feat: export isVNode function

groupon · Oct 30, 2019 · 4282d73 · 4282d73
1 parent 26e779f
commit 4282d73
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Showing 3 changed files with 31 additions and 5 deletions.
diff --git a/lib/phy.js b/lib/phy.js
@@ -43,14 +43,26 @@ const preact = require('preact');
 // VNode props https://github.com/preactjs/preact/blob/master/src/index.d.ts#L14-L17
 const VNODE_ATTRS = ['props', 'type', 'key', 'ref'];
 
+/** @param {object} obj
+ *  @returns {boolean}
+ */
+function isPreactNode(obj) {
+  if (!obj) {
+    return false;
+  }
+  return VNODE_ATTRS.every(prop =>
+    Object.prototype.hasOwnProperty.call(obj, prop)
+  );
+}
+
 const objectToString = Object.toString();
 
 /** @param {VNode | Readonly<Record<string, any>>} obj */
 function isAttributes(obj) {
   return (
     'object' === typeof obj &&
     (!obj.constructor || obj.constructor.toString() === objectToString) &&
-    !VNODE_ATTRS.every(prop => Object.prototype.hasOwnProperty.call(obj, prop))
+    !isPreactNode(obj)
   );
 }
 
@@ -102,5 +114,6 @@ function h(createElement, selector, attrs, ...kids) {
 module.exports = exports = h.bind(null, preact.createElement);
 
 exports.h = exports;
+exports.isVNode = isPreactNode;
 exports.Component = preact.Component;
 exports.render = preact.render;
diff --git a/lib/typedefs.d.ts b/lib/typedefs.d.ts
@@ -1,6 +1,8 @@
 import { Component, ComponentChildren, ComponentType, VNode } from 'preact';
 import p from 'preact';
 
+declare function isPreactNode(obj: object): boolean;
+
 declare function phy(
   selectorOrComp: string | ComponentType,
   ...kids: ComponentChildren[]
@@ -15,6 +17,7 @@ declare namespace phy {
   let h: typeof phy;
   let Component: typeof p.Component;
   let render: typeof p.render;
+  let isVNode: typeof isPreactNode;
 }
 
 export = phy;
diff --git a/test/phy.test.js b/test/phy.test.js
@@ -2,7 +2,7 @@
 
 const assert = require('assertive');
 
-const h = require('../');
+const { h, isVNode } = require('../');
 const { Fragment } = require('preact');
 const render = require('preact-render-to-string');
 
@@ -96,9 +96,19 @@ const tests = [
 ];
 
 describe('phy', () => {
-  tests.forEach(test => {
-    it(test[0], () => {
-      assert.equal(test[2], render(test[1]));
+  describe('h', () => {
+    tests.forEach(test => {
+      it(test[0], () => {
+        assert.equal(test[2], render(test[1]));
+      });
     });
   });
+
+  describe('isVNode', () => {
+    it('should evaluate to "true" for a VNode', () =>
+      assert.expect(isVNode(h('div'))));
+
+    it('should evaluate to "false" for non VNodes', () =>
+      [null, undefined, {}, 1].forEach(test => assert.falsey(isVNode(test))));
+  });
 });