Improvements based on feedback.

* Documented jQuery vs DOM nodes.
* Use Cypress.cy global.
* Renamed function and parameter.
* Moved utils file.

Author: npeterkamps

README.md

@@ -82,6 +82,8 @@ cy.get('form').then((subject) => {
 })
 ```
 
+`cypress-testing-library` supports both jQuery elements and DOM nodes. This is necessary because Cypress uses jQuery elements, while `dom-testing-library` expects DOM nodes. When you pass a jQuery element as `container`, it will get the first DOM node from the collection and use that as the `container` parameter for the `dom-testing-library` functions.
+
 ## Other Solutions
 
 I'm not aware of any, if you are please [make a pull request][prs] and add it

src/index.js

@@ -1,5 +1,5 @@
 import {queries, waitForElement} from 'dom-testing-library'
-import {getContainer} from './support/utils'
+import {getContainer} from './utils'
 
 const defaults = {
   timeout: 3000,
@@ -16,7 +16,7 @@ const commands = Object.keys(queries).map(queryName => {
 
       const queryImpl = queries[queryName]
       const baseCommandImpl = doc => {
-        const container = getContainer(cy, waitOptions.container || doc);
+        const container = getContainer(waitOptions.container || doc);
         return waitForElement(() => queryImpl(container, ...args), Object.assign({}, waitOptions, {
           container,
         }))

src/support/utils.js

@@ -0,0 +1,21 @@
+function getFirstElement(jqueryOrElement) {
+  if (Cypress.dom.isJquery(jqueryOrElement)) {
+    return jqueryOrElement.get(0)
+  }
+  return jqueryOrElement
+}
+
+function getContainer(container) {
+  const withinContainer = Cypress.cy.state('withinSubject')
+  if (withinContainer) {
+    return getFirstElement(withinContainer)
+  }
+  return getFirstElement(container)
+}
+
+export {
+  getFirstElement,
+  getContainer,
+}
+
+/* globals Cypress */