feat: port rule no-unsafe-optional-chaining

[fansenze]

Summary

Port the no-unsafe-optional-chaining rule from ESLint to rslint.

Disallow use of optional chaining in contexts where the undefined value is not allowed

Related Links

• Tracking issue: [Tracking]: eslint core rules #223

• ESLint rule: https://eslint.org/docs/latest/rules/no-unsafe-optional-chaining

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[gemini-code-assist]

Summary of Changes

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This pull request introduces the no-unsafe-optional-chaining rule, a direct port from ESLint, into the rslint codebase. The primary goal of this rule is to enhance code robustness by identifying and preventing scenarios where optional chaining expressions might unexpectedly resolve to undefined and subsequently cause runtime TypeError exceptions or other undesirable behavior when used in contexts that do not tolerate undefined values. The implementation includes a detailed AST traversal to detect these patterns and offers a configurable option to also flag arithmetic operations that could result in NaN.

Highlights

• New Rule Implementation: The no-unsafe-optional-chaining rule has been ported from ESLint, aiming to prevent runtime TypeError issues arising from optional chaining expressions evaluating to undefined in incompatible contexts.
• Comprehensive Detection: The rule identifies unsafe optional chaining usage across various JavaScript constructs, including call expressions, property/element access, new expressions, destructuring assignments, for-of loops, in/instanceof operators, and class extends clauses.
• Configurable Arithmetic Check: An optional disallowArithmeticOperators setting allows the rule to also flag arithmetic operations on optional chaining results that could lead to NaN, providing enhanced safety.

Changelog

• internal/config/config.go
  • Imported the new no_unsafe_optional_chaining rule package.
  • Registered the no-unsafe-optional-chaining rule in the global rule registry.
• internal/rules/no_unsafe_optional_chaining/no_unsafe_optional_chaining.go
  • Added the core implementation of the no-unsafe-optional-chaining rule.
  • Defined two rule messages: unsafeOptionalChain for TypeError risks and unsafeArithmetic for NaN risks.
  • Implemented listeners for various AST node kinds (CallExpression, NewExpression, BinaryExpression, etc.) to detect unsafe optional chaining.
  • Included helper functions hasOptionalChain to recursively check for optional chains and isDestructuringPattern to identify destructuring assignments.
  • Added parseOptions to handle the disallowArithmeticOperators configuration.
• internal/rules/no_unsafe_optional_chaining/no_unsafe_optional_chaining.md
  • Created documentation for the no-unsafe-optional-chaining rule.
  • Provided detailed explanations of the rule's purpose and examples of both incorrect and correct code.
  • Documented the disallowArithmeticOperators option and its impact.
• internal/rules/no_unsafe_optional_chaining/no_unsafe_optional_chaining_test.go
  • Added comprehensive unit tests for the no-unsafe-optional-chaining rule.
  • Included a wide range of valid and invalid test cases covering different JavaScript constructs and the disallowArithmeticOperators option.
• packages/rslint-test-tools/rstest.config.mts
  • Updated the test configuration to include the new no-unsafe-optional-chaining.test.ts file for ESLint rules.
  • Added the new test file to the TypeScript ESLint rules section as well.
• packages/rslint-test-tools/tests/eslint/rules/snapshots/no-unsafe-optional-chaining.test.ts.snap
  • Generated snapshot tests for the no-unsafe-optional-chaining rule's invalid cases.
• packages/rslint-test-tools/tests/eslint/rules/no-unsafe-optional-chaining.test.ts
  • Added basic test cases for the no-unsafe-optional-chaining rule using RuleTester.

Activity

• The no-unsafe-optional-chaining rule has been implemented and integrated.
• Comprehensive test cases have been added to validate the rule's behavior, covering various scenarios and options.
• Documentation for the new rule, including its purpose, examples, and configuration options, has been created.

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[gemini-code-assist]

Code Review

This pull request ports the no-unsafe-optional-chaining rule from ESLint. The implementation is comprehensive, covering many edge cases, and includes good documentation and tests.

I've found a couple of issues:

• A correctness bug in the hasOptionalChain helper function which fails to correctly handle TSNonNullExpression.
• A redundant test file entry in the test runner configuration.

Details and suggestions are in the review comments. Overall, great work on porting this complex rule.