function (Vue) {
   function template (string, ...args) {
     if (args.length === 1 && typeof args[0] === 'object') {
       args = args[0]
+    } else {
+      args = {}
     }
 
     if (!args || !args.hasOwnProperty) {
@@ -34,9 +36,9 @@ export default function (Vue) {
         && string[index + match.length] === '}') {
         return i
       } else {
-        result = hasOwn(args, i) ? args[i] : null
+        result = hasOwn(args, i) ? args[i] : match
         if (result === null || result === undefined) {
-          return match
+          return ''
         }
 
         return result

test/specs/format.js

@@ -8,18 +8,31 @@ const format = Format(Vue)
 describe('format', () => {
   describe('argument', () => {
     context('Object', () => {
-      it('should be replace with object value', () => {
-        const template = 'name: {name}, email: {email}'
-        assert.equal(format(template, {
-          name: 'kazupon', email: '[email protected]'
-        }), 'name: kazupon, email: [email protected]')
+      context('default delimiter', () => {
+        it('should be replace with object value', () => {
+          const template = 'name: {name}, email: {email}'
+          assert.equal(format(template, {
+            name: 'kazupon', email: '[email protected]'
+          }), 'name: kazupon, email: [email protected]')
+        })
       })
 
-      it('should be replace with object value', () => {
-        const template = 'name: %{name}, email: %{email}'
-        assert.equal(format(template, {
-          name: 'kazupon', email: '[email protected]'
-        }), 'name: kazupon, email: [email protected]')
+      context('RoR delimiter', () => {
+        it('should be replace with object value', () => {
+          const template = 'name: %{name}, email: %{email}'
+          assert.equal(format(template, {
+            name: 'kazupon', email: '[email protected]'
+          }), 'name: kazupon, email: [email protected]')
+        })
+      })
+
+      context('missing', () => {
+        it('should be replace with as is', () => {
+          const template = 'name: {name}, email: {email}'
+          assert.equal(format(template, {
+            name: 'kazupon'
+          }), 'name: kazupon, email: {email}')
+        })
       })
     })
 
@@ -36,21 +49,21 @@ describe('format', () => {
     context('null', () => {
       it('should be replace with empty', () => {
         const template = 'name: {0}, email: {1}'
-        assert.equal(format(template, null), 'name: , email: ')
+        assert.equal(format(template, null), 'name: {0}, email: {1}')
       })
     })
 
     context('undefined', () => {
       it('should be replace with empty', () => {
         const template = 'name: {0}, email: {1}'
-        assert.equal(format(template, undefined), 'name: , email: ')
+        assert.equal(format(template, undefined), 'name: {0}, email: {1}')
       })
     })
 
     context('not specify', () => {
       it('should be replace with empty', () => {
         const template = 'name: {0}, email: {1}'
-        assert.equal(format(template), 'name: , email: ')
+        assert.equal(format(template), 'name: {0}, email: {1}')
       })
     })
   })