[Fizz] Minor Fixes for Warning Parity

packages/react-dom/src/__tests__/ReactDOMServerLifecycles-test.js

@@ -115,7 +115,9 @@ describe('ReactDOMServerLifecycles', () => {
       }
     }
 
-    ReactDOMServer.renderToString(<Component />);
+    expect(() => ReactDOMServer.renderToString(<Component />)).toErrorDev(
+      'Unsafe legacy lifecycles will not be called for components using new component APIs.',
+    );
   });
 
   it('should update instance.state with value returned from getDerivedStateFromProps', () => {
@@ -279,8 +281,8 @@ describe('ReactDOMServerLifecycles', () => {
       }
     }
 
-    expect(() => ReactDOMServer.renderToString(<Component />)).toWarnDev(
-      'componentWillMount has been renamed',
+    expect(() => ReactDOMServer.renderToString(<Component />)).toErrorDev(
+      'Unsafe legacy lifecycles will not be called for components using new component APIs.',
     );
   });
 

packages/react-dom/src/server/ReactPartialRenderer.js

@@ -194,6 +194,7 @@ const didWarnAboutModulePatternComponent = {};
 const didWarnAboutDeprecatedWillMount = {};
 const didWarnAboutUndefinedDerivedState = {};
 const didWarnAboutUninitializedState = {};
+const didWarnAboutLegacyLifecyclesAndDerivedState = {};
 const valuePropNames = ['value', 'defaultValue'];
 const newlineEatingTags = {
   listing: true,
@@ -475,6 +476,79 @@ function resolve(
               didWarnAboutUninitializedState[componentName] = true;
             }
           }
+
+          // If new component APIs are defined, "unsafe" lifecycles won't be called.
+          // Warn about these lifecycles if they are present.
+          // Don't warn about react-lifecycles-compat polyfilled methods though.
+          if (
+            typeof Component.getDerivedStateFromProps === 'function' ||
+            typeof inst.getSnapshotBeforeUpdate === 'function'
+          ) {
+            let foundWillMountName = null;
+            let foundWillReceivePropsName = null;
+            let foundWillUpdateName = null;
+            if (
+              typeof inst.componentWillMount === 'function' &&
+              inst.componentWillMount.__suppressDeprecationWarning !== true
+            ) {
+              foundWillMountName = 'componentWillMount';
+            } else if (typeof inst.UNSAFE_componentWillMount === 'function') {
+              foundWillMountName = 'UNSAFE_componentWillMount';
+            }
+            if (
+              typeof inst.componentWillReceiveProps === 'function' &&
+              inst.componentWillReceiveProps.__suppressDeprecationWarning !==
+                true
+            ) {
+              foundWillReceivePropsName = 'componentWillReceiveProps';
+            } else if (
+              typeof inst.UNSAFE_componentWillReceiveProps === 'function'
+            ) {
+              foundWillReceivePropsName = 'UNSAFE_componentWillReceiveProps';
+            }
+            if (
+              typeof inst.componentWillUpdate === 'function' &&
+              inst.componentWillUpdate.__suppressDeprecationWarning !== true
+            ) {
+              foundWillUpdateName = 'componentWillUpdate';
+            } else if (typeof inst.UNSAFE_componentWillUpdate === 'function') {
+              foundWillUpdateName = 'UNSAFE_componentWillUpdate';
+            }
+            if (
+              foundWillMountName !== null ||
+              foundWillReceivePropsName !== null ||
+              foundWillUpdateName !== null
+            ) {
+              const componentName =
+                getComponentNameFromType(Component) || 'Component';
+              const newApiName =
+                typeof Component.getDerivedStateFromProps === 'function'
+                  ? 'getDerivedStateFromProps()'
+                  : 'getSnapshotBeforeUpdate()';
+              if (!didWarnAboutLegacyLifecyclesAndDerivedState[componentName]) {
+                didWarnAboutLegacyLifecyclesAndDerivedState[
+                  componentName
+                ] = true;
+                console.error(
+                  'Unsafe legacy lifecycles will not be called for components using new component APIs.\n\n' +
+                    '%s uses %s but also contains the following legacy lifecycles:%s%s%s\n\n' +
+                    'The above lifecycles should be removed. Learn more about this warning here:\n' +
+                    'https://reactjs.org/link/unsafe-component-lifecycles',
+                  componentName,
+                  newApiName,
+                  foundWillMountName !== null
+                    ? `\n  ${foundWillMountName}`
+                    : '',
+                  foundWillReceivePropsName !== null
+                    ? `\n  ${foundWillReceivePropsName}`
+                    : '',
+                  foundWillUpdateName !== null
+                    ? `\n  ${foundWillUpdateName}`
+                    : '',
+                );
+              }
+            }
+          }
         }
 
         const partialState = Component.getDerivedStateFromProps.call(
@@ -575,32 +649,32 @@ function resolve(
       typeof inst.componentWillMount === 'function'
     ) {
       if (typeof inst.componentWillMount === 'function') {
-        if (__DEV__) {
-          if (
-            warnAboutDeprecatedLifecycles &&
-            inst.componentWillMount.__suppressDeprecationWarning !== true
-          ) {
-            const componentName =
-              getComponentNameFromType(Component) || 'Unknown';
-
-            if (!didWarnAboutDeprecatedWillMount[componentName]) {
-              console.warn(
-                // keep this warning in sync with ReactStrictModeWarning.js
-                'componentWillMount has been renamed, and is not recommended for use. ' +
-                  'See https://reactjs.org/link/unsafe-component-lifecycles for details.\n\n' +
-                  '* Move code from componentWillMount to componentDidMount (preferred in most cases) ' +
-                  'or the constructor.\n' +
-                  '\nPlease update the following components: %s',
-                componentName,
-              );
-              didWarnAboutDeprecatedWillMount[componentName] = true;
-            }
-          }
-        }
-
         // In order to support react-lifecycles-compat polyfilled components,
         // Unsafe lifecycles should not be invoked for any component with the new gDSFP.
         if (typeof Component.getDerivedStateFromProps !== 'function') {
+          if (__DEV__) {
+            if (
+              warnAboutDeprecatedLifecycles &&
+              inst.componentWillMount.__suppressDeprecationWarning !== true
+            ) {
+              const componentName =
+                getComponentNameFromType(Component) || 'Unknown';
+
+              if (!didWarnAboutDeprecatedWillMount[componentName]) {
+                console.warn(
+                  // keep this warning in sync with ReactStrictModeWarning.js
+                  'componentWillMount has been renamed, and is not recommended for use. ' +
+                    'See https://reactjs.org/link/unsafe-component-lifecycles for details.\n\n' +
+                    '* Move code from componentWillMount to componentDidMount (preferred in most cases) ' +
+                    'or the constructor.\n' +
+                    '\nPlease update the following components: %s',
+                  componentName,
+                );
+                didWarnAboutDeprecatedWillMount[componentName] = true;
+              }
+            }
+          }
+
           inst.componentWillMount();
         }
       }

packages/react-server/src/ReactFizzClassComponent.js

@@ -10,13 +10,17 @@
 import {emptyContextObject} from './ReactFizzContext';
 import {readContext} from './ReactFizzNewContext';
 
-import {disableLegacyContext} from 'shared/ReactFeatureFlags';
+import {
+  disableLegacyContext,
+  warnAboutDeprecatedLifecycles,
+} from 'shared/ReactFeatureFlags';
 import {get as getInstance, set as setInstance} from 'shared/ReactInstanceMap';
 import getComponentNameFromType from 'shared/getComponentNameFromType';
 import {REACT_CONTEXT_TYPE, REACT_PROVIDER_TYPE} from 'shared/ReactSymbols';
 import isArray from 'shared/isArray';
 
 const didWarnAboutNoopUpdateForComponent = {};
+const didWarnAboutDeprecatedWillMount = {};
 
 let didWarnAboutUninitializedState;
 let didWarnAboutGetSnapshotBeforeUpdateWithoutDidUpdate;
@@ -531,6 +535,28 @@ function callComponentWillMount(type, instance) {
   const oldState = instance.state;
 
   if (typeof instance.componentWillMount === 'function') {
+    if (__DEV__) {
+      if (
+        warnAboutDeprecatedLifecycles &&
+        instance.componentWillMount.__suppressDeprecationWarning !== true
+      ) {
+        const componentName = getComponentNameFromType(type) || 'Unknown';
+
+        if (!didWarnAboutDeprecatedWillMount[componentName]) {
+          console.warn(
+            // keep this warning in sync with ReactStrictModeWarning.js
+            'componentWillMount has been renamed, and is not recommended for use. ' +
+              'See https://reactjs.org/link/unsafe-component-lifecycles for details.\n\n' +
+              '* Move code from componentWillMount to componentDidMount (preferred in most cases) ' +
+              'or the constructor.\n' +
+              '\nPlease update the following components: %s',
+            componentName,
+          );
+          didWarnAboutDeprecatedWillMount[componentName] = true;
+        }
+      }
+    }
+
     instance.componentWillMount();
   }
   if (typeof instance.UNSAFE_componentWillMount === 'function') {

packages/react-server/src/ReactFizzServer.js

@@ -1032,13 +1032,27 @@ function renderElement(
     }
   }
 
+  let info = '';
+  if (__DEV__) {
+    if (
+      type === undefined ||
+      (typeof type === 'object' &&
+        type !== null &&
+        Object.keys(type).length === 0)
+    ) {
+      info +=
+        ' You likely forgot to export your component from the file ' +
+        "it's defined in, or you might have mixed up default and " +
+        'named imports.';
+    }
+  }
   invariant(
     false,
     'Element type is invalid: expected a string (for built-in ' +
       'components) or a class/function (for composite components) ' +
       'but got: %s.%s',
     type == null ? type : typeof type,
-    '',
+    info,
   );
 }