feat: support chains started of helper functions in unsafe-to-chain-command

README.md

@@ -139,6 +139,46 @@ export default defineConfig([
 ])
 ```
 
+### Typed Linting
+
+You can activate typed linting for increased accuracy, if you want. This is purely optional and all rules continue to work without it. It uses a TypeScript parser to parse your entire project, instead of only the file being linted, which gives the plugin more information to work with. Be aware of the [performance penalty](https://typescript-eslint.io/getting-started/typed-linting/#performance) that this brings with it.
+
+First, install the `typescript-eslint` npm package:
+
+```sh
+npm install typescript-eslint --save-dev
+```
+
+If you already have a TypeScript codebase, you can skip the next step. If not, you need a `tsconfig.json`. The following minimal `tsconfig.json` does not compile or check your code and includes all .js files.
+
+```json
+{
+  "include": ["**/*.js"],
+  "compilerOptions": {
+    "allowJs": true,
+    "checkJs": false,
+    "noEmit": true
+  },
+}
+```
+
+The last step is to extend your eslint config to use the `typescript-eslint` parser.
+
+```js
+import { defineConfig } from 'eslint/config'
+import typescriptParser from '@typescript-eslint/parser'
+export default defineConfig([
+  {
+    languageOptions: {
+      parser: typescriptParser,
+      parserOptions: {
+        projectService: true,
+      },
+    },
+  }
+])
+```
+
 ## Disable rules
 
 You can disable specific rules per file, for a portion of a file, or for a single line. See the [ESLint rules](https://eslint.org/docs/latest/use/configure/rules#disable-rules) documentation. For example ...

circle.yml

@@ -25,6 +25,7 @@ workflows:
                 - 'globals'
                 - 'one-rule'
                 - 'recommended'
+                - 'typed'
           requires:
             - build-test-project
       - release:
@@ -46,7 +47,7 @@ jobs:
       - checkout
       - run:
           name: Install dependencies
-          command: npm ci
+          command: CYPRESS_INSTALL_BINARY=0 npm ci
       - run:
           name: Show ESLint version
           command: npx eslint --version
@@ -63,7 +64,7 @@ jobs:
       - checkout
       - run:
           name: Install dependencies
-          command: npm ci
+          command: CYPRESS_INSTALL_BINARY=0 npm ci
       - run:
           name: Install ESLint 9
           command: npm install eslint@9
@@ -80,7 +81,7 @@ jobs:
       - checkout
       - run:
           name: Install dependencies
-          command: npm ci
+          command: CYPRESS_INSTALL_BINARY=0 npm ci
       - run:
           name: Install ESLint 10
           command: npm install eslint@10
@@ -97,7 +98,7 @@ jobs:
       - checkout
       - run:
           name: Install dependencies
-          command: npm ci
+          command: CYPRESS_INSTALL_BINARY=0 npm ci
       - run:
           name: Build tarball
           command: npm pack
@@ -123,6 +124,10 @@ jobs:
         description: Configuration file
         default: 'recommended'
         type: string
+      typescript-eslint-version:
+        description: Version of typescript-eslint to use
+        default: 'latest'
+        type: string
     executor: docker-executor
     working_directory: ./test-project
     steps:
@@ -137,7 +142,7 @@ jobs:
       - run:
           name: Install dependencies
           command: |
-            npm install eslint@<< parameters.eslint-version>> ./eslint-plugin-cypress-$PLUGIN_VERSION.tgz -D
+            npm install eslint@<< parameters.eslint-version >> typescript-eslint@<< parameters.typescript-eslint-version >> ./eslint-plugin-cypress-$PLUGIN_VERSION.tgz -D
       - run:
           name: Display ESLint version
           command: |
@@ -154,7 +159,7 @@ jobs:
       - checkout
       - run:
           name: Install dependencies
-          command: npm ci
+          command: CYPRESS_INSTALL_BINARY=0 npm ci
       - run:
           name: Run semantic release
           command: npm run semantic-release

docs/rules/unsafe-to-chain-command.md

@@ -16,6 +16,18 @@
 
 <!-- end auto-generated rule options list -->
 
+## Typed Linting
+
+If [Typed Linting](../../README.md#typed-linting) is enabled, this rule also catches unsafe chaining even when the Cypress chain was started from a helper function.
+
+```js
+function getTodo() {
+  return cy.get('.todo')
+}
+
+getTodo().type('todo A{enter}').type('todo B{enter}')
+```
+
 ## Further Reading
 
 See [retry-ability guide](https://docs.cypress.io/app/core-concepts/retry-ability#Actions-should-be-at-the-end-of-chains-not-the-middle).

lib/rules/unsafe-to-chain-command.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const { basename } = require('path')
+const { isRootCypress } = require('./utils/is-root-cypress')
 
 const NAME = basename(__dirname)
 const DESCRIPTION = 'disallow actions within chains'
@@ -89,7 +90,7 @@ module.exports = {
     return {
       CallExpression(node) {
         if (
-          isRootCypress(node)
+          isRootCypress(node, context)
           && isActionUnsafeToChain(node, methods)
           && node.parent.type === 'MemberExpression'
         ) {
@@ -103,28 +104,6 @@ module.exports = {
   },
 }
 
-/**
- * @param {import('estree').Node} node
- * @returns {boolean}
- */
-const isRootCypress = (node) => {
-  if (
-    node.type !== 'CallExpression'
-    || node.callee.type !== 'MemberExpression'
-  ) {
-    return false
-  }
-
-  if (
-    node.callee.object.type === 'Identifier'
-    && node.callee.object.name === 'cy'
-  ) {
-    return true
-  }
-
-  return isRootCypress(node.callee.object)
-}
-
 /**
  * @param {import('estree').Node} node
  * @param {(string | RegExp)[]} additionalMethods

lib/rules/utils/is-root-cypress.js

@@ -0,0 +1,43 @@
+/**
+ * Checks if the root of a call expression originated from a 'cy' identifier.
+ * If type information are available, additionally checks the return type of helper functions.
+ *
+ * @param {import('estree').Node} node
+ * @param {import('eslint').Rule.RuleContext} context
+ * @returns {boolean}
+ */
+const isRootCypress = (node, context) => {
+  if (node.type !== 'CallExpression') {
+    return false
+  }
+
+  const calleeType = node.callee.type
+  if (calleeType === 'MemberExpression') {
+    if (node.callee.object.type === 'Identifier' && node.callee.object.name === 'cy') {
+      return true
+    }
+
+    return isRootCypress(node.callee.object, context)
+  }
+
+  if (calleeType === 'Identifier') {
+    const services = context?.sourceCode?.parserServices
+    if (services?.program && services.esTreeNodeToTSNodeMap) {
+      const checker = services.program.getTypeChecker()
+      const tsNode = services.esTreeNodeToTSNodeMap.get(node)
+      const signature = checker.getResolvedSignature(tsNode)
+
+      if (signature) {
+        const returnType = checker.getReturnTypeOfSignature(signature)
+        const symbol = returnType.getSymbol()
+        if (symbol) {
+          return checker.getFullyQualifiedName(symbol) === 'Cypress.Chainable'
+        }
+      }
+    }
+  }
+
+  return false
+}
+
+module.exports = { isRootCypress }