feat: support json filter, closes #192

src/builtin/filters/object.ts

@@ -4,5 +4,8 @@ import { toValue } from '../../util/underscore'
 export default {
   'default': function<T1, T2> (v: string | T1, arg: T2): string | T1 | T2 {
     return isFalsy(toValue(v)) || v === '' ? arg : v
+  },
+  'json': function (v: any) {
+    return JSON.stringify(v)
   }
 }

test/integration/builtin/filters/object.ts

@@ -10,4 +10,10 @@ describe('filters/object', function () {
     it('true should not use default', () => test('{{true | default: "a"}}', 'true'))
     it('0 should not use default', () => test('{{0 | default: "a"}}', '0'))
   })
+  describe('json', function () {
+    it('should stringify string', () => test('{{"foo" | json}}', '"foo"'))
+    it('should stringify number', () => test('{{2 | json}}', '2'))
+    it('should stringify object', () => test('{{obj | json}}', '{"foo":"bar"}'))
+    it('should stringify array', () => test('{{arr | json}}', '[-2,"a"]'))
+  })
 })