fix: math filters now return number, resolves #110

* fix linting
* numbers are no longer fixed:
    i.e. {{0.3 | minus 0.1}} now renders as 0.19999
    Stick to JavaScript number behavior, see: 8.0.0

test/integration/builtin/filters/math.ts

@@ -1,4 +1,5 @@
-import { test } from '../../../stub/render'
+import { expect } from 'chai'
+import { test, liquid } from '../../../stub/render'
 
 describe('filters/math', function () {
   describe('abs', function () {
@@ -35,8 +36,10 @@ describe('filters/math', function () {
   describe('modulo', function () {
     it('should return "1" for 3,2', () => test('{{ 3 | modulo: 2 }}', '1'))
     it('should return "3" for 24,7', () => test('{{ 24 | modulo: 7 }}', '3'))
-    it('should return "3.357" for 183.357,12',
-      () => test('{{ 183.357 | modulo: 12 }}', '3.357'))
+    it('should return "3.357" for 183.357,12', async () => {
+      const html = await liquid.parseAndRender('{{ 183.357 | modulo: 12 }}')
+      expect(Number(html)).to.be.closeTo(3.357, 0.001)
+    })
     it('should convert string', () => test('{{ "24" | modulo: "7" }}', '3'))
   })
   describe('plus', function () {

test/integration/drop/drop.ts

@@ -7,29 +7,29 @@ describe('drop/drop', function () {
 
   class CustomDrop extends Liquid.Types.Drop {
     name: string = 'NAME'
-    getName() {
+    getName () {
       return 'GETNAME'
     }
   }
   class CustomDropWithMethodMissing extends CustomDrop {
-    liquidMethodMissing(key: string) {
+    liquidMethodMissing (key: string) {
       return key.toUpperCase()
     }
   }
   it('should call corresponding method', async function () {
-    const html = await liquid.parseAndRender(`{{obj.getName}}`, {obj: new CustomDrop()})
+    const html = await liquid.parseAndRender(`{{obj.getName}}`, { obj: new CustomDrop() })
     expect(html).to.equal('GETNAME')
   })
   it('should read corresponding property', async function () {
-    const html = await liquid.parseAndRender(`{{obj.name}}`, {obj: new CustomDrop()})
+    const html = await liquid.parseAndRender(`{{obj.name}}`, { obj: new CustomDrop() })
     expect(html).to.equal('NAME')
   })
   it('should output empty string if not exist', async function () {
-    const html = await liquid.parseAndRender(`{{obj.foo}}`, {obj: new CustomDrop()})
+    const html = await liquid.parseAndRender(`{{obj.foo}}`, { obj: new CustomDrop() })
     expect(html).to.equal('')
   })
   it('should respect liquidMethodMissing', async function () {
-    const html = await liquid.parseAndRender(`{{obj.foo}}`, {obj: new CustomDropWithMethodMissing()})
+    const html = await liquid.parseAndRender(`{{obj.foo}}`, { obj: new CustomDropWithMethodMissing() })
     expect(html).to.equal('FOO')
   })
 })

test/integration/liquid/liquid.ts

@@ -1,8 +1,10 @@
 import Liquid from '../../../src/liquid'
 import * as chai from 'chai'
 import { mock, restore } from '../../stub/mockfs'
+import * as chaiAsPromised from 'chai-as-promised'
 
 const expect = chai.expect
+chai.use(chaiAsPromised)
 
 describe('Liquid', function () {
   describe('#plugin()', function () {
@@ -34,6 +36,12 @@ describe('Liquid', function () {
       const html = await engine.parseAndRender(tpl)
       expect(html).to.equal('Welcome(to]Liquid')
     })
+    it('should support for-in with variable', async function () {
+      const src = '{% assign total = 3 | minus: 1 %}' +
+        '{% for i in (1..total) %}{{ i }}{% endfor %}'
+      const html = await engine.parseAndRender(src, {})
+      return expect(html).to.equal('12')
+    })
   })
   describe('#express()', function () {
     const liquid = new Liquid({ root: '/root' })