React Native fixes for new inline errors feature (facebook#20502)

Author: Brian Vaughn

packages/react-devtools-shared/src/__tests__/inspectedElementContext-test.js

@@ -2014,7 +2014,8 @@ describe('InspectedElementContext', () => {
         Object {
           "errors": Array [
             Array [
-              "Warning: Each child in a list should have a unique \\"key\\" prop. See https://reactjs.org/link/warning-keys for more information.",
+              "Warning: Each child in a list should have a unique \\"key\\" prop. See https://reactjs.org/link/warning-keys for more information.
+            at Example",
               1,
             ],
           ],

packages/react-devtools-shared/src/backend/console.js

@@ -140,12 +140,12 @@ export function patch({
         targetConsole[method]);
 
       const overrideMethod = (...args) => {
-        const lastArg = args.length > 0 ? args[args.length - 1] : null;
-        const alreadyHasComponentStack =
-          lastArg !== null && isStringComponentStack(lastArg);
-
         let shouldAppendWarningStack = false;
         if (consoleSettingsRef.appendComponentStack) {
+          const lastArg = args.length > 0 ? args[args.length - 1] : null;
+          const alreadyHasComponentStack =
+            lastArg !== null && isStringComponentStack(lastArg);
+
           // If we are ever called with a string that already has a component stack,
           // e.g. a React error/warning, don't append a second stack.
           shouldAppendWarningStack = !alreadyHasComponentStack;
@@ -176,10 +176,7 @@ export function patch({
                       current,
                       ((method: any): 'error' | 'warn'),
                       // Copy args before we mutate them (e.g. adding the component stack)
-                      alreadyHasComponentStack
-                        ? // Replace component stack with an empty string in case there's a string placeholder for it.
-                          [...args.slice(0, -1), '']
-                        : args.slice(),
+                      args.slice(),
                     );
                   }
                 }

packages/react-devtools-shared/src/backend/renderer.js

@@ -634,7 +634,7 @@ export function attach(
     const breakOnConsoleErrors =
       window.__REACT_DEVTOOLS_BREAK_ON_CONSOLE_ERRORS__ === true;
     const showInlineWarningsAndErrors =
-      window.__REACT_DEVTOOLS_SHOW_INLINE_WARNINGS_AND_ERRORS__ === true;
+      window.__REACT_DEVTOOLS_SHOW_INLINE_WARNINGS_AND_ERRORS__ !== false;
     if (appendComponentStack || breakOnConsoleErrors) {
       patchConsole({
         appendComponentStack,

packages/react-devtools-shared/src/hook.js

@@ -183,7 +183,7 @@ export function installHook(target: any): DevToolsHook | null {
         const breakOnConsoleErrors =
           window.__REACT_DEVTOOLS_BREAK_ON_CONSOLE_ERRORS__ === true;
         const showInlineWarningsAndErrors =
-          window.__REACT_DEVTOOLS_SHOW_INLINE_WARNINGS_AND_ERRORS__ === true;
+          window.__REACT_DEVTOOLS_SHOW_INLINE_WARNINGS_AND_ERRORS__ !== false;
 
         // The installHook() function is injected by being stringified in the browser,
         // so imports outside of this function do not get included.