[enzyme-adapter-utils] [refactor] remove unused code from createMountWrapper; add tests

Technically this could be considered a breaking change since it’s a
`class` and these are public methods on it.

*However*, since nobody should be depending on this package directly,
and since enzyme itself doesn’t appear to use it, I’m going to consider
it a patch. In the event that it is a breaking change for someone, I’ll
add back the methods, ideally as no-ops.

Author: ljharb

packages/enzyme-adapter-utils/src/createMountWrapper.jsx

@@ -48,7 +48,6 @@ export default function createMountWrapper(node, options = {}) {
     constructor(...args) {
       super(...args);
       const { props, wrappingComponentProps, context } = this.props;
-      this.rootFinderInstance = null;
       this.state = {
         mount: true,
         props,
@@ -68,28 +67,6 @@ export default function createMountWrapper(node, options = {}) {
       this.setState({ wrappingComponentProps: props }, callback);
     }
 
-    getInstance() {
-      const component = this._reactInternalInstance._renderedComponent;
-      const inst = component.getPublicInstance();
-      if (inst === null) {
-        return component._instance;
-      }
-      return inst;
-    }
-
-    getWrappedComponent() {
-      const component = this._reactInternalInstance._renderedComponent;
-      const inst = component.getPublicInstance();
-      if (inst === null) {
-        return component._instance;
-      }
-      return inst;
-    }
-
-    setChildContext(context) {
-      return new Promise((resolve) => this.setState({ context }, resolve));
-    }
-
     render() {
       const { Component } = this.props;
       const { mount, props, wrappingComponentProps } = this.state;

packages/enzyme-test-suite/test/adapter-utils-spec.jsx

@@ -1,6 +1,8 @@
 import React from 'react';
 import { expect } from 'chai';
 import sinon from 'sinon-sandbox';
+import PropTypes from 'prop-types';
+import { shallow } from 'enzyme';
 import {
   displayNameOfNode,
   ensureKeyOrUndefined,
@@ -14,6 +16,7 @@ import {
   getWrappingComponentMountRenderer,
   fakeDynamicImport,
   assertDomAvailable,
+  createMountWrapper,
 } from 'enzyme-adapter-utils';
 import wrap from 'mocha-wrap';
 
@@ -483,4 +486,28 @@ describe('enzyme-adapter-utils', () => {
       });
     });
   });
+
+  describe('createMountWrapper', () => {
+    class Foo extends React.Component {
+      render() { return <div>{this.context.foo}</div>; }
+    }
+    Foo.contextTypes = {
+      foo: PropTypes.string,
+    };
+
+    it('returns a component', () => {
+      const node = <Foo />;
+      const Wrapper = createMountWrapper(node);
+      expect(React.isValidElement(<Wrapper />)).to.equal(true);
+    });
+
+    it('returns the wrapped component’s instance', () => {
+      const node = <Foo />;
+      const Wrapper = createMountWrapper(node);
+      const wrapper = shallow(<Wrapper />);
+      expect(wrapper.instance()).to.be.instanceOf(Wrapper);
+    });
+
+    it('uses the passed `wrappingComponent`', () => {});
+  });
 });