Added jsTruthy flag to constuctor in order to enable JS style truthiness evaluation

test/unit/render/boolean.ts

@@ -1,7 +1,7 @@
-import { isTruthy } from '../../../src/render/boolean'
+import { isTruthy, isFalsy } from '../../../src/render/boolean'
 import { expect } from 'chai'
 
-describe('boolean', async function () {
+describe('boolean Shopify', async function () {
   describe('.isTruthy()', async function () {
     // Spec: https://shopify.github.io/liquid/basics/truthy-and-falsy/
     it('true is truthy', function () {
@@ -36,3 +36,53 @@ describe('boolean', async function () {
     })
   })
 })
+
+describe('boolean jsTruthy', async function () {
+  const ctx = {
+    opts: {
+      jsTruthy: true
+    }
+  }
+
+  describe('.isFalsy()', async function () {
+    it('null is always falsy', function () {
+      expect(isFalsy(null, ctx)).to.be.false
+    })
+  })
+
+  describe('.isTruthy()', async function () {
+    it('true is truthy', function () {
+      expect(isTruthy(true, ctx)).to.be.true
+    })
+    it('false is falsy', function () {
+      expect(isTruthy(false, ctx)).to.be.false
+    })
+    it('null is always falsy', function () {
+      expect(isTruthy(null, ctx)).to.be.false
+    })
+    it('null is always falsy', function () {
+      expect(isTruthy(null, ctx)).to.be.false
+    })
+    it('"foo" is truthy', function () {
+      expect(isTruthy('foo', ctx)).to.be.true
+    })
+    it('"" is falsy', function () {
+      expect(isTruthy('', ctx)).to.be.false
+    })
+    it('0 is falsy', function () {
+      expect(isTruthy(0, ctx)).to.be.false
+    })
+    it('1 is truthy', function () {
+      expect(isTruthy(1, ctx)).to.be.true
+    })
+    it('1.1 is truthy', function () {
+      expect(isTruthy(1.1, ctx)).to.be.true
+    })
+    it('[1] is truthy', function () {
+      expect(isTruthy([1], ctx)).to.be.true
+    })
+    it('[] is falsy', function () {
+      expect(isTruthy([], ctx)).to.be.false
+    })
+  })
+})