@typescript-eslint/prefer-includes

[ScriptedAlchemy]

Summary: Port @typescript-eslint/prefer-includes from ScriptedAlchemy#13.

Related Links:

• chore: small tweaks to add a few missing rules ScriptedAlchemy/rslint#13

Checklist:

• Tests updated
• Documentation updated (rule md)

[gemini-code-assist]

Summary of Changes

Hello @ScriptedAlchemy, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request integrates the @typescript-eslint/prefer-includes rule into the linter. This rule aims to enhance code readability and maintainability by promoting the use of the includes() method over less explicit indexOf comparisons or RegExp.prototype.test() calls. By standardizing these checks, the change helps developers write cleaner and more understandable JavaScript/TypeScript code.

Highlights

• New TypeScript ESLint Rule Added: Introduced the @typescript-eslint/prefer-includes rule, which encourages the use of Array.prototype.includes() or String.prototype.includes() for better readability and intent clarity.
• Improved Code Readability: The new rule identifies and provides auto-fixes for common patterns like indexOf(...) !== -1 or RegExp.prototype.test() that can be simplified using includes().
• Comprehensive Testing and Documentation: The rule comes with dedicated unit tests covering various scenarios and detailed Markdown documentation explaining its purpose, incorrect examples, and correct usage.

Changelog

• internal/config/config.go
  • Imported the new prefer_includes rule module.
  • Registered the @typescript-eslint/prefer-includes rule within the global rule registry.
• internal/plugins/typescript/rules/prefer_includes/prefer_includes.go
  • Added the core implementation for the prefer-includes rule.
  • Implemented logic to detect indexOf comparisons (e.g., !== -1, === -1) and RegExp.prototype.test() calls.
  • Included helper functions for parsing regular expressions, escaping strings, and checking node types.
  • Provided auto-fixing capabilities to transform identified patterns into includes() calls.
• internal/plugins/typescript/rules/prefer_includes/prefer_includes.md
  • Added documentation for the prefer-includes rule.
  • Provided examples of both incorrect and correct code usage for the rule.
• internal/plugins/typescript/rules/prefer_includes/prefer_includes_test.go
  • Added unit tests for the prefer-includes rule.
  • Included test cases for valid code that should not trigger the rule.
  • Provided test cases for invalid code, demonstrating how the rule identifies issues and applies auto-fixes.
• packages/rslint-test-tools/rstest.config.mts
  • Enabled the prefer-includes.test.ts file in the test configuration to ensure the new rule's tests are run.
• packages/rslint-test-tools/tests/typescript-eslint/rules/snapshots/prefer-includes.test.ts.snap
  • Added snapshot test results for the prefer-includes rule, capturing expected diagnostics and output for various invalid code scenarios.
• rslint.json
  • Added the @typescript-eslint/prefer-includes rule to the default configuration, initially setting its status to 'off'.

Activity

• The author has updated tests to cover the new rule's functionality.
• Documentation for the new rule has been updated (rule md).

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[gemini-code-assist]

Code Review

The pull request ports the @typescript-eslint/prefer-includes rule to the Go-based linter. The implementation correctly identifies indexOf comparisons and /regex/.test(str) calls that can be replaced with includes(). However, I identified a few critical issues in the auto-fix logic: specifically, incorrect range calculations when parentheses are present in indexOf checks, and an incorrect order of fix applications in the regex conversion logic. I also suggested adding a missing nil check for the type checker and improving numeric literal parsing to support non-decimal formats.

[Copilot]

Pull request overview

This pull request ports the @typescript-eslint/prefer-includes rule from the ScriptedAlchemy/rslint repository. The rule encourages the use of includes() method instead of indexOf() comparisons (like indexOf() !== -1), and also suggests using String#includes() instead of simple regex patterns with .test() when appropriate. This leads to more readable and expressive code.

Changes:

• Implemented the prefer-includes rule in Go with comprehensive type checking and auto-fix capabilities
• Added test coverage in both TypeScript and Go test files with multiple edge cases
• Enabled the rule in test configuration and registered it in the global rule registry

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
rslint.json	Added rule configuration (set to "off" by default)
packages/rslint-test-tools/tests/typescript-eslint/rules/prefer-includes.test.ts	Added valid and invalid test cases including edge cases for optional chaining, regex patterns, and type arrays
packages/rslint-test-tools/tests/typescript-eslint/rules/snapshots/prefer-includes.test.ts.snap	New snapshot file containing expected diagnostic outputs for all test cases
packages/rslint-test-tools/rstest.config.mts	Enabled the prefer-includes test file in test configuration
internal/plugins/typescript/rules/prefer_includes/prefer_includes_test.go	Go test implementation with key test cases
internal/plugins/typescript/rules/prefer_includes/prefer_includes.md	Documentation explaining the rule with examples
internal/plugins/typescript/rules/prefer_includes/prefer_includes.go	Core implementation with logic for detecting indexOf comparisons and regex patterns, including auto-fix generation
internal/config/config.go	Imported and registered the new rule in the global rule registry

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