adds comment about where ReactTestInstance has come from

packages/enzyme-adapter-react-renderer/package.json

@@ -36,10 +36,17 @@
   "dependencies": {
     "cheerio": "^1.0.0-rc.2",
     "enzyme-adapter-utils": "^1.3.0",
+    "has": "^1.0.1",
     "invariant": "^2.2.4",
+    "is-subset": "^0.1.1",
+    "lodash": "^4.17.4",
+    "object.entries": "^1.0.4",
+    "object.values": "^1.0.4",
+    "object-is": "^1.0.1",
     "react-is": "^16.3.2",
     "react-reconciler": "^0.7.0",
-    "react-test-renderer": "^16.3.2"
+    "react-test-renderer": "^16.3.2",
+    "rst-selector-parser": "^2.2.3"
   },
   "peerDependencies": {
     "enzyme": "^3.0.0",

packages/enzyme-adapter-react-renderer/src/ReactMountWrapper.js

@@ -5,6 +5,8 @@ import ReactDOMServer from 'react-dom/server';
 import ReactTestRendererAdapter from './ReactTestRendererAdapter';
 import ReactTestInstance from './ReactTestInstance';
 
+import { reduceTreesBySelector } from './selectors';
+
 const noop = () => {};
 
 const flatMap = (collection, fn) =>
@@ -70,14 +72,46 @@ class ReactMountWrapper {
     return _context;
   }
 
+  /**
+   * Finds every node in the render tree of the current wrapper that matches the provided selector.
+   *
+   * @param {String|Function} selector
+   * @returns {ReactWrapper}
+   */
   find(selector) {
     return new ReactMountWrapper(
-      flatMap(this.instances, instance => instance.findAllByType(selector)),
+      reduceTreesBySelector(selector, this.instances),
       this.rootWrapper,
       this.rootNode,
     );
   }
 
+  /**
+   * Finds all nodes in the current wrapper nodes' render trees that match the provided predicate
+   * function.
+   *
+   * @param {Function} predicate
+   * @returns {ReactWrapper}
+   */
+  findWhere(predicate) {
+    return new ReactMountWrapper(
+      flatMap(this.instances, instance =>
+        instance.findAll(testInstance =>
+          predicate(new ReactMountWrapper([testInstance], this.rootWrapper, this.rootNode)))),
+      this.rootWrapper,
+      this.rootNode,
+    );
+  }
+
+  /**
+   * Returns a wrapper around the first node of the current wrapper.
+   *
+   * @returns {ReactWrapper}
+   */
+  first() {
+    return this.at(0);
+  }
+
   /**
    * Returns the HTML of the node.
    *
@@ -119,6 +153,15 @@ class ReactMountWrapper {
     return first && first.parent.instance !== this.rootWrapper;
   }
 
+  /**
+   * Returns a wrapper around the last node of the current wrapper.
+   *
+   * @returns {ReactWrapper}
+   */
+  last() {
+    return this.at(this.length - 1);
+  }
+
   /**
    * Returns the name of the root node of this wrapper.
    *
@@ -133,6 +176,16 @@ class ReactMountWrapper {
     });
   }
 
+  /**
+   * Returns the value of  prop with the given name of the root node.
+   *
+   * @param {String} propName
+   * @returns {*}
+   */
+  prop(propName) {
+    return this.props()[propName];
+  }
+
   /**
    * Returns the props hash for the root node of the wrapper.
    *

packages/enzyme-adapter-react-renderer/src/ReactTestInstance.js

@@ -1,4 +1,7 @@
-import {findCurrentFiberUsingSlowPath} from 'react-reconciler/reflection';
+// COPIED FROM https://github.com/facebook/react/blob/master/packages/react-test-renderer/src/ReactTestRenderer.js
+// Ideally ReactTestInstance would be exported from the react-test-renderer package
+
+import { findCurrentFiberUsingSlowPath } from 'react-reconciler/reflection';
 import invariant from 'invariant';
 
 export const IndeterminateComponent = 0; // Before we know whether it is functional or class
@@ -17,12 +20,7 @@ export const ContextConsumer = 12;
 export const ContextProvider = 13;
 export const ForwardRef = 14;
 
-const validWrapperTypes = new Set([
-  FunctionalComponent,
-  ClassComponent,
-  HostComponent,
-  ForwardRef,
-]);
+const validWrapperTypes = new Set([FunctionalComponent, ClassComponent, HostComponent, ForwardRef]);
 
 function getPublicInstance(inst) {
   switch (inst.tag) {
@@ -51,27 +49,18 @@ function wrapFiber(fiber) {
   return wrapper;
 }
 
-function expectOne(
-  all,
-  message,
-) {
+function expectOne(all, message) {
   if (all.length === 1) {
     return all[0];
   }
 
   const prefix =
-    all.length === 0
-      ? 'No instances found '
-      : `Expected 1 but found ${all.length} instances `;
+    all.length === 0 ? 'No instances found ' : `Expected 1 but found ${all.length} instances `;
 
   throw new Error(prefix + message);
 }
 
-function findAll(
-  root,
-  predicate,
-  options,
-) {
+function findAll(root, predicate, options) {
   const deep = options ? options.deep : true;
   const results = [];
 
@@ -126,9 +115,8 @@ class ReactTestInstance {
   get instance() {
     if (this._fiber.tag === HostComponent) {
       return getPublicInstance(this._fiber.stateNode);
-    } else {
-      return this._fiber.stateNode;
     }
+    return this._fiber.stateNode;
   }
 
   get type() {
@@ -141,9 +129,7 @@ class ReactTestInstance {
 
   get parent() {
     const parent = this._fiber.return;
-    return parent === null || parent.tag === HostRoot
-      ? null
-      : wrapFiber(parent);
+    return parent === null || parent.tag === HostRoot ? null : wrapFiber(parent);
   }
 
   get children() {
@@ -165,7 +151,7 @@ class ReactTestInstance {
           children.push(wrapFiber(node));
           break;
         case HostText:
-          children.push('' + node.memoizedProps);
+          children.push(`${node.memoizedProps}`);
           break;
         case Fragment:
         case ContextProvider:
@@ -176,8 +162,7 @@ class ReactTestInstance {
         default:
           invariant(
             false,
-            'Unsupported component type %s in test renderer. ' +
-              'This is probably a bug in React.',
+            'Unsupported component type %s in test renderer. ' + 'This is probably a bug in React.',
             node.tag,
           );
       }
@@ -190,59 +175,46 @@ class ReactTestInstance {
         if (node.return === startingNode) {
           break outer;
         }
-        node = (node.return);
+        node = node.return;
       }
-      (node.sibling).return = node.return;
-      node = (node.sibling);
+      node.sibling.return = node.return;
+      node = node.sibling;
     }
     return children;
   }
 
   // Custom search functions
   find(predicate) {
     return expectOne(
-      this.findAll(predicate, {deep: false}),
+      this.findAll(predicate, { deep: false }),
       `matching custom predicate: ${predicate.toString()}`,
     );
   }
 
   findByType(type) {
     return expectOne(
-      this.findAllByType(type, {deep: false}),
+      this.findAllByType(type, { deep: false }),
       `with node type: "${type.displayName || type.name}"`,
     );
   }
 
   findByProps(props) {
     return expectOne(
-      this.findAllByProps(props, {deep: false}),
+      this.findAllByProps(props, { deep: false }),
       `with props: ${JSON.stringify(props)}`,
     );
   }
 
-  findAll(
-    predicate,
-    options = null,
-  ) {
+  findAll(predicate, options = null) {
     return findAll(this, predicate, options);
   }
 
-  findAllByType(
-    type,
-    options = null,
-  ) {
+  findAllByType(type, options = null) {
     return findAll(this, node => node.type === type, options);
   }
 
-  findAllByProps(
-    props,
-    options = null,
-  ) {
-    return findAll(
-      this,
-      node => node.props && propsMatch(node.props, props),
-      options,
-    );
+  findAllByProps(props, options = null) {
+    return findAll(this, node => node.props && propsMatch(node.props, props), options);
   }
 }