fix(unbound-method): fix issue 1800

src/rules/__tests__/unbound-method.test.ts

@@ -49,6 +49,14 @@ const ConsoleClassAndVariableCode = dedent`
   const console = new Console();
 `;
 
+const ServiceClassAndMethodCode = dedent`
+  class Service {
+    method() {}
+  }
+
+  const service = new Service();
+`;
+
 const toThrowMatchers = [
   'toThrow',
   'toThrowError',
@@ -73,6 +81,13 @@ const validTestCases: string[] = [
   'expect(() => Promise.resolve().then(console.log)).not.toThrow();',
   ...toThrowMatchers.map(matcher => `expect(console.log).not.${matcher}();`),
   ...toThrowMatchers.map(matcher => `expect(console.log).${matcher}();`),
+  // https://github.com/jest-community/eslint-plugin-jest/issues/1800
+  ...[
+    'const parameter = jest.mocked(service.method).mock.calls[0][0];',
+    'const calls = jest.mocked(service.method).mock.calls;',
+    'const lastCall = jest.mocked(service.method).mock.calls[0];',
+    'const mockedMethod = jest.mocked(service.method); const parameter = mockedMethod.mock.calls[0][0];',
+  ].map(code => [ServiceClassAndMethodCode, code].join('\n')),
 ];
 
 const invalidTestCases: Array<TSESLint.InvalidTestCase<MessageIds, Options>> = [
@@ -235,6 +250,7 @@ const arith = {
 ${code}
   `;
 }
+
 function addContainsMethodsClassInvalid(
   code: string[],
 ): Array<TSESLint.InvalidTestCase<MessageIds, Options>> {

src/rules/unbound-method.ts

@@ -8,6 +8,7 @@ import {
   findTopMostCallExpression,
   getAccessorValue,
   isIdentifier,
+  isSupportedAccessor,
   parseJestFnCall,
 } from './utils';
 
@@ -73,9 +74,116 @@ export default createRule<Options, MessageIds>({
       return {};
     }
 
+    /**
+     * Checks if a MemberExpression is an argument to a `jest.mocked()` call.
+     * This handles cases like `jest.mocked(service.method)` where `service.method`
+     * should not be flagged as an unbound method.
+     */
+    const isArgumentToJestMocked = (
+      node: TSESTree.MemberExpression,
+    ): boolean => {
+      // Check if the immediate parent is a CallExpression
+      if (node.parent?.type !== AST_NODE_TYPES.CallExpression) {
+        return false;
+      }
+
+      const parentCall = node.parent;
+
+      // Check if this node is an argument to the call
+      if (!parentCall.arguments.some(arg => arg === node)) {
+        return false;
+      }
+
+      // Check if the call is jest.mocked() by examining the callee
+      if (
+        parentCall.callee.type === AST_NODE_TYPES.MemberExpression &&
+        isSupportedAccessor(parentCall.callee.object) &&
+        isSupportedAccessor(parentCall.callee.property)
+      ) {
+        const objectName = getAccessorValue(parentCall.callee.object);
+        const propertyName = getAccessorValue(parentCall.callee.property);
+
+        if (objectName === 'jest' && propertyName === 'mocked') {
+          return true;
+        }
+      }
+
+      // Also try using parseJestFnCall as a fallback
+      const jestFnCall = parseJestFnCall(
+        findTopMostCallExpression(parentCall),
+        context,
+      );
+
+      return (
+        jestFnCall?.type === 'jest' &&
+        jestFnCall.members.length >= 1 &&
+        isIdentifier(jestFnCall.members[0], 'mocked')
+      );
+    };
+
+    /**
+     * Checks if a MemberExpression is accessing `.mock` property on a
+     * `jest.mocked()` result. This handles cases like:
+     * - `jest.mocked(service.method).mock.calls[0][0]`
+     * - `jest.mocked(service.method).mock.calls`
+     */
+    const isAccessingMockProperty = (
+      node: TSESTree.MemberExpression,
+    ): boolean => {
+      // Check if we're accessing `.mock` property
+      if (!isSupportedAccessor(node.property)) {
+        return false;
+      }
+
+      const propertyName = getAccessorValue(node.property);
+
+      if (propertyName !== 'mock') {
+        return false;
+      }
+
+      // Traverse up the chain to find if the object is a jest.mocked() call
+      let current: TSESTree.Node = node.object;
+
+      while (current) {
+        if (current.type === AST_NODE_TYPES.CallExpression) {
+          const jestFnCall = parseJestFnCall(
+            findTopMostCallExpression(current),
+            context,
+          );
+
+          if (
+            jestFnCall?.type === 'jest' &&
+            jestFnCall.members.length >= 1 &&
+            isIdentifier(jestFnCall.members[0], 'mocked')
+          ) {
+            return true;
+          }
+        }
+
+        // Continue traversing up if the current node is part of a member chain
+        if (current.type === AST_NODE_TYPES.MemberExpression) {
+          current = current.object;
+        } else {
+          break;
+        }
+      }
+
+      return false;
+    };
+
     return {
       ...baseSelectors,
       MemberExpression(node: TSESTree.MemberExpression): void {
+        // Check if this MemberExpression is an argument to jest.mocked()
+        if (isArgumentToJestMocked(node)) {
+          return;
+        }
+
+        // Check if accessing .mock property on jest.mocked() result
+        if (isAccessingMockProperty(node)) {
+          return;
+        }
+
         if (node.parent?.type === AST_NODE_TYPES.CallExpression) {
           const jestFnCall = parseJestFnCall(
             findTopMostCallExpression(node.parent),