From d959599acf7784b8b257cf3a63992af9050faf00 Mon Sep 17 00:00:00 2001
From: jim <none@no-reply.com>
Date: Thu, 11 Feb 2016 09:58:19 -0800
Subject: [PATCH] Initial pass at the easy case of updates (updates that start
 at the root).

---
 .../__tests__/ReactErrorBoundaries-test.js    | 205 +++++++++++++++++-
 .../reconciler/ReactCompositeComponent.js     |  55 ++++-
 2 files changed, 253 insertions(+), 7 deletions(-)

diff --git a/src/core/__tests__/ReactErrorBoundaries-test.js b/src/core/__tests__/ReactErrorBoundaries-test.js
index 0ba37323d5522..6eb4486230674 100644
--- a/src/core/__tests__/ReactErrorBoundaries-test.js
+++ b/src/core/__tests__/ReactErrorBoundaries-test.js
@@ -55,7 +55,7 @@ describe('ReactErrorBoundaries', function() {
     expect(EventPluginHub.putListener).not.toBeCalled();
   });
 
-  it('will catch exceptions in componentWillUnmount', function() {
+  it('will catch exceptions in componentWillUnmount initial render', function() {
     class ErrorBoundary extends React.Component {
       constructor() {
         super();
@@ -236,4 +236,207 @@ describe('ReactErrorBoundaries', function() {
       'Box componentWillUnmount',
     ]);
   });
+
+  it('catches errors on update', function() {
+    var log = [];
+
+    class Box extends React.Component {
+      constructor(props) {
+        super(props);
+        this.state = {errorMessage: null};
+      }
+      render() {
+        if (this.state.errorMessage != null) {
+          log.push('Box renderError');
+          return <div>Error: {this.state.errorMessage}</div>;
+        }
+        log.push('Box render');
+        var ref = function(x) {
+          log.push('Inquisitive ref ' + x);
+        };
+        return (
+          <div>
+            <Inquisitive ref={ref} />
+            {this.props.angry ? <Angry /> : <div />}
+          </div>
+        );
+      }
+      unstable_handleError(e) {
+        log.push('error handled');
+        this.setState({errorMessage: e.message});
+      }
+      componentDidMount() {
+        log.push('Box componentDidMount');
+      }
+      componentWillUnmount() {
+        log.push('Box componentWillUnmount');
+      }
+    }
+
+    class Inquisitive extends React.Component {
+      render() {
+        log.push('Inquisitive render');
+        return <div>What is love?</div>;
+      }
+      componentDidMount() {
+        log.push('Inquisitive componentDidMount');
+      }
+      componentWillUnmount() {
+        log.push('Inquisitive componentWillUnmount');
+      }
+    }
+
+    class Angry extends React.Component {
+      render() {
+        log.push('Angry render');
+        throw new Error('Please, do not render me.');
+      }
+      componentDidMount() {
+        log.push('Angry componentDidMount');
+      }
+      componentWillUnmount() {
+        log.push('Angry componentWillUnmount');
+      }
+    }
+
+    var container = document.createElement('div');
+    ReactDOM.render(<Box angry={false} />, container);
+    ReactDOM.render(<Box angry={true} />, container);
+    expect(container.textContent).toBe('Error: Please, do not render me.');
+    expect(log).toEqual([
+      'Box render',
+      'Inquisitive render',
+      'Inquisitive componentDidMount',
+      'Inquisitive ref [object Object]',
+      'Box componentDidMount',
+      'Box render',
+      'Inquisitive ref null',
+      'Inquisitive render',
+      'Angry render',
+      'error handled',
+      'Inquisitive ref null',
+      'Inquisitive componentWillUnmount',
+      'Box renderError',
+    ]);
+  });
+
+  it('catches componentWillUnmount errors on update', function() {
+    var log = [];
+
+    class ErrorBoundary extends React.Component {
+      constructor(props) {
+        super(props);
+        this.state = {errorMessage: null};
+      }
+      render() {
+        if (this.state.errorMessage != null) {
+          log.push('Box renderError');
+          return <div>Error: I am now a sad component :(</div>;
+        }
+        log.push('Box render');
+
+        return (
+          <div>
+            <BrokenUnmount />
+            <BrokenUnmount />
+            {this.props.angry ? null : <BrokenUnmount />}
+          </div>
+        );
+      }
+      unstable_handleError(e) {
+        log.push('error handled');
+        this.setState({errorMessage: e.message});
+      }
+      componentDidMount() {
+        log.push('Box componentDidMount');
+      }
+      componentWillUnmount() {
+        log.push('Box componentWillUnmount');
+      }
+    }
+
+    class BrokenUnmount extends React.Component {
+      render() {
+        return <div />;
+      }
+      componentWillUnmount() {
+        log.push('BrokenUnmount is attempting to unmount');
+        throw new Error('Always broken.');
+      }
+    }
+
+    var container = document.createElement('div');
+    ReactDOM.render(<ErrorBoundary angry={false} />, container);
+    ReactDOM.render(<ErrorBoundary angry={true} />, container);
+    expect(container.textContent).toBe('Error: I am now a sad component :(');
+    expect(log).toEqual([
+      'Box render',
+      'Box componentDidMount',
+      'Box render',
+      'BrokenUnmount is attempting to unmount',
+      'error handled',
+      'BrokenUnmount is attempting to unmount',
+      'BrokenUnmount is attempting to unmount',
+      'BrokenUnmount is attempting to unmount',
+      'Box renderError',
+    ]);
+    ReactDOM.unmountComponentAtNode(container);
+    expect(log).toEqual([
+      'Box render',
+      'Box componentDidMount',
+      'Box render',
+      'BrokenUnmount is attempting to unmount',
+      'error handled',
+      'BrokenUnmount is attempting to unmount',
+      'BrokenUnmount is attempting to unmount',
+      'BrokenUnmount is attempting to unmount',
+      'Box renderError',
+      'Box componentWillUnmount',
+    ]);
+  });
+
+  it('catches componentWillUnmount errors nested children', function() {
+    class ErrorBoundary extends React.Component {
+      constructor(props) {
+        super(props);
+        this.state = {errorMessage: null};
+      }
+      render() {
+        if (this.state.errorMessage != null) {
+          return <div>Error: I am now a sad component :(</div>;
+        }
+
+        return (
+          <div>
+            <InnocentParent />
+            {this.props.angry ? null : <InnocentParent />}
+          </div>
+        );
+      }
+      unstable_handleError(e) {
+        this.setState({errorMessage: e.message});
+      }
+    }
+
+    class InnocentParent extends React.Component {
+      render() {
+        return <BrokenUnmount />;
+      }
+    }
+
+    class BrokenUnmount extends React.Component {
+      render() {
+        return <div />;
+      }
+      componentWillUnmount() {
+        throw new Error('Always broken.');
+      }
+    }
+
+    var container = document.createElement('div');
+    ReactDOM.render(<ErrorBoundary angry={false} />, container);
+    ReactDOM.render(<ErrorBoundary angry={true} />, container);
+    expect(container.textContent).toBe('Error: I am now a sad component :(');
+    ReactDOM.unmountComponentAtNode(container);
+  });
 });
diff --git a/src/renderers/shared/reconciler/ReactCompositeComponent.js b/src/renderers/shared/reconciler/ReactCompositeComponent.js
index 65b28c6c773cf..e54eedd75dc96 100644
--- a/src/renderers/shared/reconciler/ReactCompositeComponent.js
+++ b/src/renderers/shared/reconciler/ReactCompositeComponent.js
@@ -342,7 +342,6 @@ var ReactCompositeComponentMixin = {
         this._instance.state = this._processPendingState(this._instance.props, this._instance.context);
       }
       checkpoint = transaction.checkpoint();
-
       this._renderedComponent.unmountComponent(true);
       transaction.rollback(checkpoint);
 
@@ -406,7 +405,7 @@ var ReactCompositeComponentMixin = {
         var name = this.getName() + '.componentWillUnmount()';
         ReactErrorUtils.invokeGuardedCallback(name, inst.componentWillUnmount.bind(inst));
       } else {
-        inst.componentWillUnmount();
+        inst.componentWillUnmount(safely);
       }
     }
 
@@ -808,7 +807,11 @@ var ReactCompositeComponentMixin = {
     inst.state = nextState;
     inst.context = nextContext;
 
-    this._updateRenderedComponent(transaction, unmaskedContext);
+    if (inst.unstable_handleError) {
+      this._updateRenderedComponentWithErrorHandling(transaction, unmaskedContext);
+    } else {
+      this._updateRenderedComponent(transaction, unmaskedContext);
+    }
 
     if (hasComponentDidUpdate) {
       transaction.getReactMountReady().enqueue(
@@ -818,6 +821,35 @@ var ReactCompositeComponentMixin = {
     }
   },
 
+  /**
+   * Call the component's `render` method and update the DOM accordingly.
+   *
+   * @param {ReactReconcileTransaction} transaction
+   * @internal
+   */
+  _updateRenderedComponentWithErrorHandling: function(transaction, context) {
+    var checkpoint = transaction.checkpoint();
+    try {
+      this._updateRenderedComponent(transaction, context);
+    } catch (e) {
+      // Roll back to checkpoint, handle error (which may add items to the transaction),
+      // and take a new checkpoint
+      transaction.rollback(checkpoint);
+      this._instance.unstable_handleError(e);
+      if (this._pendingStateQueue) {
+        this._instance.state = this._processPendingState(this._instance.props, this._instance.context);
+      }
+      checkpoint = transaction.checkpoint();
+
+      // Gracefully update to a clean state
+      this._updateRenderedComponentWithNextElement(transaction, context, null, true);
+
+      // Try again - we've informed the component about the error, so they can render an error message this time.
+      // If this throws again, the error will bubble up (and can be caught by a higher error boundary).
+      this._updateRenderedComponent(transaction, context);
+    }
+  },
+
   /**
    * Call the component's `render` method and update the DOM accordingly.
    *
@@ -825,19 +857,30 @@ var ReactCompositeComponentMixin = {
    * @internal
    */
   _updateRenderedComponent: function(transaction, context) {
+    var nextRenderedElement = this._renderValidatedComponent();
+    this._updateRenderedComponentWithNextElement(transaction, context, nextRenderedElement, false);
+  },
+
+  /**
+   * Call the component's `render` method and update the DOM accordingly.
+   *
+   * @param {ReactReconcileTransaction} transaction
+   * @internal
+   */
+  _updateRenderedComponentWithNextElement: function(transaction, context, nextRenderedElement, safely) {
     var prevComponentInstance = this._renderedComponent;
     var prevRenderedElement = prevComponentInstance._currentElement;
-    var nextRenderedElement = this._renderValidatedComponent();
     if (shouldUpdateReactComponent(prevRenderedElement, nextRenderedElement)) {
       ReactReconciler.receiveComponent(
         prevComponentInstance,
         nextRenderedElement,
         transaction,
-        this._processChildContext(context)
+        this._processChildContext(context),
+        safely
       );
     } else {
       var oldNativeNode = ReactReconciler.getNativeNode(prevComponentInstance);
-      ReactReconciler.unmountComponent(prevComponentInstance, false);
+      ReactReconciler.unmountComponent(prevComponentInstance, safely);
 
       this._renderedNodeType = ReactNodeTypes.getType(nextRenderedElement);
       this._renderedComponent = this._instantiateReactComponent(