Improve the error message

facebook · Mar 16, 2020 · e81ae47 · e81ae47
1 parent bed3eb9
commit e81ae47
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Showing 3 changed files with 40 additions and 13 deletions.
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.js b/packages/react-reconciler/src/ReactFiberWorkLoop.js
@@ -2909,20 +2909,36 @@ if (__DEV__ && replayFailedUnitOfWorkWithInvokeGuardedCallback) {
 }
 
 let didWarnAboutUpdateInRender = false;
+let didWarnAboutUpdateInRenderForAnotherComponent;
+if (__DEV__) {
+  didWarnAboutUpdateInRenderForAnotherComponent = new Set();
+}
+
 function warnAboutRenderPhaseUpdatesInDEV(fiber) {
   if (__DEV__) {
     if ((executionContext & RenderContext) !== NoContext) {
       switch (fiber.tag) {
         case FunctionComponent:
         case ForwardRef:
         case SimpleMemoComponent: {
-          console.error(
-            'Cannot update a component from inside the function body of a ' +
-              'different component.\n' +
-              '"%s" updated "%s".',
-            workInProgress && getComponentName(workInProgress.type),
-            getComponentName(fiber.type),
-          );
+          const renderingComponentName =
+            (workInProgress && getComponentName(workInProgress.type)) ||
+            'Unknown';
+          const setStateComponentName =
+            getComponentName(fiber.type) || 'Unknown';
+          const dedupeKey =
+            renderingComponentName + ' ' + setStateComponentName;
+          if (!didWarnAboutUpdateInRenderForAnotherComponent.has(dedupeKey)) {
+            didWarnAboutUpdateInRenderForAnotherComponent.add(dedupeKey);
+            console.error(
+              'Cannot update a component (`%s`) from inside the function body of a ' +
+                'different component (`%s`). To locate the bad setState() call inside `%s`, ' +
+                'follow the stack trace as described in https://fb.me/setstate-in-render',
+              setStateComponentName,
+              renderingComponentName,
+              renderingComponentName,
+            );
+          }
           break;
         }
         case ClassComponent: {

diff --git a/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js b/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js
@@ -1087,7 +1087,7 @@ describe('ReactHooks', () => {
       ),
     ).toErrorDev([
       'Context can only be read while React is rendering',
-      'Cannot update a component from inside the function body of a different component.\n"Cls" updated "Fn".',
+      'Cannot update a component (`Fn`) from inside the function body of a different component (`Cls`).',
     ]);
   });
 
@@ -1783,8 +1783,8 @@ describe('ReactHooks', () => {
     if (__DEV__) {
       expect(console.error).toHaveBeenCalledTimes(2);
       expect(console.error.calls.argsFor(0)[0]).toContain(
-        'Warning: Cannot update a component from inside the function body ' +
-          'of a different component.\n"%s" updated "%s".%s',
+        'Warning: Cannot update a component (`%s`) from inside the function body ' +
+          'of a different component (`%s`).',
       );
     }
   });

diff --git a/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.internal.js b/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.internal.js
@@ -412,7 +412,7 @@ describe('ReactHooksWithNoopRenderer', () => {
 
       function Bar({triggerUpdate}) {
         if (triggerUpdate) {
-          setStep(1);
+          setStep(x => x + 1);
         }
         return <Text text="Bar" />;
       }
@@ -440,10 +440,21 @@ describe('ReactHooksWithNoopRenderer', () => {
         expect(() =>
           expect(Scheduler).toFlushAndYield(['Foo [0]', 'Bar', 'Foo [1]']),
         ).toErrorDev([
-          'Cannot update a component from inside the function body of a ' +
-            'different component.\n"Bar" updated "Foo".',
+          'Cannot update a component (`Foo`) from inside the function body of a ' +
+            'different component (`Bar`). To locate the bad setState() call inside `Bar`',
         ]);
       });
+
+      // It should not warn again (deduplication).
+      await ReactNoop.act(async () => {
+        root.render(
+          <>
+            <Foo />
+            <Bar triggerUpdate={true} />
+          </>,
+        );
+        expect(Scheduler).toFlushAndYield(['Foo [1]', 'Bar', 'Foo [2]']);
+      });
     });
 
     it('keeps restarting until there are no more new updates', () => {