RN: Cleanup ReactFiberErrorDialog

Summary:
Minor cleanup of `ReactFiberErrorDialog` with no behavior changes.

Changelog:
[Internal]

Reviewed By: GijsWeterings

Differential Revision: D28423265

fbshipit-source-id: 796777ca2c26d6d7cfae956299786151c74e937f

Author: yungsters

Libraries/Core/ReactFiberErrorDialog.js

@@ -8,45 +8,49 @@
  * @flow strict-local
  */
 
+import {handleException, SyntheticError} from './ExceptionsManager';
+
+import type {ExtendedError} from './Devtools/parseErrorStack';
+
 export type CapturedError = {
   +componentStack: string,
   +error: mixed,
   +errorBoundary: ?{...},
   ...
 };
 
-import type {ExtendedError} from './Devtools/parseErrorStack';
-
-import {handleException, SyntheticError} from './ExceptionsManager';
+const ReactFiberErrorDialog = {
+  /**
+   * Intercept lifecycle errors and ensure they are shown with the correct stack
+   * trace within the native redbox component.
+   */
+  showErrorDialog({componentStack, error: errorValue}: CapturedError): boolean {
+    let error: ?ExtendedError;
+
+    // Typically, `errorValue` should be an error. However, other values such as
+    // strings (or even null) are sometimes thrown.
+    if (errorValue instanceof Error) {
+      error = (errorValue: ExtendedError);
+    } else if (typeof errorValue === 'string') {
+      error = (new SyntheticError(errorValue): ExtendedError);
+    } else {
+      error = (new SyntheticError('Unspecified error'): ExtendedError);
+    }
+    try {
+      error.componentStack = componentStack;
+      error.isComponentError = true;
+    } catch {
+      // Ignored.
+    }
+
+    handleException(error, false);
+
+    // Return false here to prevent ReactFiberErrorLogger default behavior of
+    // logging error details to console.error. Calls to console.error are
+    // automatically routed to the native redbox controller, which we've already
+    // done above by calling ExceptionsManager.
+    return false;
+  },
+};
 
-/**
- * Intercept lifecycle errors and ensure they are shown with the correct stack
- * trace within the native redbox component.
- */
-function showErrorDialog(capturedError: CapturedError): boolean {
-  const {componentStack, error} = capturedError;
-
-  let errorToHandle;
-
-  // Typically Errors are thrown but eg strings or null can be thrown as well.
-  if (error instanceof Error) {
-    errorToHandle = (error: ExtendedError);
-  } else if (typeof error === 'string') {
-    errorToHandle = (new SyntheticError(error): ExtendedError);
-  } else {
-    errorToHandle = (new SyntheticError('Unspecified error'): ExtendedError);
-  }
-  try {
-    errorToHandle.componentStack = componentStack;
-    errorToHandle.isComponentError = true;
-  } catch (e) {}
-  handleException(errorToHandle, false);
-
-  // Return false here to prevent ReactFiberErrorLogger default behavior of
-  // logging error details to console.error. Calls to console.error are
-  // automatically routed to the native redbox controller, which we've already
-  // done above by calling ExceptionsManager.
-  return false;
-}
-
-module.exports = {showErrorDialog};
+export default ReactFiberErrorDialog;

Libraries/Core/__tests__/ExceptionsManager-test.js

@@ -10,6 +10,9 @@
 
 'use strict';
 
+const ExceptionsManager = require('../ExceptionsManager');
+const NativeExceptionsManager = require('../NativeExceptionsManager').default;
+const ReactFiberErrorDialog = require('../ReactFiberErrorDialog').default;
 const fs = require('fs');
 const path = require('path');
 
@@ -23,10 +26,8 @@ const capturedErrorDefaults = {
 };
 
 describe('ExceptionsManager', () => {
-  let ReactFiberErrorDialog,
-    ExceptionsManager,
-    NativeExceptionsManager,
-    nativeReportException;
+  let nativeReportException;
+
   beforeEach(() => {
     jest.resetModules();
     jest.mock('../NativeExceptionsManager', () => {
@@ -46,11 +47,8 @@ describe('ExceptionsManager', () => {
           return {stack};
         },
     );
-    jest.spyOn(console, 'error').mockImplementation(() => {});
-    ReactFiberErrorDialog = require('../ReactFiberErrorDialog');
-    NativeExceptionsManager = require('../NativeExceptionsManager').default;
+    jest.spyOn(console, 'error').mockReturnValue(undefined);
     nativeReportException = NativeExceptionsManager.reportException;
-    ExceptionsManager = require('../ExceptionsManager');
   });
 
   afterEach(() => {

Libraries/ReactPrivate/ReactNativePrivateInterface.js

@@ -58,7 +58,7 @@ module.exports = {
     return require('../StyleSheet/flattenStyle');
   },
   get ReactFiberErrorDialog(): ReactFiberErrorDialog {
-    return require('../Core/ReactFiberErrorDialog');
+    return require('../Core/ReactFiberErrorDialog').default;
   },
   get legacySendAccessibilityEvent(): legacySendAccessibilityEvent {
     return require('../Components/AccessibilityInfo/legacySendAccessibilityEvent');