fix: Forbid self package import

.eslintrc.js

@@ -1,6 +1,8 @@
 module.exports = {
   root: true,
   extends: ['@deephaven/eslint-config'],
+  // The `deephaven` eslint plugin is defined in `packages/eslint-config/plugin`
+  plugins: ['deephaven'],
   ignorePatterns: ['packages/golden-layout/*', 'jest.config.*'],
   overrides: [
     {
@@ -9,6 +11,9 @@ module.exports = {
         project: ['./tsconfig.eslint.json', './packages/*/tsconfig.json'],
         tsconfigRootDir: __dirname,
       },
+      rules: {
+        'deephaven/no-self-package-import': 'error',
+      },
     },
   ],
 };

packages/eslint-config/README.md

@@ -16,6 +16,25 @@ In your package.json, add a `eslintConfig` configuration:
 "eslintConfig": { "extends": "@deephaven/eslint-config" }
 ```
 
+## Deephaven Eslint Plugin (eslint-plugin-deephaven)
+The `deephaven` eslint plugin is defined inside of the `plugin` folder. There is
+a `devDependency` mapping in `package.json` which allows it to be consumed in an
+eslint config file using the name `deephaven`.
+
+```json
+"devDependencies": {
+  "eslint-plugin-deephaven": "file:./plugin"
+},
+```
+
+e.g.
+```javascript
+module.exports = {
+  root: true,
+  plugins: ['deephaven'],
+}
+```
+
 # Legal Notices
 
 Deephaven Data Labs and any contributors grant you a license to the content of this repository under the Apache 2.0 License, see the [LICENSE](../../LICENSE) file.

packages/eslint-config/package.json

@@ -14,6 +14,9 @@
     "eslint-config-prettier": "8.3.0",
     "eslint-config-react-app": "7.0.0"
   },
+  "devDependencies": {
+    "eslint-plugin-deephaven": "file:./plugin"
+  },
   "peerDependencies": {
     "@typescript-eslint/eslint-plugin": "^5.46.0",
     "@typescript-eslint/parser": "^5.46.0",

packages/eslint-config/plugin/index.js

@@ -0,0 +1,7 @@
+const noSelfPackageImportRule = require('./no-self-package-import');
+
+const plugin = {
+  rules: { 'no-self-package-import': noSelfPackageImportRule },
+};
+
+module.exports = plugin;

packages/eslint-config/plugin/no-self-package-import.js

@@ -0,0 +1,60 @@
+/**
+ * Derive the `@deephaven` package name from the given path.
+ * Note that this assumes that the package folder name uses the same naming
+ * convention as the package.json `name` field.
+ */
+function deriveDeephavenPackageNameFromPath(path) {
+  // In the off chance that there is a packages folder higher up in the path,
+  // find the deepest one.
+  const packageFolderNameI = path.lastIndexOf('packages');
+
+  if (packageFolderNameI === -1) {
+    return null;
+  }
+
+  // Find the path token immediately after the `packages` folder.
+  const [packageFolderName] = path
+    .substring(packageFolderNameI + 'packages'.length + 1)
+    .split('/');
+
+  if (packageFolderName === '') {
+    return null;
+  }
+
+  return `@deephaven/${packageFolderName}`;
+}
+
+/**
+ * Custom eslint rule that forbids importing from the same `@deephaven` package
+ * that owns the module. Note that this rule is only useful within the `@deephaven`
+ * web-client-ui monorepo.
+ */
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description:
+        'Forbid importing from the same `@deephaven` package that owns this module.',
+    },
+  },
+  create: function create(context) {
+    const filePath = context.getFilename();
+
+    const packageName = deriveDeephavenPackageNameFromPath(filePath);
+    if (packageName == null) {
+      return {};
+    }
+
+    return {
+      ImportDeclaration(node) {
+        if (node.source.value.includes(packageName)) {
+          context.report({
+            node,
+            message:
+              'Forbid importing from the same `@deephaven` package that owns this module.',
+          });
+        }
+      },
+    };
+  },
+};

packages/jsapi-utils/src/SessionUtils.ts

@@ -5,12 +5,9 @@ import type {
   IdeConnection,
   IdeSession,
 } from '@deephaven/jsapi-types';
-import {
-  requestParentResponse,
-  SESSION_DETAILS_REQUEST,
-} from '@deephaven/jsapi-utils';
 import Log from '@deephaven/log';
 import shortid from 'shortid';
+import { requestParentResponse, SESSION_DETAILS_REQUEST } from './MessageUtils';
 import NoConsolesError, { isNoConsolesError } from './NoConsolesError';
 
 const log = Log.module('SessionUtils');