feat: promise support for drops, working on #65

test/e2e/eval-value.ts

@@ -5,7 +5,7 @@ describe('.evalValue()', function () {
   var engine: Liquid
   beforeEach(() => { engine = new Liquid() })
 
-  it('should throw when scope undefined', function () {
-    expect(() => engine.evalValue('{{"foo"}}', null as any)).to.throw(/scope undefined/)
+  it('should throw when scope undefined', async function () {
+    return expect(engine.evalValue('{{"foo"}}', null as any)).to.be.rejectedWith(/scope undefined/)
   })
 })

test/integration/builtin/filters/array.ts

@@ -33,9 +33,9 @@ describe('filters/array', function () {
                 ' | split: ", " %}{{ my_array | size }}',
       '4')
     })
-    it('should also be used with dot notation - string',
+    it('should be respected with <string>.size notation',
       () => test('{% assign my_string = "Ground control to Major Tom." %}{{ my_string.size }}', '28'))
-    it('should also be used with dot notation - array',
+    it('should be respected with <array>.size notation',
       () => test('{% assign my_array = "apples, oranges, peaches, plums" | split: ", " %}{{ my_array.size }}', '4'))
   })
   describe('slice', function () {

test/integration/builtin/tags/for.ts

@@ -1,7 +1,7 @@
 import Liquid from '../../../../src/liquid'
 import { expect, use } from 'chai'
 import * as chaiAsPromised from 'chai-as-promised'
-import { Context } from '../../../../src/scope/scope'
+import { Context } from '../../../../src/scope/context'
 
 use(chaiAsPromised)
 

test/integration/drop/drop.ts

@@ -8,7 +8,7 @@ describe('drop/drop', function () {
   class CustomDrop extends Liquid.Types.Drop {
     name: string = 'NAME'
     getName () {
-      return 'GETNAME'
+      return 'GET NAME'
     }
   }
   class CustomDropWithMethodMissing extends CustomDrop {
@@ -16,9 +16,18 @@ describe('drop/drop', function () {
       return key.toUpperCase()
     }
   }
+  class PromiseDrop extends Liquid.Types.Drop {
+    name = Promise.resolve('NAME')
+    async getName () {
+      return 'GET NAME'
+    }
+    async liquidMethodMissing (key: string) {
+      return key.toUpperCase()
+    }
+  }
   it('should call corresponding method', async function () {
     const html = await liquid.parseAndRender(`{{obj.getName}}`, { obj: new CustomDrop() })
-    expect(html).to.equal('GETNAME')
+    expect(html).to.equal('GET NAME')
   })
   it('should read corresponding property', async function () {
     const html = await liquid.parseAndRender(`{{obj.name}}`, { obj: new CustomDrop() })
@@ -32,4 +41,16 @@ describe('drop/drop', function () {
     const html = await liquid.parseAndRender(`{{obj.foo}}`, { obj: new CustomDropWithMethodMissing() })
     expect(html).to.equal('FOO')
   })
+  it('should call corresponding promise method', async function () {
+    const html = await liquid.parseAndRender(`{{obj.getName}}`, { obj: new PromiseDrop() })
+    expect(html).to.equal('GET NAME')
+  })
+  it('should read corresponding promise property', async function () {
+    const html = await liquid.parseAndRender(`{{obj.name}}`, { obj: new PromiseDrop() })
+    expect(html).to.equal('NAME')
+  })
+  it('should support promise returned by liquidMethodMissing', async function () {
+    const html = await liquid.parseAndRender(`{{obj.foo}}`, { obj: new PromiseDrop() })
+    expect(html).to.equal('FOO')
+  })
 })

test/unit/render/syntax.ts

@@ -18,35 +18,35 @@ describe('render/syntax', function () {
   })
 
   describe('.evalValue()', function () {
-    it('should eval boolean literal', function () {
-      expect(evalValue('true', scope)).to.equal(true)
-      expect(evalValue('TrUE', scope)).to.equal(undefined)
-      expect(evalValue('false', scope)).to.equal(false)
+    it('should eval boolean literal', async function () {
+      expect(await evalValue('true', scope)).to.equal(true)
+      expect(await evalValue('TrUE', scope)).to.equal(undefined)
+      expect(await evalValue('false', scope)).to.equal(false)
     })
-    it('should eval number literal', function () {
-      expect(evalValue('2.3', scope)).to.equal(2.3)
-      expect(evalValue('.32', scope)).to.equal(0.32)
-      expect(evalValue('-23.', scope)).to.equal(-23)
-      expect(evalValue('23', scope)).to.equal(23)
+    it('should eval number literal', async function () {
+      expect(await evalValue('2.3', scope)).to.equal(2.3)
+      expect(await evalValue('.32', scope)).to.equal(0.32)
+      expect(await evalValue('-23.', scope)).to.equal(-23)
+      expect(await evalValue('23', scope)).to.equal(23)
     })
-    it('should eval string literal', function () {
-      expect(evalValue('"ab\'c"', scope)).to.equal("ab'c")
-      expect(evalValue("'ab\"c'", scope)).to.equal('ab"c')
+    it('should eval string literal', async function () {
+      expect(await evalValue('"ab\'c"', scope)).to.equal("ab'c")
+      expect(await evalValue("'ab\"c'", scope)).to.equal('ab"c')
     })
-    it('should eval nil literal', function () {
-      expect(evalValue('nil', scope)).to.be.null
+    it('should eval nil literal', async function () {
+      expect(await evalValue('nil', scope)).to.be.null
     })
-    it('should eval null literal', function () {
-      expect(evalValue('null', scope)).to.be.null
+    it('should eval null literal', async function () {
+      expect(await evalValue('null', scope)).to.be.null
     })
-    it('should eval scope variables', function () {
-      expect(evalValue('one', scope)).to.equal(1)
-      expect(evalValue('has_value?', scope)).to.equal(true)
-      expect(evalValue('x', scope)).to.equal('XXX')
+    it('should eval scope variables', async function () {
+      expect(await evalValue('one', scope)).to.equal(1)
+      expect(await evalValue('has_value?', scope)).to.equal(true)
+      expect(await evalValue('x', scope)).to.equal('XXX')
     })
   })
 
-  describe('.isTruthy()', function () {
+  describe('.isTruthy()', async function () {
     // Spec: https://shopify.github.io/liquid/basics/truthy-and-falsy/
     expect(isTruthy(true)).to.be.true
     expect(isTruthy(false)).to.be.false
@@ -61,44 +61,42 @@ describe('render/syntax', function () {
   })
 
   describe('.evalExp()', function () {
-    it('should throw when scope undefined', function () {
-      expect(function () {
-        (evalExp as any)('')
-      }).to.throw(/scope undefined/)
+    it('should throw when scope undefined', async function () {
+      return expect((evalExp as any)('')).to.be.rejectedWith(/scope undefined/)
     })
 
-    it('should eval simple expression', function () {
-      expect(evalExp('1<2', scope)).to.equal(true)
-      expect(evalExp('2<=2', scope)).to.equal(true)
-      expect(evalExp('one<=two', scope)).to.equal(true)
-      expect(evalExp('x contains "x"', scope)).to.equal(false)
-      expect(evalExp('x contains "X"', scope)).to.equal(true)
-      expect(evalExp('1 contains "x"', scope)).to.equal(false)
-      expect(evalExp('y contains "x"', scope)).to.equal(false)
-      expect(evalExp('z contains "x"', scope)).to.equal(false)
-      expect(evalExp('(1..5) contains 3', scope)).to.equal(true)
-      expect(evalExp('(1..5) contains 6', scope)).to.equal(false)
-      expect(evalExp('"<=" == "<="', scope)).to.equal(true)
+    it('should eval simple expression', async function () {
+      expect(await evalExp('1<2', scope)).to.equal(true)
+      expect(await evalExp('2<=2', scope)).to.equal(true)
+      expect(await evalExp('one<=two', scope)).to.equal(true)
+      expect(await evalExp('x contains "x"', scope)).to.equal(false)
+      expect(await evalExp('x contains "X"', scope)).to.equal(true)
+      expect(await evalExp('1 contains "x"', scope)).to.equal(false)
+      expect(await evalExp('y contains "x"', scope)).to.equal(false)
+      expect(await evalExp('z contains "x"', scope)).to.equal(false)
+      expect(await evalExp('(1..5) contains 3', scope)).to.equal(true)
+      expect(await evalExp('(1..5) contains 6', scope)).to.equal(false)
+      expect(await evalExp('"<=" == "<="', scope)).to.equal(true)
     })
 
     describe('complex expression', function () {
-      it('should support value or value', function () {
-        expect(evalExp('false or true', scope)).to.equal(true)
+      it('should support value or value', async function () {
+        expect(await evalExp('false or true', scope)).to.equal(true)
       })
-      it('should support < and contains', function () {
-        expect(evalExp('1<2 and x contains "x"', scope)).to.equal(false)
+      it('should support < and contains', async function () {
+        expect(await evalExp('1<2 and x contains "x"', scope)).to.equal(false)
       })
-      it('should support < or contains', function () {
-        expect(evalExp('1<2 or x contains "x"', scope)).to.equal(true)
+      it('should support < or contains', async function () {
+        expect(await evalExp('1<2 or x contains "x"', scope)).to.equal(true)
       })
-      it('should support value and !=', function () {
-        expect(evalExp('empty and empty != ""', scope)).to.equal(false)
+      it('should support value and !=', async function () {
+        expect(await evalExp('empty and empty != ""', scope)).to.equal(false)
       })
     })
 
-    it('should eval range expression', function () {
-      expect(evalExp('(2..4)', scope)).to.deep.equal([2, 3, 4])
-      expect(evalExp('(two..4)', scope)).to.deep.equal([2, 3, 4])
+    it('should eval range expression', async function () {
+      expect(await evalExp('(2..4)', scope)).to.deep.equal([2, 3, 4])
+      expect(await evalExp('(two..4)', scope)).to.deep.equal([2, 3, 4])
     })
   })
 })

test/unit/scope/scope.ts

@@ -1,5 +1,6 @@
 import * as chai from 'chai'
-import Scope, { Context } from '../../../src/scope/scope'
+import Scope from '../../../src/scope/scope'
+import { Context } from '../../../src/scope/context'
 
 const expect = chai.expect
 
@@ -20,168 +21,156 @@ describe('scope', function () {
   })
 
   describe('#propertyAccessSeq()', function () {
-    it('should handle dot syntax', function () {
-      expect(scope.propertyAccessSeq('foo.bar'))
+    it('should handle dot syntax', async function () {
+      expect(await scope.propertyAccessSeq('foo.bar'))
         .to.deep.equal(['foo', 'bar'])
     })
-    it('should handle [<String>] syntax', function () {
-      expect(scope.propertyAccessSeq('foo["bar"]'))
+    it('should handle [<String>] syntax', async function () {
+      expect(await scope.propertyAccessSeq('foo["bar"]'))
         .to.deep.equal(['foo', 'bar'])
     })
-    it('should handle [<Identifier>] syntax', function () {
-      expect(scope.propertyAccessSeq('foo[foo]'))
+    it('should handle [<Identifier>] syntax', async function () {
+      expect(await scope.propertyAccessSeq('foo[foo]'))
         .to.deep.equal(['foo', 'zoo'])
     })
-    it('should handle nested access 1', function () {
-      expect(scope.propertyAccessSeq('foo[bar.zoo]'))
+    it('should handle nested access 1', async function () {
+      expect(await scope.propertyAccessSeq('foo[bar.zoo]'))
         .to.deep.equal(['foo', 'coo'])
     })
-    it('should handle nested access 2', function () {
-      expect(scope.propertyAccessSeq('foo[bar["zoo"]]'))
+    it('should handle nested access 2', async function () {
+      expect(await scope.propertyAccessSeq('foo[bar["zoo"]]'))
         .to.deep.equal(['foo', 'coo'])
     })
-    it('should handle nested access 3', function () {
-      expect(scope.propertyAccessSeq('bar["foo"].zoo'))
+    it('should handle nested access 3', async function () {
+      expect(await scope.propertyAccessSeq('bar["foo"].zoo'))
         .to.deep.equal(['bar', 'foo', 'zoo'])
     })
-    it('should handle nested access 4', function () {
-      expect(scope.propertyAccessSeq('foo[0].bar'))
+    it('should handle nested access 4', async function () {
+      expect(await scope.propertyAccessSeq('foo[0].bar'))
         .to.deep.equal(['foo', '0', 'bar'])
     })
-    it('should handle nested access 5', function () {
-      expect(scope.propertyAccessSeq('foo[one].bar'))
+    it('should handle nested access 5', async function () {
+      expect(await scope.propertyAccessSeq('foo[one].bar'))
         .to.deep.equal(['foo', '1', 'bar'])
     })
-    it('should handle nested access 6', function () {
-      expect(scope.propertyAccessSeq('foo[two].bar'))
+    it('should handle nested access 6', async function () {
+      expect(await scope.propertyAccessSeq('foo[two].bar'))
         .to.deep.equal(['foo', 'undefined', 'bar'])
     })
   })
 
   describe('#get()', function () {
-    it('should get direct property', function () {
-      expect(scope.get('foo')).equal('zoo')
+    it('should get direct property', async function () {
+      expect(await await scope.get('foo')).equal('zoo')
     })
 
-    it('undefined property should yield undefined', function () {
-      function fn () {
-        scope.get('notdefined')
-      }
-      expect(fn).to.not.throw()
-      expect(scope.get('notdefined')).to.equal(undefined)
-      expect(scope.get(false as any)).to.equal(undefined)
+    it('undefined property should yield undefined', async function () {
+      expect(scope.get('notdefined')).to.be.rejected
+      expect(await scope.get('notdefined')).to.equal(undefined)
+      expect(await scope.get(false as any)).to.equal(undefined)
     })
 
-    it('should throw for invalid path', function () {
-      function fn () {
-        scope.get('')
-      }
-      expect(fn).to.throw('invalid path:""')
+    it('should throw for invalid path', async function () {
+      expect(scope.get('')).to.be.rejectedWith('invalid path:""')
     })
 
-    it('should throw when [] unbalanced', function () {
-      expect(function () {
-        scope.get('foo[bar')
-      }).to.throw(/unbalanced \[\]/)
+    it('should throw when [] unbalanced', async function () {
+      expect(scope.get('foo[bar')).to.be.rejectedWith(/unbalanced \[\]/)
     })
 
-    it('should throw when "" unbalanced', function () {
-      expect(function () {
-        scope.get('foo["bar]')
-      }).to.throw(/unbalanced "/)
+    it('should throw when "" unbalanced', async function () {
+      expect(scope.get('foo["bar]')).to.be.rejectedWith(/unbalanced "/)
     })
 
-    it("should throw when '' unbalanced", function () {
-      expect(function () {
-        scope.get("foo['bar]")
-      }).to.throw(/unbalanced '/)
+    it("should throw when '' unbalanced", async function () {
+      expect(scope.get("foo['bar]")).to.be.rejectedWith(/unbalanced '/)
     })
 
-    it('should respect to to_liquid', function () {
+    it('should respect to to_liquid', async function () {
       const scope = new Scope({ foo: {
         to_liquid: () => ({ bar: 'BAR' }),
         bar: 'bar'
       } })
-      expect(scope.get('foo.bar')).to.equal('BAR')
+      expect(await scope.get('foo.bar')).to.equal('BAR')
     })
 
-    it('should respect to toLiquid', function () {
+    it('should respect to toLiquid', async function () {
       const scope = new Scope({ foo: {
         toLiquid: () => ({ bar: 'BAR' }),
         bar: 'bar'
       } })
-      expect(scope.get('foo.bar')).to.equal('BAR')
+      expect(await scope.get('foo.bar')).to.equal('BAR')
     })
 
-    it('should access child property via dot syntax', function () {
-      expect(scope.get('bar.zoo')).to.equal('coo')
-      expect(scope.get('bar.arr')).to.deep.equal(['a', 'b'])
+    it('should access child property via dot syntax', async function () {
+      expect(await scope.get('bar.zoo')).to.equal('coo')
+      expect(await scope.get('bar.arr')).to.deep.equal(['a', 'b'])
     })
 
-    it('should access child property via [<String>] syntax', function () {
-      expect(scope.get('bar["zoo"]')).to.equal('coo')
+    it('should access child property via [<String>] syntax', async function () {
+      expect(await scope.get('bar["zoo"]')).to.equal('coo')
     })
 
-    it('should access child property via [<Number>] syntax', function () {
-      expect(scope.get('bar.arr[0]')).to.equal('a')
+    it('should access child property via [<Number>] syntax', async function () {
+      expect(await scope.get('bar.arr[0]')).to.equal('a')
     })
 
-    it('should access child property via [<Identifier>] syntax', function () {
-      expect(scope.get('bar[foo]')).to.equal('coo')
+    it('should access child property via [<Identifier>] syntax', async function () {
+      expect(await scope.get('bar[foo]')).to.equal('coo')
     })
 
-    it('should return undefined when not exist', function () {
-      expect(scope.get('foo.foo.foo')).to.be.undefined
+    it('should return undefined when not exist', async function () {
+      expect(await scope.get('foo.foo.foo')).to.be.undefined
     })
-    it('should return string length as size', function () {
-      expect(scope.get('foo.size')).to.equal(3)
+    it('should return string length as size', async function () {
+      expect(await scope.get('foo.size')).to.equal(3)
     })
-    it('should return array length as size', function () {
-      expect(scope.get('bar.arr.size')).to.equal(2)
+    it('should return array length as size', async function () {
+      expect(await scope.get('bar.arr.size')).to.equal(2)
     })
-    it('should return size property if exists', function () {
-      expect(scope.get('zoo.size')).to.equal(4)
+    it('should return size property if exists', async function () {
+      expect(await scope.get('zoo.size')).to.equal(4)
     })
-    it('should return undefined if do not have size and length', function () {
-      expect(scope.get('one.size')).to.equal(undefined)
+    it('should return undefined if do not have size and length', async function () {
+      expect(await scope.get('one.size')).to.equal(undefined)
     })
   })
 
   describe('#set', function () {
-    it('should set nested value', function () {
-      scope.set('posts', {
+    it('should set nested value', async function () {
+      await scope.set('posts', {
         'first': {
           'name': 'A Nice Day'
         }
       })
-      scope.set('category', {
+      await scope.set('category', {
         'diary': ['first']
       })
-      expect(scope.get('posts[category.diary[0]].name'), 'A Nice Day')
+      expect(await scope.get('posts[category.diary[0]].name'), 'A Nice Day')
     })
 
-    it('should create parent if needed', function () {
-      scope.set('a.b.c.d', 'COO')
-      expect(scope.get('a.b.c.d')).to.equal('COO')
+    it('should create parent if needed', async function () {
+      await scope.set('a.b.c.d', 'COO')
+      expect(await scope.get('a.b.c.d')).to.equal('COO')
     })
-    it('should keep other properties of parent', function () {
+    it('should keep other properties of parent', async function () {
       scope.push({ obj: { foo: 'FOO' } })
-      scope.set('obj.bar', 'BAR')
-      expect(scope.get('obj.foo')).to.equal('FOO')
+      await scope.set('obj.bar', 'BAR')
+      expect(await scope.get('obj.foo')).to.equal('FOO')
     })
-    it('should abort if property cannot be set', function () {
+    it('should abort if property cannot be set', async function () {
       scope.push({ obj: { foo: 'FOO' } })
-      scope.set('obj.foo.bar', 'BAR')
-      expect(scope.get('obj.foo')).to.equal('FOO')
+      await scope.set('obj.foo.bar', 'BAR')
+      expect(await scope.get('obj.foo')).to.equal('FOO')
     })
-    it("should set parents' corresponding value", function () {
+    it("should set parents' corresponding value", async function () {
       scope.push({})
-      scope.set('foo', 'bar')
+      await scope.set('foo', 'bar')
       scope.pop()
-      expect(scope.get('foo')).to.equal('bar')
+      expect(await scope.get('foo')).to.equal('bar')
     })
   })
-  describe('strictVariables', function () {
+  describe('strictVariables', async function () {
     let scope: Scope
     beforeEach(function () {
       scope = new Scope(ctx, {
@@ -189,66 +178,57 @@ describe('scope', function () {
       } as any)
     })
     it('should throw when variable not defined', function () {
-      function fn () {
-        scope.get('notdefined')
-      }
-      expect(fn).to.throw(/undefined variable: notdefined/)
+      return expect(scope.get('notdefined')).to.be.rejectedWith(/undefined variable: notdefined/)
     })
-    it('should throw when deep variable not exist', function () {
-      scope.set('foo', 'FOO')
-      function fn () {
-        scope.get('foo.bar.not.defined')
-      }
-      expect(fn).to.throw(/undefined variable: bar/)
+    it('should throw when deep variable not exist', async function () {
+      await scope.set('foo', 'FOO')
+      return expect(scope.get('foo.bar.not.defined')).to.be.rejectedWith(/undefined variable: bar/)
     })
-    it('should throw when itself not defined', function () {
-      scope.set('foo', 'bar')
-      function fn () {
-        scope.get('foo.BAR')
-      }
-      expect(fn).to.throw(/undefined variable: BAR/)
+    it('should throw when itself not defined', async function () {
+      await scope.set('foo', 'bar')
+      return expect(scope.get('foo.BAR')).to.be.rejectedWith(/undefined variable: BAR/)
     })
-    it('should find variable in parent scope', function () {
-      scope.set('foo', 'foo')
+    it('should find variable in parent scope', async function () {
+      await scope.set('foo', 'foo')
       scope.push({
         'bar': 'bar'
       })
-      expect(scope.get('foo')).to.equal('foo')
+      expect(await scope.get('foo')).to.equal('foo')
     })
   })
 
   describe('.getAll()', function () {
-    it('should get all properties when arguments empty', function () {
-      expect(scope.getAll()).deep.equal(ctx)
+    it('should get all properties when arguments empty', async function () {
+      expect(await scope.getAll()).deep.equal(ctx)
     })
   })
 
   describe('.push()', function () {
-    it('should push scope', function () {
-      scope.set('bar', 'bar')
+    it('should push scope', async function () {
+      await scope.set('bar', 'bar')
       scope.push({
         foo: 'foo'
       })
-      expect(scope.get('foo')).to.equal('foo')
-      expect(scope.get('bar')).to.equal('bar')
+      expect(await scope.get('foo')).to.equal('foo')
+      expect(await scope.get('bar')).to.equal('bar')
     })
-    it('should hide deep properties by push', function () {
-      scope.set('bar', { bar: 'bar' })
+    it('should hide deep properties by push', async function () {
+      await scope.set('bar', { bar: 'bar' })
       scope.push({ bar: { foo: 'foo' } })
-      expect(scope.get('bar.foo')).to.equal('foo')
-      expect(scope.get('bar.bar')).to.equal(undefined)
+      expect(await scope.get('bar.foo')).to.equal('foo')
+      expect(await scope.get('bar.bar')).to.equal(undefined)
     })
   })
   describe('.pop()', function () {
-    it('should pop scope', function () {
+    it('should pop scope', async function () {
       scope.push({
         foo: 'foo'
       })
       scope.pop()
-      expect(scope.get('foo')).to.equal('zoo')
+      expect(await scope.get('foo')).to.equal('zoo')
     })
   })
-  it('should pop specified scope', function () {
+  it('should pop specified scope', async function () {
     const scope1 = {
       foo: 'foo'
     }
@@ -257,11 +237,11 @@ describe('scope', function () {
     }
     scope.push(scope1)
     scope.push(scope2)
-    expect(scope.get('foo')).to.equal('foo')
-    expect(scope.get('bar')).to.equal('bar')
+    expect(await scope.get('foo')).to.equal('foo')
+    expect(await scope.get('bar')).to.equal('bar')
     scope.pop(scope1)
-    expect(scope.get('foo')).to.equal('zoo')
-    expect(scope.get('bar')).to.equal('bar')
+    expect(await scope.get('foo')).to.equal('zoo')
+    expect(await scope.get('bar')).to.equal('bar')
   })
   it('should throw when specified scope not found', function () {
     const scope1 = {

test/unit/template/filter/filter.ts

@@ -13,34 +13,34 @@ describe('filter', function () {
     Filter.clear()
     scope = new Scope()
   })
-  it('should create default filter if not registered', function () {
+  it('should create default filter if not registered', async function () {
     const result = new Filter('foo', [], false)
     expect(result.name).to.equal('foo')
   })
 
-  it('should render input if filter not registered', function () {
-    expect(new Filter('undefined', [], false).render('foo', scope)).to.equal('foo')
+  it('should render input if filter not registered', async function () {
+    expect(await new Filter('undefined', [], false).render('foo', scope)).to.equal('foo')
   })
 
-  it('should call filter impl with corrct arguments', function () {
+  it('should call filter impl with corrct arguments', async function () {
     const spy = sinon.spy()
     Filter.register('foo', spy)
-    new Filter('foo', ['33'], false).render('foo', scope)
+    await new Filter('foo', ['33'], false).render('foo', scope)
     expect(spy).to.have.been.calledWith('foo', 33)
   })
-  it('should render a simple filter', function () {
+  it('should render a simple filter', async function () {
     Filter.register('upcase', x => x.toUpperCase())
-    expect(new Filter('upcase', [], false).render('foo', scope)).to.equal('FOO')
+    expect(await new Filter('upcase', [], false).render('foo', scope)).to.equal('FOO')
   })
 
-  it('should render filters with argument', function () {
+  it('should render filters with argument', async function () {
     Filter.register('add', (a, b) => a + b)
-    expect(new Filter('add', ['2'], false).render(3, scope)).to.equal(5)
+    expect(await new Filter('add', ['2'], false).render(3, scope)).to.equal(5)
   })
 
-  it('should render filters with multiple arguments', function () {
+  it('should render filters with multiple arguments', async function () {
     Filter.register('add', (a, b, c) => a + b + c)
-    expect(new Filter('add', ['2', '"c"'], false).render(3, scope)).to.equal('5c')
+    expect(await new Filter('add', ['2', '"c"'], false).render(3, scope)).to.equal('5c')
   })
 
   it('should not throw when filter name illegal', function () {

test/unit/template/value.ts

@@ -99,7 +99,7 @@ describe('Value', function () {
   })
 
   describe('#value()', function () {
-    it('should call chained filters correctly', function () {
+    it('should call chained filters correctly', async function () {
       const date = sinon.stub().returns('y')
       const time = sinon.spy()
       Filter.register('date', date)
@@ -108,7 +108,7 @@ describe('Value', function () {
       const scope = new Scope({
         foo: { bar: 'bar' }
       })
-      tpl.value(scope)
+      await tpl.value(scope)
       expect(date).to.have.been.calledWith('bar', 'b')
       expect(time).to.have.been.calledWith('y', 2)
     })