fix(eslint): remove custom rule in favor of `eslint-plugin-import` (#3012)

Co-authored-by: Sandy Tao <sandytao520@icloud.com>

CONTRIBUTING.md

@@ -210,7 +210,7 @@ npm run lint
 
 - Please adhere to the coding style, patterns, and conventions used throughout the existing codebase.
 - Consult [GEMINI.md](https://github.com/google-gemini/gemini-cli/blob/main/GEMINI.md) (typically found in the project root) for specific instructions related to AI-assisted development, including conventions for React, comments, and Git usage.
-- **Imports:** Pay special attention to import paths. The project uses `eslint-rules/no-relative-cross-package-imports.js` to enforce restrictions on relative imports between packages.
+- **Imports:** Pay special attention to import paths. The project uses ESLint to enforce restrictions on relative imports between packages.
 
 ### Project Structure
 

eslint-rules/no-relative-cross-package-imports.js

@@ -1,159 +0,0 @@
-/**
- * @license
- * Copyright 2025 Google LLC
- * SPDX-License-Identifier: Apache-2.0
- */
-
-/**
- * @fileoverview Disallows relative imports between specified monorepo packages.
- */
-'use strict';
-
-import path from 'node:path';
-import fs from 'node:fs';
-
-/**
- * Finds the package name by searching for the nearest `package.json` file
- * in the directory hierarchy, starting from the given file's directory
- * and moving upwards until the specified root directory is reached.
- * It reads the `package.json` and extracts the `name` property.
- *
- * @requires module:path Node.js path module
- * @requires module:fs Node.js fs module
- *
- * @param {string} filePath - The path (absolute or relative) to a file within the potential package structure.
- * The search starts from the directory containing this file.
- * @param {string} root - The absolute path to the root directory of the project/monorepo.
- * The upward search stops when this directory is reached.
- * @returns {string | undefined | null} The value of the `name` field from the first `package.json` found.
- * Returns `undefined` if the `name` field doesn't exist in the found `package.json`.
- * Returns `null` if no `package.json` is found before reaching the `root` directory.
- * @throws {Error} Can throw an error if `fs.readFileSync` fails (e.g., permissions) or if `JSON.parse` fails on invalid JSON content.
- */
-function findPackageName(filePath, root) {
-  let currentDir = path.dirname(path.resolve(filePath));
-  while (currentDir !== root) {
-    const parentDir = path.dirname(currentDir);
-    const packageJsonPath = path.join(currentDir, 'package.json');
-    if (fs.existsSync(packageJsonPath)) {
-      const pkg = JSON.parse(fs.readFileSync(packageJsonPath, 'utf-8'));
-      return pkg.name;
-    }
-
-    // Move up one level
-    currentDir = parentDir;
-    // Safety break if we somehow reached the root directly in the loop condition (less likely with path.resolve)
-    if (path.dirname(currentDir) === currentDir) break;
-  }
-
-  return null; // Not found within the expected structure
-}
-
-export default {
-  meta: {
-    type: 'problem',
-    docs: {
-      description: 'Disallow relative imports between packages.',
-      category: 'Best Practices',
-      recommended: 'error',
-    },
-    fixable: 'code',
-    schema: [
-      {
-        type: 'object',
-        properties: {
-          root: {
-            type: 'string',
-            description:
-              'Absolute path to the root of all relevant packages to consider.',
-          },
-        },
-        required: ['root'],
-        additionalProperties: false,
-      },
-    ],
-    messages: {
-      noRelativePathsForCrossPackageImport:
-        "Relative import '{{importedPath}}' crosses package boundary from '{{importingPackage}}' to '{{importedPackage}}'. Use a direct package import ('{{importedPackage}}') instead.",
-      relativeImportIsInvalidPackage:
-        "Relative import '{{importedPath}}' does not reference a valid package. All source must be in a package directory.",
-    },
-  },
-
-  create(context) {
-    const options = context.options[0] || {};
-    const allPackagesRoot = options.root;
-
-    const currentFilePath = context.filename;
-    if (
-      !currentFilePath ||
-      currentFilePath === '<input>' ||
-      currentFilePath === '<text>'
-    ) {
-      // Skip if filename is not available (e.g., linting raw text)
-      return {};
-    }
-
-    const currentPackage = findPackageName(currentFilePath, allPackagesRoot);
-
-    // If the current file isn't inside a package structure, don't apply the rule
-    if (!currentPackage) {
-      return {};
-    }
-
-    return {
-      ImportDeclaration(node) {
-        const importingPackage = currentPackage;
-        const importedPath = node.source.value;
-
-        // Only interested in relative paths
-        if (
-          !importedPath ||
-          typeof importedPath !== 'string' ||
-          !importedPath.startsWith('.')
-        ) {
-          return;
-        }
-
-        // Resolve the absolute path of the imported module
-        const absoluteImportPath = path.resolve(
-          path.dirname(currentFilePath),
-          importedPath,
-        );
-
-        // Find the package information for the imported file
-        const importedPackage = findPackageName(
-          absoluteImportPath,
-          allPackagesRoot,
-        );
-
-        // If the imported file isn't in a recognized package, report issue
-        if (!importedPackage) {
-          context.report({
-            node: node.source,
-            messageId: 'relativeImportIsInvalidPackage',
-            data: { importedPath: importedPath },
-          });
-          return;
-        }
-
-        // The core check: Are the source and target packages different?
-        if (currentPackage !== importedPackage) {
-          // We found a relative import crossing package boundaries
-          context.report({
-            node: node.source, // Report the error on the source string literal
-            messageId: 'noRelativePathsForCrossPackageImport',
-            data: {
-              importedPath,
-              importedPackage,
-              importingPackage,
-            },
-            fix(fixer) {
-              return fixer.replaceText(node.source, `'${importedPackage}'`);
-            },
-          });
-        }
-      },
-    };
-  },
-};

eslint.config.js

@@ -12,7 +12,6 @@ import prettierConfig from 'eslint-config-prettier';
 import importPlugin from 'eslint-plugin-import';
 import globals from 'globals';
 import licenseHeader from 'eslint-plugin-license-header';
-import noRelativeCrossPackageImports from './eslint-rules/no-relative-cross-package-imports.js';
 import path from 'node:path'; // Use node: prefix for built-ins
 import url from 'node:url';
 
@@ -34,7 +33,6 @@ export default tseslint.config(
       'packages/core/dist/**',
       'packages/server/dist/**',
       'packages/vscode-ide-companion/dist/**',
-      'eslint-rules/*',
       'bundle/**',
     ],
   },
@@ -72,6 +70,14 @@ export default tseslint.config(
   {
     // General overrides and rules for the project (TS/TSX files)
     files: ['packages/*/src/**/*.{ts,tsx}'], // Target only TS/TSX in the cli package
+    plugins: {
+      import: importPlugin,
+    },
+    settings: {
+      'import/resolver': {
+        node: true,
+      },
+    },
     languageOptions: {
       globals: {
         ...globals.node,
@@ -106,6 +112,13 @@ export default tseslint.config(
           caughtErrorsIgnorePattern: '^_',
         },
       ],
+      'import/no-internal-modules': [
+        'error',
+        {
+          allow: ['react-dom/test-utils', 'memfs/lib/volume.js', 'yargs/**'],
+        },
+      ],
+      'import/no-relative-packages': 'error',
       'no-cond-assign': 'error',
       'no-debugger': 'error',
       'no-duplicate-case': 'error',
@@ -213,24 +226,4 @@ export default tseslint.config(
       ],
     },
   },
-  // Custom eslint rules for this repo
-  {
-    files: ['packages/**/*.{js,jsx,ts,tsx}'],
-    plugins: {
-      custom: {
-        rules: {
-          'no-relative-cross-package-imports': noRelativeCrossPackageImports,
-        },
-      },
-    },
-    rules: {
-      // Enable and configure your custom rule
-      'custom/no-relative-cross-package-imports': [
-        'error',
-        {
-          root: path.join(projectRoot, 'packages'),
-        },
-      ],
-    },
-  },
 );