From 0359fd2e5ca31ebe9b71595b985b4588b4382b0f Mon Sep 17 00:00:00 2001
From: Rafael de Oleza <rafeca@fb.com>
Date: Tue, 2 Aug 2016 16:40:47 -0700
Subject: [PATCH] [RFC] Proposal for ReactTestRenderer selector API

---
 src/renderers/testing/ReactTestMount.js       |  12 ++
 src/renderers/testing/ReactTestRenderer.js    |  69 ++++++++++
 .../__tests__/ReactTestRenderer-test.js       | 130 ++++++++++++++++++
 3 files changed, 211 insertions(+)

diff --git a/src/renderers/testing/ReactTestMount.js b/src/renderers/testing/ReactTestMount.js
index a3f2e61aff7..89f964b7b2c 100644
--- a/src/renderers/testing/ReactTestMount.js
+++ b/src/renderers/testing/ReactTestMount.js
@@ -130,6 +130,18 @@ ReactTestInstance.prototype.toJSON = function() {
   var inst = getHostComponentFromComposite(this._component);
   return inst.toJSON();
 };
+ReactTestInstance.prototype.find = function(selector) {
+  var inst = getHostComponentFromComposite(this._component);
+  return inst.find(selector, false);
+};
+ReactTestInstance.prototype.findAll = function(selector) {
+  var inst = getHostComponentFromComposite(this._component);
+  return inst.findAll(selector);
+};
+ReactTestInstance.prototype.findByProps = function(props) {
+  var inst = getHostComponentFromComposite(this._component);
+  return inst.findByProps(props);
+};
 
 /**
  * As soon as `ReactMount` is refactored to not rely on the DOM, we can share
diff --git a/src/renderers/testing/ReactTestRenderer.js b/src/renderers/testing/ReactTestRenderer.js
index b2d18464629..f82839d2c09 100644
--- a/src/renderers/testing/ReactTestRenderer.js
+++ b/src/renderers/testing/ReactTestRenderer.js
@@ -90,6 +90,66 @@ ReactTestComponent.prototype.toJSON = function() {
   });
   return object;
 };
+ReactTestComponent.prototype.getType = function() {
+  return this._currentElement.type;
+};
+ReactTestComponent.prototype.getProps = function() {
+  return this._currentElement.props;
+};
+ReactTestComponent.prototype.getChildren = function() {
+  return Object.keys(this._renderedChildren || {}).map(function(key) {
+    return this._renderedChildren[key];
+  }, this);
+};
+ReactTestComponent.prototype.find = function(selector) {
+  if (this.getType() === selector) {
+    return this;
+  }
+  var children = this.getChildren();
+
+  for (var key in children) {
+    var inst = children[key];
+    let result = inst.find(selector);
+    if (result) {
+      return result;
+    }
+  }
+  return null;
+};
+ReactTestComponent.prototype.findAll = function(selector, props) {
+  var output = [];
+
+  if (this.getType() === selector) {
+    output.push(this);
+  }
+
+  return this.getChildren().reduce(function(current, inst) {
+    return current.concat(inst.findAll(selector));
+  }, output);
+};
+ReactTestComponent.prototype.findByProps = function(props) {
+  var propsEqual = true;
+  for (var key in props) {
+    if (this.getProps()[key] !== props[key]) {
+      propsEqual = false;
+      break;
+    }
+  }
+  if (propsEqual) {
+    return this;
+  }
+
+  var children = this.getChildren();
+  for (key in children) {
+    var inst = children[key];
+    let result = inst.findByProps(props);
+    if (result) {
+      return result;
+    }
+  }
+  return null;
+};
+
 Object.assign(ReactTestComponent.prototype, ReactMultiChild.Mixin);
 
 // =============================================================================
@@ -106,6 +166,15 @@ ReactTestTextComponent.prototype.unmountComponent = function() {};
 ReactTestTextComponent.prototype.toJSON = function() {
   return this._currentElement;
 };
+ReactTestTextComponent.prototype.find = function() {
+  return null;
+};
+ReactTestTextComponent.prototype.findAll = function() {
+  return [];
+};
+ReactTestTextComponent.prototype.findByProps = function() {
+  return null;
+};
 
 // =============================================================================
 
diff --git a/src/renderers/testing/__tests__/ReactTestRenderer-test.js b/src/renderers/testing/__tests__/ReactTestRenderer-test.js
index a20d442686d..4e700f028b0 100644
--- a/src/renderers/testing/__tests__/ReactTestRenderer-test.js
+++ b/src/renderers/testing/__tests__/ReactTestRenderer-test.js
@@ -198,4 +198,134 @@ describe('ReactTestRenderer', function() {
     expect(log).toEqual([null]);
   });
 
+  describe('selectors API', function() {
+    it('finds one element by name', function() {
+      class Component extends React.Component {
+        render() {
+          return (
+            <div>
+              <div>one element</div>
+              <myelement id={1} />
+              <span>
+                <div>
+                  <myelement id={2}/>
+                </div>
+              </span>
+            </div>
+          );
+        }
+      }
+
+      var renderer = ReactTestRenderer.create(<Component />);
+
+      var myelement = renderer.find('myelement');
+      expect(myelement.getProps().id).toEqual(1);
+    });
+
+    it('concatenates finders', function() {
+      class Component extends React.Component {
+        render() {
+          return (
+            <div>
+              <div>one element</div>
+              <myelement id={1} />
+              <span>
+                <div>
+                  <myelement id={2}/>
+                </div>
+              </span>
+            </div>
+          );
+        }
+      }
+
+      var renderer = ReactTestRenderer.create(<Component />);
+
+      var myelement = renderer.find('span').find('myelement');
+      expect(myelement.getProps().id).toEqual(2);
+    });
+
+    it('finds all elements by name', function() {
+      class Component extends React.Component {
+        render() {
+          return (
+            <div>
+              <div>one element</div>
+              <myelement id={1} />
+              <span>
+                <div>
+                  <myelement id={2}/>
+                </div>
+              </span>
+            </div>
+          );
+        }
+      }
+
+      var renderer = ReactTestRenderer.create(<Component />);
+
+      var myelements = renderer.findAll('myelement');
+      expect(myelements.length).toBe(2);
+      expect(myelements[0].getProps().id).toBe(1);
+      expect(myelements[1].getProps().id).toBe(2);
+    });
+
+    it('finds an element by props', function() {
+      class Component extends React.Component {
+        render() {
+          return (
+            <div>
+              <div>one element</div>
+              <myelement className={'found'} id={1} />
+              <span>
+                <div>
+                  <myelement className={'found'} id={2} another={true} />
+                </div>
+              </span>
+            </div>
+          );
+        }
+      }
+
+      var renderer = ReactTestRenderer.create(<Component />);
+
+      var myelement = renderer.findByProps({
+        className: 'found',
+        id: 2,
+      });
+      expect(myelement.getProps()).toEqual({
+        className: 'found',
+        id: 2,
+        another: true,
+      });
+    });
+
+    it('can use finders to trigger events', function() {
+      class Component extends React.Component {
+        constructor() {
+          super();
+          this.state = { clicked: 0 };
+        }
+
+        render() {
+          return (
+            <div>
+              <span>{this.state.clicked}</span>
+              <myelement onClick={this._onClick}/>
+            </div>
+          );
+        }
+        _onClick = () => {
+          this.setState({clicked: 1});
+        }
+      }
+
+      var renderer = ReactTestRenderer.create(<Component />);
+
+      expect(renderer.find('span').getChildren()[0].toJSON()).toEqual(0);
+
+      renderer.find('myelement').getProps().onClick();
+      expect(renderer.find('span').getChildren()[0].toJSON()).toEqual(1);
+    });
+  });
 });