feat(to-have-length): support optional chaining operator

Author: hekystyle

src/rules/__tests__/prefer-to-have-length.test.ts

@@ -5,7 +5,7 @@ import { espreeParser } from './test-utils';
 const ruleTester = new TSESLint.RuleTester({
   parser: espreeParser,
   parserOptions: {
-    ecmaVersion: 2015,
+    ecmaVersion: 2020,
   },
 });
 
@@ -16,6 +16,7 @@ ruleTester.run('prefer-to-have-length', rule, {
     'expect(files).toHaveLength(1);',
     "expect(files.name).toBe('file');",
     "expect(files[`name`]).toBe('file');",
+    'expect(users[0]?.permissions).toHaveLength(1);',
     'expect(result).toBe(true);',
     `expect(user.getUserName(5)).resolves.toEqual('Paul')`,
     `expect(user.getUserName(5)).rejects.toEqual('Paul')`,
@@ -74,5 +75,10 @@ ruleTester.run('prefer-to-have-length', rule, {
       output: 'expect(files).not.toHaveLength(1);',
       errors: [{ messageId: 'useToHaveLength', column: 26, line: 1 }],
     },
+    {
+      code: 'expect(users[0]?.permissions?.length).toBe(1);',
+      output: 'expect(users[0]?.permissions).toHaveLength(1);',
+      errors: [{ messageId: 'useToHaveLength', column: 39, line: 1 }],
+    },
   ],
 });

src/rules/prefer-to-have-length.ts

@@ -1,4 +1,4 @@
-import { AST_NODE_TYPES } from '@typescript-eslint/utils';
+import { AST_NODE_TYPES, TSESTree } from '@typescript-eslint/utils';
 import {
   EqualityMatcher,
   createRule,
@@ -7,6 +7,13 @@ import {
   parseJestFnCall,
 } from './utils';
 
+const followOptionalChaining = (
+  expression: TSESTree.CallExpressionArgument,
+): TSESTree.CallExpressionArgument =>
+  expression.type === AST_NODE_TYPES.ChainExpression
+    ? followOptionalChaining(expression.expression)
+    : expression;
+
 export default createRule({
   name: __filename,
   meta: {
@@ -41,10 +48,15 @@ export default createRule({
         const [argument] = expect.arguments;
         const { matcher } = jestFnCall;
 
+        if (!EqualityMatcher.hasOwnProperty(getAccessorValue(matcher))) {
+          return;
+        }
+
+        const expression = followOptionalChaining(argument);
+
         if (
-          !EqualityMatcher.hasOwnProperty(getAccessorValue(matcher)) ||
-          argument?.type !== AST_NODE_TYPES.MemberExpression ||
-          !isSupportedAccessor(argument.property, 'length')
+          expression?.type !== AST_NODE_TYPES.MemberExpression ||
+          !isSupportedAccessor(expression.property, 'length')
         ) {
           return;
         }
@@ -54,7 +66,10 @@ export default createRule({
             return [
               // remove the "length" property accessor
               fixer.removeRange([
-                argument.property.range[0] - 1,
+                expression.property.range[0] -
+                  (expression.parent?.type === AST_NODE_TYPES.ChainExpression
+                    ? 2
+                    : 1),
                 argument.range[1],
               ]),
               // replace the current matcher with "toHaveLength"