Refactor findHostInstance

The reconciler shouldn't expose the Fiber data structure. We should pass
the component instance to the reconciler, since the reconciler is the
thing that is supposed to be instancemap aware.

packages/react-dom/src/client/ReactDOM.js

@@ -1147,20 +1147,7 @@ const ReactDOM: Object = {
       return (componentOrElement: any);
     }
 
-    const inst = ReactInstanceMap.get(componentOrElement);
-    if (inst) {
-      return DOMRenderer.findHostInstance(inst);
-    }
-
-    if (typeof componentOrElement.render === 'function') {
-      invariant(false, 'Unable to find node on an unmounted component.');
-    } else {
-      invariant(
-        false,
-        'Element appears to be neither ReactComponent nor DOMNode. Keys: %s',
-        Object.keys(componentOrElement),
-      );
-    }
+    return DOMRenderer.findHostInstance(componentOrElement);
   },
 
   hydrate(element: React$Node, container: DOMContainer, callback: ?Function) {

packages/react-native-renderer/src/NativeMethodsMixin.js

@@ -26,7 +26,6 @@ import {
   throwOnStylesProp,
   warnForStyleProps,
 } from './NativeMethodsMixinUtils';
-import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 
 export default function(
   findNodeHandle: any => ?number,
@@ -129,17 +128,12 @@ export default function(
       // We want the instance/wrapper (not the native tag).
       let maybeInstance;
 
-      const fiber = ReactInstanceMap.get(this);
-      if (!fiber) {
-        return;
-      }
-
       // Fiber errors if findNodeHandle is called for an umounted component.
       // Tests using ReactTestRenderer will trigger this case indirectly.
       // Mimicking stack behavior, we should silently ignore this case.
       // TODO Fix ReactTestRenderer so we can remove this try/catch.
       try {
-        maybeInstance = findHostInstance(fiber);
+        maybeInstance = findHostInstance(this);
       } catch (error) {}
 
       // If there is no host component beneath this we should fail silently.

packages/react-native-renderer/src/ReactFabric.js

@@ -26,10 +26,7 @@ import {getInspectorDataForViewTag} from './ReactNativeFiberInspector';
 import createReactNativeComponentClass from './createReactNativeComponentClass';
 
 import {ReactCurrentOwner} from 'shared/ReactGlobalSharedState';
-import type {Fiber} from 'react-reconciler/src/ReactFiber';
-import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 import getComponentName from 'shared/getComponentName';
-import invariant from 'fbjs/lib/invariant';
 import warning from 'fbjs/lib/warning';
 
 const findHostInstance = ReactFabricRenderer.findHostInstance;
@@ -64,11 +61,7 @@ function findNodeHandle(componentOrHandle: any): ?number {
   if (componentOrHandle.canonical && componentOrHandle.canonical._nativeTag) {
     return componentOrHandle.canonical._nativeTag;
   }
-  const internalInstance: Fiber = ReactInstanceMap.get(componentOrHandle);
-  if (!internalInstance) {
-    return null;
-  }
-  const hostInstance = findHostInstance(internalInstance);
+  const hostInstance = findHostInstance(componentOrHandle);
   if (hostInstance == null) {
     return hostInstance;
   }

packages/react-native-renderer/src/ReactNativeComponent.js

@@ -23,7 +23,6 @@ import UIManager from 'UIManager';
 
 import * as ReactNativeAttributePayload from './ReactNativeAttributePayload';
 import {mountSafeCallback} from './NativeMethodsMixinUtils';
-import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 
 export default function(
   findNodeHandle: any => ?number,
@@ -140,17 +139,12 @@ export default function(
       // We want the instance/wrapper (not the native tag).
       let maybeInstance;
 
-      const fiber = ReactInstanceMap.get(this);
-      if (!fiber) {
-        return;
-      }
-
       // Fiber errors if findNodeHandle is called for an umounted component.
       // Tests using ReactTestRenderer will trigger this case indirectly.
       // Mimicking stack behavior, we should silently ignore this case.
       // TODO Fix ReactTestRenderer so we can remove this try/catch.
       try {
-        maybeInstance = findHostInstance(fiber);
+        maybeInstance = findHostInstance(this);
       } catch (error) {}
 
       // If there is no host component beneath this we should fail silently.

packages/react-native-renderer/src/ReactNativeRenderer.js

@@ -30,10 +30,7 @@ import {getInspectorDataForViewTag} from './ReactNativeFiberInspector';
 import createReactNativeComponentClass from './createReactNativeComponentClass';
 
 import {ReactCurrentOwner} from 'shared/ReactGlobalSharedState';
-import type {Fiber} from 'react-reconciler/src/ReactFiber';
-import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 import getComponentName from 'shared/getComponentName';
-import invariant from 'fbjs/lib/invariant';
 import warning from 'fbjs/lib/warning';
 
 const findHostInstance = ReactNativeFiberRenderer.findHostInstance;
@@ -68,11 +65,7 @@ function findNodeHandle(componentOrHandle: any): ?number {
   if (componentOrHandle.canonical && componentOrHandle.canonical._nativeTag) {
     return componentOrHandle.canonical._nativeTag;
   }
-  const internalInstance: Fiber = ReactInstanceMap.get(componentOrHandle);
-  if (!internalInstance) {
-    return null;
-  }
-  const hostInstance = findHostInstance(internalInstance);
+  const hostInstance = findHostInstance(componentOrHandle);
   if (hostInstance == null) {
     return hostInstance;
   }

packages/react-noop-renderer/src/ReactNoop.js

@@ -19,7 +19,6 @@ import type {UpdateQueue} from 'react-reconciler/src/ReactFiberUpdateQueue';
 import type {ReactNodeList} from 'shared/ReactTypes';
 import ReactFiberReconciler from 'react-reconciler';
 import {enablePersistentReconciler} from 'shared/ReactFeatureFlags';
-import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 import * as ReactPortal from 'shared/ReactPortal';
 import emptyObject from 'fbjs/lib/emptyObject';
 import expect from 'expect';
@@ -401,8 +400,7 @@ const ReactNoop = {
     if (typeof component.id === 'number') {
       return component;
     }
-    const inst = ReactInstanceMap.get(component);
-    return inst ? NoopRenderer.findHostInstance(inst) : null;
+    return NoopRenderer.findHostInstance(component);
   },
 
   flushDeferredPri(timeout: number = Infinity): Array<mixed> {

packages/react-reconciler/src/ReactFiberReconciler.js

@@ -20,6 +20,7 @@ import * as ReactInstanceMap from 'shared/ReactInstanceMap';
 import {HostComponent} from 'shared/ReactTypeOfWork';
 import emptyObject from 'fbjs/lib/emptyObject';
 import getComponentName from 'shared/getComponentName';
+import invariant from 'fbjs/lib/invariant';
 import warning from 'fbjs/lib/warning';
 
 import {createFiberRoot} from './ReactFiberRoot';
@@ -264,7 +265,7 @@ export type Reconciler<C, I, TI> = {
   ): React$Component<any, any> | TI | I | null,
 
   // Use for findDOMNode/findHostNode. Legacy API.
-  findHostInstance(component: Fiber): I | TI | null,
+  findHostInstance(component: Object): I | TI | null,
 
   // Used internally for filtering out portals. Legacy API.
   findHostInstanceWithNoPortals(component: Fiber): I | TI | null,
@@ -402,7 +403,19 @@ export default function<T, P, I, TI, HI, PI, C, CC, CX, PL>(
     );
   }
 
-  function findHostInstance(fiber: Fiber): PI | null {
+  function findHostInstance(component: Object): PI | null {
+    const fiber = ReactInstanceMap.get(component);
+    if (fiber === undefined) {
+      if (typeof component.render === 'function') {
+        invariant(false, 'Unable to find node on an unmounted component.');
+      } else {
+        invariant(
+          false,
+          'Argument appears to not be a ReactComponent. Keys: %s',
+          Object.keys(component),
+        );
+      }
+    }
     const hostFiber = findCurrentHostFiber(fiber);
     if (hostFiber === null) {
       return null;