feat: port rule no-empty-character-class

[fansenze]

Summary

Port the no-empty-character-class rule from ESLint to rslint.

Disallow empty character classes in regular expressions

Related Links

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

• ESLint rule: https://eslint.org/docs/latest/rules/no-empty-character-class

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 a new linting rule, no-empty-character-class, to the rslint project. This rule enhances code quality by identifying and preventing the use of empty character classes in regular expressions, which are typically unintentional errors. The implementation includes the core rule logic, comprehensive documentation, and dedicated test cases to ensure its correctness and reliability.

Highlights

• New Linting Rule: Implemented the no-empty-character-class rule, ported from ESLint, to disallow empty character classes in regular expressions.
• Regex Validation: The new rule helps prevent common mistakes in regular expressions by flagging [] which do not match anything, improving code quality.

Changelog

• internal/config/config.go
  • Imported the no_empty_character_class rule.
  • Registered the no-empty-character-class rule in the global rule registry.
• internal/rules/no_empty_character_class/no_empty_character_class.go
  • Added the NoEmptyCharacterClassRule definition.
  • Implemented extractPattern to parse regex patterns from literal strings.
  • Implemented hasEmptyCharacterClass using a state machine to detect empty character classes.
• internal/rules/no_empty_character_class/no_empty_character_class.md
  • Created documentation for the no-empty-character-class rule, including rule details and examples of correct and incorrect code.
• internal/rules/no_empty_character_class/no_empty_character_class_test.go
  • Added Go-based unit tests for the NoEmptyCharacterClassRule, covering valid and invalid regex patterns.
• packages/rslint-test-tools/rstest.config.mts
  • Updated the test configuration to include the new no-empty-character-class.test.ts file.
• packages/rslint-test-tools/tests/eslint/rules/snapshots/no-empty-character-class.test.ts.snap
  • Added snapshot test results for the no-empty-character-class rule's invalid cases.
• packages/rslint-test-tools/tests/eslint/rules/no-empty-character-class.test.ts
  • Created a JavaScript-based rule tester file with valid and invalid test cases for the new rule.

Activity

• The author has marked the tests and documentation as updated/not required in the PR checklist.
• No other review comments or activity were found in the provided context.

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[gemini-code-assist]

Code Review

The pull request successfully ports the no-empty-character-class rule from ESLint to rslint. The core logic for detecting empty character classes in regular expression literals (/pattern/) appears correct and handles escaped characters and negated classes ([^]) appropriately. The documentation and test files have been added and configured correctly. However, a significant functional gap exists as the rule currently does not process regular expressions created via new RegExp("pattern"), which is a common pattern in JavaScript and is covered by the original ESLint rule.