docs: add WrapperArray#exists docs (#1795)

Author: markrian

docs/api/wrapper-array/README.md

@@ -17,6 +17,7 @@ A `WrapperArray` is an object that contains an array of [`Wrappers`](../wrapper/
 !!!include(docs/api/wrapper-array/at.md)!!!
 !!!include(docs/api/wrapper-array/contains.md)!!!
 !!!include(docs/api/wrapper-array/destroy.md)!!!
+!!!include(docs/api/wrapper-array/exists.md)!!!
 !!!include(docs/api/wrapper-array/filter.md)!!!
 !!!include(docs/api/wrapper-array/is.md)!!!
 !!!include(docs/api/wrapper-array/isEmpty.md)!!!

docs/api/wrapper-array/exists.md

@@ -0,0 +1,19 @@
+## exists
+
+Assert `WrapperArray` exists.
+
+Returns false if called on a `WrapperArray` with no `Wrapper` objects, or if
+any of them do not exist.
+
+- **Returns:** `{boolean}`
+
+- **Example:**
+
+```js
+import { mount } from '@vue/test-utils'
+import Foo from './Foo.vue'
+
+const wrapper = mount(Foo)
+expect(wrapper.findAll('div').exists()).toBe(true)
+expect(wrapper.findAll('does-not-exist').exists()).toBe(false)
+```

docs/api/wrapper/exists.md

@@ -1,8 +1,8 @@
 ## exists
 
-Assert `Wrapper` or `WrapperArray` exists.
+Assert `Wrapper` exists.
 
-Returns false if called on an empty `Wrapper` or `WrapperArray`.
+Returns false if called on a `Wrapper` which does not exist.
 
 - **Returns:** `{boolean}`
 
@@ -15,6 +15,4 @@ import Foo from './Foo.vue'
 const wrapper = mount(Foo)
 expect(wrapper.exists()).toBe(true)
 expect(wrapper.find('does-not-exist').exists()).toBe(false)
-expect(wrapper.findAll('div').exists()).toBe(true)
-expect(wrapper.findAll('does-not-exist').exists()).toBe(false)
 ```

packages/test-utils/src/wrapper.js

@@ -208,7 +208,7 @@ export default class Wrapper implements BaseWrapper {
   }
 
   /**
-   * Utility to check wrapper exists. Returns true as Wrapper always exists
+   * Utility to check wrapper exists.
    */
   exists(): boolean {
     if (this.vm) {