feature: variable lookup respects to to_liquid, #81

src/scope.js

@@ -58,12 +58,17 @@ var Scope = {
   },
   readProperty: function (obj, key) {
     let val
-    if (key === 'size' && (_.isArray(obj) || _.isString(obj))) {
+    if (_.isNil(obj)) {
-      val = obj.length
-    } else if (_.isNil(obj)) {
       val = undefined
     } else {
-      val = obj[key]
+      if (typeof obj.to_liquid === 'function') {
+        obj = obj.to_liquid()
+      }
+      if (key === 'size' && (_.isArray(obj) || _.isString(obj))) {
+        val = obj.length
+      } else {
+        val = obj[key]
+      }
     }
     if (_.isNil(val) && this.opts.strict_variables) {
       throw new TypeError(`undefined variable: ${key}`)

src/util/underscore.js

@@ -1,3 +1,4 @@
+'use strict'
 const toStr = Object.prototype.toString
 
 /*
@@ -10,12 +11,12 @@ function isString (value) {
 }
 
 function stringify (value) {
+  if (value && typeof value.to_liquid === 'function') {
+    return stringify(value.to_liquid())
+  }
   if (isString(value)) {
     return value
   }
-  if (value && typeof value.to_liquid === 'function') {
-    return value.to_liquid()
-  }
 
   let cache = []
   return JSON.stringify(value, (key, value) => {

test/render.js

@@ -1,3 +1,4 @@
+'use strict'
 const chai = require('chai')
 const chaiAsPromised = require('chai-as-promised')
 const expect = chai.expect
@@ -42,7 +43,6 @@ describe('render', function () {
       let tpl = Template.parseValue('bar')
       return expect(render.renderValue(tpl, scope)).to.eventually.equal('custom')
     })
-
     it('should stringify objects', function () {
       let scope = Scope.factory({
         foo: { obj: { arr: ['a', 2] } }
@@ -65,20 +65,6 @@ describe('render', function () {
     })
   })
 
-  it('should eval filter with correct arguments', function () {
-    let date = sinon.stub().returns('y')
-    let time = sinon.spy()
-    filter.register('date', date)
-    filter.register('time', time)
-    let tpl = Template.parseValue('foo.bar | date: "b" | time:2')
-    let scope = Scope.factory({
-      foo: {bar: 'bar'}
-    })
-    render.evalValue(tpl, scope)
-    expect(date).to.have.been.calledWith('bar', 'b')
-    expect(time).to.have.been.calledWith('y', 2)
-  })
-
   describe('.evalValue()', function () {
     it('should throw when scope undefined', function () {
       expect(function () {
@@ -99,5 +85,18 @@ describe('render', function () {
       let tpl = Template.parseValue('"x" | arr')
       expect(render.evalValue(tpl, Scope.factory())).to.deep.equal([1])
     })
+    it('should eval filter with correct arguments', function () {
+      let date = sinon.stub().returns('y')
+      let time = sinon.spy()
+      filter.register('date', date)
+      filter.register('time', time)
+      let tpl = Template.parseValue('foo.bar | date: "b" | time:2')
+      let scope = Scope.factory({
+        foo: {bar: 'bar'}
+      })
+      render.evalValue(tpl, scope)
+      expect(date).to.have.been.calledWith('bar', 'b')
+      expect(time).to.have.been.calledWith('y', 2)
+    })
   })
 })

test/scope.js

@@ -88,6 +88,14 @@ describe('scope', function () {
       }).to.throw(/unbalanced '/)
     })
 
+    it('should respect to to_liquid', function () {
+      let scope = Scope.factory({foo: {
+        to_liquid: () => ({bar: 'BAR'}),
+        bar: 'bar'
+      }})
+      expect(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'])