Make lefthandObjectDiff private to verifyComponentAttributeEquivalence

Summary:
## Rationale
verifyComponentAttributeEquivalence is the legacy check for making sure that Static ViewConfigs match Native ViewConfigs. Eventually, we should just delete this module/check from the codebase.

## Changes
This diff migrates the RNHostComponentViewConfig differences screen to display the ViewConfig differences using the new StaticViewConfigValidator validation result vs the legacy validator's lefthandObjectDiff method.

## Benefits:
- Now, **all the diffing logic** on this route uses the new StaticViewConfigValidator.
- This takes us one step closer towards deleting verifyComponentAttributeEquivalence
- StaticViewConfigValidator [supports ignoring ViewConfig properties](https://fburl.com/code/2it5r7py). Now, the RNHostComponentViewConfig respects these ignores.

Changelog: [Internal]

Reviewed By: p-sun

Differential Revision: D34017602

fbshipit-source-id: 3ad909adcbb95b932a269dd55dd5445834a9cfd4

Libraries/NativeComponent/StaticViewConfigValidator.js

@@ -15,7 +15,7 @@ import getNativeComponentAttributes from '../ReactNative/getNativeComponentAttri
 import {createViewConfig} from './ViewConfig';
 import {isIgnored} from './ViewConfigIgnore';
 
-type Difference =
+export type Difference =
   | {
       type: 'missing',
       path: Array<string>,
@@ -33,7 +33,7 @@ type Difference =
       staticValue: mixed,
     };
 
-type ValidationResult = ValidResult | InvalidResult;
+export type ValidationResult = ValidResult | InvalidResult;
 type ValidResult = {
   type: 'valid',
 };
@@ -42,19 +42,15 @@ type InvalidResult = {
   differences: Array<Difference>,
 };
 
-type ViewConfigValidationResult = {
+// e.g. require('MyNativeComponent') where MyNativeComponent.js exports a HostComponent
+type JSModule = $FlowFixMe;
+
+export function validateStaticViewConfigs(nativeComponent: JSModule): {
   componentName: string,
   nativeViewConfig?: ?ViewConfig,
   staticViewConfig?: ?ViewConfig,
   validationResult?: ?ValidationResult,
-};
-
-// e.g. require('MyNativeComponent') where MyNativeComponent.js exports a HostComponent
-type JSModule = $FlowFixMe;
-
-export function validateStaticViewConfigs(
-  nativeComponent: JSModule,
-): ViewConfigValidationResult {
+} {
   const nativeViewConfig = getNativeComponentAttributes(
     nativeComponent.default || nativeComponent,
   );

Libraries/Utilities/verifyComponentAttributeEquivalence.js

@@ -62,7 +62,7 @@ export default function verifyComponentAttributeEquivalence(
 
 // Return the different key-value pairs of the right object, by iterating through the keys in the left object
 // Note it won't return a difference where a key is missing in the left but exists the right.
-export function lefthandObjectDiff(leftObj: Object, rightObj: Object): Object {
+function lefthandObjectDiff(leftObj: Object, rightObj: Object): Object {
   const differentKeys = {};
 
   function compare(leftItem: any, rightItem: any, key: string) {