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

.eslintrc.json

@@ -18,6 +18,6 @@
     "prefer-const": 2,
     "no-unused-vars": "off",
     "import/export": "off",
-    "@typescript-eslint/no-unused-vars": ["error", { "vars": "all", "args": "off", "ignoreRestSiblings": false }]
+    "@typescript-eslint/no-unused-vars": ["error", { "vars": "all", "args": "none", "ignoreRestSiblings": false }]
   }
 }

src/builtin/filters/math.ts

@@ -3,24 +3,12 @@ export default {
   'ceil': (v: number) => Math.ceil(v),
   'divided_by': (v: number, arg: number) => v / arg,
   'floor': (v: number) => Math.floor(v),
-  'minus': bindFixed((v: number, arg: number) => v - arg),
-  'modulo': bindFixed((v: number, arg: number) => v % arg),
+  'minus': (v: number, arg: number) => v - arg,
+  'modulo': (v: number, arg: number) => v % arg,
   'round': (v: number, arg: number = 0) => {
     const amp = Math.pow(10, arg)
     return Math.round(v * amp) / amp
   },
-  'plus': bindFixed((v: number, arg: number) => Number(v) + Number(arg)),
+  'plus': (v: number, arg: number) => Number(v) + Number(arg),
   'times': (v: number, arg: number) => v * arg
 }
-
-function getFixed (v: number) {
-  const p = String(v).split('.')
-  return (p.length > 1) ? p[1].length : 0
-}
-
-function bindFixed (cb: (v: number, arg: number) => number) {
-  return (l: number, r: number) => {
-    const f = Math.max(getFixed(l), getFixed(r))
-    return cb(l, r).toFixed(f)
-  }
-}

src/drop/drop.ts

@@ -1,7 +1,5 @@
-import { deprecate } from '../util/deprecate'
-
 export abstract class Drop {
-  valueOf(): any {
+  valueOf (): any {
     return undefined
   }
 

src/render/syntax.ts

@@ -64,8 +64,8 @@ export function parseExp (exp: string, scope: Scope): any {
   }
 
   if ((match = exp.match(lexical.rangeLine))) {
-    const low = parseValue(match[1], scope)
-    const high = parseValue(match[2], scope)
+    const low = evalValue(match[1], scope)
+    const high = evalValue(match[2], scope)
     return range(low, high + 1)
   }
 

src/util/deprecate.ts

@@ -1,7 +1,7 @@
 const reported:{[key: string]: boolean} = {}
 
-export function deprecate(msg: string, issue: number) {
+export function deprecate (msg: string, issue: number) {
   if (reported[msg]) return
   console.warn(msg + ` See: https://github.com/harttle/liquidjs/issues/${issue}`)
   reported[msg] = true
-}
+}

src/util/underscore.ts

@@ -96,21 +96,7 @@ export function isObject (value: any): value is object {
   return value !== null && (type === 'object' || type === 'function')
 }
 
-/*
- * A function to create flexibly-numbered lists of integers,
- * handy for each and map loops. start, if omitted, defaults to 0; step defaults to 1.
- * Returns a list of integers from start (inclusive) to stop (exclusive),
- * incremented (or decremented) by step, exclusive.
- * Note that ranges that stop before they start are considered to be zero-length instead of
- * negative — if you'd like a negative range, use a negative step.
- */
-export function range (start: number, stop?: number, step?: number) {
-  if (stop === undefined) {
-    stop = start
-    start = 0
-  }
-  step = step || 1
-
+export function range (start: number, stop: number, step: number = 1) {
   const arr: number[] = []
   for (let i = start; i < stop; i += step) {
     arr.push(i)

test/e2e/drop.ts

@@ -6,10 +6,10 @@ use(chaiAsPromised)
 
 class SettingsDrop extends Liquid.Types.Drop {
   foo: string = 'FOO'
-  bar() {
+  bar () {
     return 'BAR'
   }
-  liquidMethodMissing(key: string) {
+  liquidMethodMissing (key: string) {
     return key.toUpperCase()
   }
 }
@@ -21,7 +21,6 @@ describe('drop', function () {
     engine = new Liquid()
   })
   it('should support liquidMethodMissing', async function () {
-    let i = 0
     const src = `{{settings.foo}},{{settings.bar}},{{settings.coo}}`
     const html = await engine.parseAndRender(src, { settings })
     return expect(html).to.equal('FOO,BAR,COO')

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' })

test/stub/render.ts

@@ -1,7 +1,7 @@
 import Liquid from '../../src/liquid'
 import { expect } from 'chai'
 
-const liquid = new Liquid()
+export const liquid = new Liquid()
 
 export const ctx = {
   date: new Date(),

test/unit/util/underscore.ts

@@ -81,9 +81,6 @@ describe('util/underscore', function () {
     it('should return a range of integers', function () {
       expect(_.range(3, 5)).to.deep.equal([3, 4])
     })
-    it('should start from 0 if begin omitted', function () {
-      expect(_.range(3)).to.deep.equal([0, 1, 2])
-    })
   })
   describe('.isObject()', function () {
     it('should return true for function', function () {