make digest a public api on the Error value

Author: gnoff

packages/react-client/src/ReactFlightClient.js

@@ -193,7 +193,7 @@ function createBlockedChunk<T>(response: Response): BlockedChunk<T> {
 
 function createErrorChunk<T>(
   response: Response,
-  error: Error,
+  error: ErrorWithDigest,
 ): ErroredChunk<T> {
   // $FlowFixMe Flow doesn't support functions as constructors
   return new Chunk(ERRORED, null, error, response);
@@ -628,7 +628,7 @@ export function resolveSymbol(
   chunks.set(id, createInitializedChunk(response, Symbol.for(name)));
 }
 
-type ErrorWithDigest = Error & {_digest?: string};
+type ErrorWithDigest = Error & {digest?: string};
 export function resolveErrorProd(
   response: Response,
   id: number,
@@ -641,9 +641,13 @@ export function resolveErrorProd(
       'resolveErrorProd should never be called in development mode. Use resolveErrorDev instead. This is a bug in React.',
     );
   }
-  const error = new Error('An error occurred in the Server Components render.');
+  const error = new Error(
+    'An error occurred in the Server Components render. The specific message is omitted in production' +
+      ' builds to avoid leaking sensitive details. A digest property is included on this error instance which' +
+      ' may provide additional details about the nature of the error.',
+  );
   error.stack = '';
-  (error: any)._digest = digest;
+  (error: any).digest = digest;
   const errorWithDigest: ErrorWithDigest = (error: any);
   const chunks = response._chunks;
   const chunk = chunks.get(id);
@@ -674,7 +678,7 @@ export function resolveErrorDev(
       'An error occurred in the Server Components render but no message was provided',
   );
   error.stack = stack;
-  (error: any)._digest = digest;
+  (error: any).digest = digest;
   const errorWithDigest: ErrorWithDigest = (error: any);
   const chunks = response._chunks;
   const chunk = chunks.get(id);

packages/react-client/src/__tests__/ReactFlight-test.js

@@ -49,14 +49,12 @@ describe('ReactFlight', () => {
           expect(this.state.error.message).toContain(
             this.props.expectedMessage,
           );
-          expect(this.state.error._digest).toBe('a dev digest');
+          expect(this.state.error.digest).toBe('a dev digest');
         } else {
           expect(this.state.error.message).toBe(
             'An error occurred in the Server Components render.',
           );
-          expect(this.state.error._digest).toContain(
-            this.props.expectedMessage,
-          );
+          expect(this.state.error.digest).toContain(this.props.expectedMessage);
         }
       }
       render() {

packages/react-server-dom-webpack/src/__tests__/ReactFlightDOM-test.js

@@ -336,7 +336,7 @@ describe('ReactFlightDOM', () => {
           fallback={e => (
             <p>
               {__DEV__ ? e.message + ' + ' : null}
-              {e._digest}
+              {e.digest}
             </p>
           )}>
           {children}
@@ -642,7 +642,7 @@ describe('ReactFlightDOM', () => {
           fallback={e => (
             <p>
               {__DEV__ ? e.message + ' + ' : null}
-              {e._digest}
+              {e.digest}
             </p>
           )}>
           <Suspense fallback={<p>(loading)</p>}>
@@ -818,7 +818,7 @@ describe('ReactFlightDOM', () => {
           fallback={e => (
             <p>
               {__DEV__ ? e.message + ' + ' : null}
-              {e._digest}
+              {e.digest}
             </p>
           )}>
           <Suspense fallback={<p>(loading)</p>}>

packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMBrowser-test.js

@@ -177,15 +177,15 @@ describe('ReactFlightDOMBrowser', () => {
     if (__DEV__) {
       errorBoundaryFn = e => (
         <p>
-          {e.message} + {e._digest}
+          {e.message} + {e.digest}
         </p>
       );
     } else {
       errorBoundaryFn = e => {
         expect(e.message).toBe(
           'An error occurred in the Server Components render.',
         );
-        return <p>{e._digest}</p>;
+        return <p>{e.digest}</p>;
       };
     }
 
@@ -513,15 +513,15 @@ describe('ReactFlightDOMBrowser', () => {
     if (__DEV__) {
       errorBoundaryFn = e => (
         <p>
-          {e.message} + {e._digest}
+          {e.message} + {e.digest}
         </p>
       );
     } else {
       errorBoundaryFn = e => {
         expect(e.message).toBe(
           'An error occurred in the Server Components render.',
         );
-        return <p>{e._digest}</p>;
+        return <p>{e.digest}</p>;
       };
     }
 
@@ -720,8 +720,8 @@ describe('ReactFlightDOMBrowser', () => {
       render() {
         if (this.state.error) {
           return __DEV__
-            ? this.state.error.message + ' + ' + this.state.error._digest
-            : this.state.error._digest;
+            ? this.state.error.message + ' + ' + this.state.error.digest
+            : this.state.error.digest;
         }
         return this.props.children;
       }