FPFNFIXAPEX avoid empty-default warnings for imported plain class projections

.changeset/imported-plain-class-empty-default.md

@@ -0,0 +1,7 @@
+---
+"oxlint-plugin-react-doctor": patch
+"eslint-plugin-react-doctor": patch
+"react-doctor": patch
+---
+
+Avoid reporting empty object defaults passed only to imported plain classes that read their members without observing the object identity.

packages/fuzz/corpus/regressions/imported-plain-class-member-projection/child.jsx

@@ -0,0 +1,8 @@
+import { Component } from "react";
+
+export default class Child extends Component {
+  render() {
+    const { config: { Slot = "span" } = {} } = this.props;
+    return <Slot />;
+  }
+}

packages/fuzz/corpus/regressions/imported-plain-class-member-projection/entry.tsx

@@ -0,0 +1,8 @@
+// rule: rerender-memo-with-default-value
+// weakness: cross-file
+// source: synthetic imported plain class member projection
+// verdict: pass
+// file-path: corpus/regressions/imported-plain-class-member-projection/entry.tsx
+import Child from "./child.jsx";
+
+export const App = ({ config = {} }) => <Child config={config} />;

packages/fuzz/corpus/regressions/imported-plain-class-member-projection/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "private-imported-plain-class-fixture",
+  "private": true,
+  "type": "module",
+  "dependencies": {
+    "react": "19.2.0"
+  }
+}

packages/oxlint-plugin-react-doctor/src/plugin/constants/react.ts

@@ -521,3 +521,50 @@ export const REACT_JSX_PROVIDER_MODULE_SOURCES: ReadonlySet<string> = new Set([
   "react/jsx-runtime",
   "react/jsx-dev-runtime",
 ]);
+
+export const IMPORTED_CLASS_PASSIVE_VALIDATOR_NAMES: ReadonlySet<string> = new Set([
+  "any",
+  "array",
+  "func",
+  "object",
+]);
+
+export const IMPORTED_CLASS_REFUSED_MEMBER_NAMES: ReadonlySet<string> = new Set([
+  ...REACT_PROVIDER_MUTATION_CAPABILITY_NAMES,
+  "constructor",
+  "defineProperty",
+  "defineProperties",
+  "setPrototypeOf",
+  "__lookupGetter__",
+  "__lookupSetter__",
+]);
+
+export const IMPORTED_CLASS_REFUSED_MODULE_SOURCES: ReadonlySet<string> = new Set([
+  "module",
+  "node:module",
+  "vm",
+  "node:vm",
+]);
+
+export const IMPORTED_CLASS_REFUSED_GLOBAL_NAMES: ReadonlySet<string> = new Set([
+  "React",
+  "eval",
+  "Function",
+  "Reflect",
+]);
+
+export const IMPORTED_CLASS_CANONICAL_MODULE_SOURCES: ReadonlySet<string> = new Set([
+  ...REACT_JSX_PROVIDER_MODULE_SOURCES,
+  "prop-types",
+]);
+
+export const IMPORTED_CLASS_PASSIVE_OBJECT_METHOD_NAMES: ReadonlySet<string> = new Set([
+  "keys",
+  "entries",
+]);
+
+export const IMPORTED_CLASS_INSTANCE_MUTATION_NAMES: ReadonlySet<string> = new Set([
+  "render",
+  "shouldComponentUpdate",
+  "isRequired",
+]);

packages/oxlint-plugin-react-doctor/src/plugin/cross-file-dependencies.ts

@@ -469,6 +469,26 @@ const collectForwardedHookDependencies: CrossFileDependencyCollector = (input) =
   if (hasDestructuredHookCandidate) return false;
 };
 
+const collectMemoDefaultDependencies: CrossFileDependencyCollector = (input) => {
+  if (collectForwardedHookDependencies(input) === false) return false;
+  if (
+    !flattenImportEntries(input.staticImports).some(
+      (entry) => entry.source.startsWith(".") && entry.exportedName === "default",
+    )
+  )
+    return;
+  let hasEmptyObjectDefault = false;
+  walkAst(input.getProgram(), (node) => {
+    if (
+      isNodeOfType(node, "AssignmentPattern") &&
+      isNodeOfType(node.right, "ObjectExpression") &&
+      node.right.properties.length === 0
+    )
+      hasEmptyObjectDefault = true;
+  });
+  if (hasEmptyObjectDefault) return false;
+};
+
 const collectCreateRefDependencies: CrossFileDependencyCollector = ({
   absoluteFilePath,
   sourceText,
@@ -732,7 +752,7 @@ export const CROSS_FILE_DEPENDENCY_COLLECTORS: ReadonlyMap<string, CrossFileDepe
     ["prefer-dynamic-import", collectNearestManifestDependencies],
     ["rendering-hydration-mismatch-time", collectNearestManifestDependencies],
     ["rendering-hydration-no-flicker", collectEffectValueHelperDependencies],
-    ["rerender-memo-with-default-value", collectForwardedHookDependencies],
+    ["rerender-memo-with-default-value", collectMemoDefaultDependencies],
     ["server-sequential-independent-await", collectSequentialAwaitDependencies],
     ["rn-no-deprecated-modules", collectReactNativeVersionDependencies],
     ["rn-no-legacy-shadow-styles", collectLegacyArchDependencies],