fix: apply monorepo root react-doctor config to workspace package scans

packages/react-doctor/src/utils/load-config.ts

@@ -1,14 +1,15 @@
 import fs from "node:fs";
 import path from "node:path";
 import type { ReactDoctorConfig } from "../types.js";
+import { findMonorepoRoot } from "./find-monorepo-root.js";
 import { isFile } from "./is-file.js";
 import { isPlainObject } from "./is-plain-object.js";
 
 const CONFIG_FILENAME = "react-doctor.config.json";
 const PACKAGE_JSON_CONFIG_KEY = "reactDoctor";
 
-export const loadConfig = (rootDirectory: string): ReactDoctorConfig | null => {
-  const configFilePath = path.join(rootDirectory, CONFIG_FILENAME);
+const loadDirectoryConfig = (directory: string): ReactDoctorConfig | null => {
+  const configFilePath = path.join(directory, CONFIG_FILENAME);
 
   if (isFile(configFilePath)) {
     try {
@@ -25,7 +26,7 @@ export const loadConfig = (rootDirectory: string): ReactDoctorConfig | null => {
     }
   }
 
-  const packageJsonPath = path.join(rootDirectory, "package.json");
+  const packageJsonPath = path.join(directory, "package.json");
   if (isFile(packageJsonPath)) {
     try {
       const fileContent = fs.readFileSync(packageJsonPath, "utf-8");
@@ -41,3 +42,17 @@ export const loadConfig = (rootDirectory: string): ReactDoctorConfig | null => {
 
   return null;
 };
+
+export const loadConfig = (rootDirectory: string): ReactDoctorConfig | null => {
+  const localConfig = loadDirectoryConfig(rootDirectory);
+  if (localConfig) {
+    return localConfig;
+  }
+
+  const monorepoRoot = findMonorepoRoot(rootDirectory);
+  if (!monorepoRoot || monorepoRoot === rootDirectory) {
+    return null;
+  }
+
+  return loadDirectoryConfig(monorepoRoot);
+};

packages/react-doctor/tests/load-config.test.ts

@@ -93,6 +93,56 @@ describe("loadConfig", () => {
     });
   });
 
+  describe("monorepo root fallback", () => {
+    it("loads monorepo root config when workspace package has no local config", () => {
+      const monorepoRoot = path.join(tempRootDirectory, "monorepo-root-fallback");
+      const workspaceDirectory = path.join(monorepoRoot, "packages", "app");
+
+      fs.mkdirSync(workspaceDirectory, { recursive: true });
+      fs.writeFileSync(
+        path.join(monorepoRoot, "package.json"),
+        JSON.stringify({ name: "workspace-root", workspaces: ["packages/*"] }),
+      );
+      fs.writeFileSync(
+        path.join(monorepoRoot, "react-doctor.config.json"),
+        JSON.stringify({ ignore: { rules: ["jsx-a11y/alt-text"] } }),
+      );
+      fs.writeFileSync(
+        path.join(workspaceDirectory, "package.json"),
+        JSON.stringify({ name: "app" }),
+      );
+
+      const config = loadConfig(workspaceDirectory);
+      expect(config).toEqual({ ignore: { rules: ["jsx-a11y/alt-text"] } });
+    });
+
+    it("prefers workspace-local config over monorepo root fallback", () => {
+      const monorepoRoot = path.join(tempRootDirectory, "monorepo-local-precedence");
+      const workspaceDirectory = path.join(monorepoRoot, "packages", "app");
+
+      fs.mkdirSync(workspaceDirectory, { recursive: true });
+      fs.writeFileSync(
+        path.join(monorepoRoot, "package.json"),
+        JSON.stringify({ name: "workspace-root", workspaces: ["packages/*"] }),
+      );
+      fs.writeFileSync(
+        path.join(monorepoRoot, "react-doctor.config.json"),
+        JSON.stringify({ ignore: { rules: ["from-root"] } }),
+      );
+      fs.writeFileSync(
+        path.join(workspaceDirectory, "package.json"),
+        JSON.stringify({ name: "app" }),
+      );
+      fs.writeFileSync(
+        path.join(workspaceDirectory, "react-doctor.config.json"),
+        JSON.stringify({ ignore: { rules: ["from-workspace"] } }),
+      );
+
+      const config = loadConfig(workspaceDirectory);
+      expect(config).toEqual({ ignore: { rules: ["from-workspace"] } });
+    });
+  });
+
   describe("no config", () => {
     let emptyDirectory: string;