fix: getQueriesForElement always binds

Author: patrickhulce

lib/extend.ts

@@ -1,5 +1,6 @@
 import {Matcher, MatcherOptions, SelectorMatcherOptions} from 'dom-testing-library/typings' // tslint:disable-line no-submodule-imports
 import {getDocument, getQueriesForElement} from '.'
+import {ElementHandle} from '../node_modules/@types/puppeteer'
 
 // tslint:disable-next-line
 let Page, ElementHandle
@@ -9,7 +10,13 @@ try {
   ElementHandle = require('puppeteer/lib/ElementHandle.js') // tslint:disable-line
 
   Page.prototype.getDocument = getDocument
-  getQueriesForElement(ElementHandle.prototype)
+  getQueriesForElement(ElementHandle.prototype, function(this: ElementHandle): ElementHandle {
+    return this
+  })
+
+  ElementHandle.prototype.getQueriesForElement = function(this: ElementHandle): ElementHandle {
+    return getQueriesForElement(this)
+  }
 } catch (err) {
   // tslint:disable-next-line
   console.error('Could not augment puppeteer functions, do you have a conflicting version?')

lib/index.ts

@@ -118,11 +118,8 @@ export function wait(
 
 export function getQueriesForElement<T>(object: T, contextFn?: ContextFn): T & IQueryUtils {
   const o = object as any
-  o.getQueriesForElement = function() {
-    const realContextFn = contextFn || ((): ElementHandle => this)
-    return getQueriesForElement(this, realContextFn)
-  }
-
+  if (!contextFn) contextFn = () => o
+  o.getQueriesForElement = () => getQueriesForElement(o, () => o)
   o.queryByPlaceholderText = createDelegateFor('queryByPlaceholderText', contextFn)
   o.queryAllByPlaceholderText = createDelegateFor('queryAllByPlaceholderText', contextFn)
   o.getByPlaceholderText = createDelegateFor('getByPlaceholderText', contextFn)

test/index.test.ts

@@ -1,6 +1,6 @@
 import * as path from 'path'
 import * as puppeteer from 'puppeteer'
-import {getDocument, queries} from '../lib'
+import {getDocument, queries, getQueriesForElement} from '../lib'
 
 describe('lib/index.ts', () => {
   let browser: puppeteer.Browser
@@ -15,7 +15,13 @@ describe('lib/index.ts', () => {
   it('should export the utilities', async () => {
     const document = await getDocument(page)
     const element = await queries.getByText(document, 'Hello h1')
-    expect(await page.evaluate(el => el.textContent, element)).toEqual('Hello h1')
+    expect(await queries.getNodeText(element)).toEqual('Hello h1')
+  })
+
+  it('should bind getQueriesForElement', async () => {
+    const {getByText} = getQueriesForElement(await getDocument(page))
+    const element = await getByText('Hello h1')
+    expect(await queries.getNodeText(element)).toEqual('Hello h1')
   })
 
   afterAll(async () => {