xml: ignore false children

packages/xml/lib/x.js

@@ -3,11 +3,12 @@
 const Element = require('./Element')
 
 function append(el, child) {
+  if (child === false || child === null || child === undefined) return
   if (child instanceof Element) {
     el.append(child)
   } else if (Array.isArray(child)) {
     child.forEach(c => append(el, c))
-  } else if (child !== null && child !== undefined) {
+  } else {
     el.append(String(child))
   }
 }

packages/xml/test/Element.js

@@ -3,7 +3,8 @@
 const test = require('ava')
 const Element = require('../lib/Element')
 
-test('ignore __self and __source properties', t => {
+// TODO probably better to ignore in serialization instead
+test('ignore __self and __source attributes', t => {
   const el = new Element('foo', {
     __source: 'source',
     __self: 'self',

packages/xml/test/x.js

@@ -0,0 +1,22 @@
+'use strict'
+
+const test = require('ava')
+const x = require('../lib/x')
+
+test('ignore false children', t => {
+  const el = x('foo', {}, false)
+
+  t.is(el.children.length, 0)
+})
+
+test('ignore null children', t => {
+  const el = x('foo', {}, null)
+
+  t.is(el.children.length, 0)
+})
+
+test('ignore undefined children', t => {
+  const el = x('foo', {}, undefined)
+
+  t.is(el.children.length, 0)
+})