Remove defaultProps support (except for classes) (#28733)

This removes defaultProps support for all component types except for classes. We've chosen to continue supporting defaultProps for classes because lots of older code relies on it, and unlike function components, (which can use default params), there's no straightforward alternative. By implication, it also removes support for setting defaultProps on `React.lazy` wrapper. So this will not work: ```js const MyClassComponent = React.lazy(() => import('./MyClassComponent')); // MyClassComponent is not actually a class; it's a lazy wrapper. So // defaultProps does not work. MyClassComponent.defaultProps = { foo: 'bar' }; ``` However, if you set the default props on the class itself, then it's fine. For classes, this change also moves where defaultProps are resolved. Previously, defaultProps were resolved by the JSX runtime. This change is only observable if you introspect a JSX element, which is relatively rare but does happen. In other words, previously `<ClassWithDefaultProp />.props.aDefaultProp` would resolve to the default prop value, but now it does not. DiffTrain build for [48b4ecc](48b4ecc)
facebook · Apr 4, 2024 · 769be69 · 769be69
1 parent e0fc90e
commit 769be69
Show file tree

Hide file tree

Showing 34 changed files with 1,691 additions and 1,052 deletions.
diff --git a/compiled/facebook-www/JSXDEVRuntime-dev.classic.js b/compiled/facebook-www/JSXDEVRuntime-dev.classic.js
@@ -109,8 +109,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
 
     function getWrappedName(outerType, innerType, wrapperName) {
       var displayName = outerType.displayName;
@@ -1231,14 +1232,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }

diff --git a/compiled/facebook-www/JSXDEVRuntime-dev.modern.js b/compiled/facebook-www/JSXDEVRuntime-dev.modern.js
@@ -109,8 +109,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
 
     function getWrappedName(outerType, innerType, wrapperName) {
       var displayName = outerType.displayName;
@@ -1231,14 +1232,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }

diff --git a/compiled/facebook-www/REVISION b/compiled/facebook-www/REVISION
@@ -1 +1 @@
-6090cab099a8f7f373e04c7eb2937425a8f80f80
+48b4ecc9012638ed51b275aad24b2086b8215e32
diff --git a/compiled/facebook-www/React-dev.classic.js b/compiled/facebook-www/React-dev.classic.js
@@ -24,7 +24,7 @@ if (__DEV__) {
     ) {
       __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error());
     }
-    var ReactVersion = "19.0.0-www-classic-308d9210";
+    var ReactVersion = "19.0.0-www-classic-b9e0eea7";
 
     // ATTENTION
     // When adding new symbols to this file,
@@ -475,8 +475,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, false is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, false is used for a new modern build.
     var disableLegacyMode = false;
 
     function getWrappedName(outerType, innerType, wrapperName) {
@@ -1639,14 +1640,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
@@ -1906,7 +1910,11 @@ if (__DEV__) {
 
         var defaultProps;
 
-        if (element.type && element.type.defaultProps) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          element.type &&
+          element.type.defaultProps
+        ) {
           defaultProps = element.type.defaultProps;
         }
 
@@ -1926,7 +1934,11 @@ if (__DEV__) {
             // backwards compatibility.
             !(enableRefAsProp && propName === "ref" && config.ref === undefined)
           ) {
-            if (config[propName] === undefined && defaultProps !== undefined) {
+            if (
+              !disableDefaultPropsExceptForClasses &&
+              config[propName] === undefined &&
+              defaultProps !== undefined
+            ) {
               // Resolve default props
               props[propName] = defaultProps[propName];
             } else {
@@ -2765,55 +2777,35 @@ if (__DEV__) {
         _init: lazyInitializer
       };
 
-      {
-        // In production, this would just set it on the object.
-        var defaultProps;
-        var propTypes; // $FlowFixMe[prop-missing]
-
-        Object.defineProperties(lazyType, {
-          defaultProps: {
-            configurable: true,
-            get: function () {
-              return defaultProps;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newDefaultProps) {
-              error(
-                "It is not supported to assign `defaultProps` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
-
-              defaultProps = newDefaultProps; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+      if (!disableDefaultPropsExceptForClasses) {
+        {
+          // In production, this would just set it on the object.
+          var defaultProps; // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "defaultProps", {
-                enumerable: true
-              });
-            }
-          },
-          propTypes: {
-            configurable: true,
-            get: function () {
-              return propTypes;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newPropTypes) {
-              error(
-                "It is not supported to assign `propTypes` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
+          Object.defineProperties(lazyType, {
+            defaultProps: {
+              configurable: true,
+              get: function () {
+                return defaultProps;
+              },
+              // $FlowFixMe[missing-local-annot]
+              set: function (newDefaultProps) {
+                error(
+                  "It is not supported to assign `defaultProps` to " +
+                    "a lazy component import. Either specify them where the component " +
+                    "is defined, or create a wrapping component around it."
+                );
 
-              propTypes = newPropTypes; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+                defaultProps = newDefaultProps; // Match production behavior more closely:
+                // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "propTypes", {
-                enumerable: true
-              });
+                Object.defineProperty(lazyType, "defaultProps", {
+                  enumerable: true
+                });
+              }
             }
-          }
-        });
+          });
+        }
       }
 
       return lazyType;

diff --git a/compiled/facebook-www/React-dev.modern.js b/compiled/facebook-www/React-dev.modern.js
@@ -24,7 +24,7 @@ if (__DEV__) {
     ) {
       __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error());
     }
-    var ReactVersion = "19.0.0-www-modern-3e52800d";
+    var ReactVersion = "19.0.0-www-modern-3a8173ed";
 
     // ATTENTION
     // When adding new symbols to this file,
@@ -475,8 +475,9 @@ if (__DEV__) {
     var enableDebugTracing = dynamicFeatureFlags.enableDebugTracing,
       enableTransitionTracing = dynamicFeatureFlags.enableTransitionTracing,
       enableRenderableContext = dynamicFeatureFlags.enableRenderableContext,
-      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp;
-    // On WWW, true is used for a new modern build.
+      enableRefAsProp = dynamicFeatureFlags.enableRefAsProp,
+      disableDefaultPropsExceptForClasses =
+        dynamicFeatureFlags.disableDefaultPropsExceptForClasses; // On WWW, true is used for a new modern build.
     var disableLegacyMode = true;
 
     function getWrappedName(outerType, innerType, wrapperName) {
@@ -1639,14 +1640,17 @@ if (__DEV__) {
           ) {
             props[propName] = config[propName];
           }
-        } // Resolve default props
+        }
 
-        if (type && type.defaultProps) {
-          var defaultProps = type.defaultProps;
+        if (!disableDefaultPropsExceptForClasses) {
+          // Resolve default props
+          if (type && type.defaultProps) {
+            var defaultProps = type.defaultProps;
 
-          for (propName in defaultProps) {
-            if (props[propName] === undefined) {
-              props[propName] = defaultProps[propName];
+            for (propName in defaultProps) {
+              if (props[propName] === undefined) {
+                props[propName] = defaultProps[propName];
+              }
             }
           }
         }
@@ -1906,7 +1910,11 @@ if (__DEV__) {
 
         var defaultProps;
 
-        if (element.type && element.type.defaultProps) {
+        if (
+          !disableDefaultPropsExceptForClasses &&
+          element.type &&
+          element.type.defaultProps
+        ) {
           defaultProps = element.type.defaultProps;
         }
 
@@ -1926,7 +1934,11 @@ if (__DEV__) {
             // backwards compatibility.
             !(enableRefAsProp && propName === "ref" && config.ref === undefined)
           ) {
-            if (config[propName] === undefined && defaultProps !== undefined) {
+            if (
+              !disableDefaultPropsExceptForClasses &&
+              config[propName] === undefined &&
+              defaultProps !== undefined
+            ) {
               // Resolve default props
               props[propName] = defaultProps[propName];
             } else {
@@ -2765,55 +2777,35 @@ if (__DEV__) {
         _init: lazyInitializer
       };
 
-      {
-        // In production, this would just set it on the object.
-        var defaultProps;
-        var propTypes; // $FlowFixMe[prop-missing]
-
-        Object.defineProperties(lazyType, {
-          defaultProps: {
-            configurable: true,
-            get: function () {
-              return defaultProps;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newDefaultProps) {
-              error(
-                "It is not supported to assign `defaultProps` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
-
-              defaultProps = newDefaultProps; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+      if (!disableDefaultPropsExceptForClasses) {
+        {
+          // In production, this would just set it on the object.
+          var defaultProps; // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "defaultProps", {
-                enumerable: true
-              });
-            }
-          },
-          propTypes: {
-            configurable: true,
-            get: function () {
-              return propTypes;
-            },
-            // $FlowFixMe[missing-local-annot]
-            set: function (newPropTypes) {
-              error(
-                "It is not supported to assign `propTypes` to " +
-                  "a lazy component import. Either specify them where the component " +
-                  "is defined, or create a wrapping component around it."
-              );
+          Object.defineProperties(lazyType, {
+            defaultProps: {
+              configurable: true,
+              get: function () {
+                return defaultProps;
+              },
+              // $FlowFixMe[missing-local-annot]
+              set: function (newDefaultProps) {
+                error(
+                  "It is not supported to assign `defaultProps` to " +
+                    "a lazy component import. Either specify them where the component " +
+                    "is defined, or create a wrapping component around it."
+                );
 
-              propTypes = newPropTypes; // Match production behavior more closely:
-              // $FlowFixMe[prop-missing]
+                defaultProps = newDefaultProps; // Match production behavior more closely:
+                // $FlowFixMe[prop-missing]
 
-              Object.defineProperty(lazyType, "propTypes", {
-                enumerable: true
-              });
+                Object.defineProperty(lazyType, "defaultProps", {
+                  enumerable: true
+                });
+              }
             }
-          }
-        });
+          });
+        }
       }
 
       return lazyType;