feat: port rule no-unreachable

[fansenze]

Summary

Port the no-unreachable rule from ESLint to rslint.

Disallow unreachable code after return, throw, continue, and break statements

Related Links

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

• ESLint rule: https://eslint.org/docs/latest/rules/no-unreachable

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 static analysis rule, no-unreachable, to the rslint project. This rule aims to improve code quality by identifying and flagging code segments that are logically impossible to reach during execution. By preventing dead code, it helps developers maintain cleaner, more efficient, and less error-prone codebases, aligning rslint's capabilities with established best practices from ESLint.

Highlights

• New Linting Rule: Introduced the no-unreachable rule, ported from ESLint, to detect and disallow code that cannot be executed after terminal statements.
• Unreachable Code Detection: The rule identifies code following return, throw, break, and continue statements as unreachable.
• Hoisting and Exceptions: Implemented logic to correctly account for JavaScript hoisting, allowing function declarations and var declarations without initializers after terminal statements, while reporting let, const, and class declarations.
• Comprehensive Testing: Added extensive unit tests and ESLint-style test cases, including snapshot tests, to ensure the rule's accuracy and coverage.

Changelog

• internal/config/config.go
  • Imported and registered the new no-unreachable rule within the rslint configuration.
• internal/rules/no_unreachable/no_unreachable.go
  • Implemented the core logic for the no-unreachable rule, including functions to identify terminal statements and handle hoisted or empty statements.
• internal/rules/no_unreachable/no_unreachable.md
  • Added detailed documentation for the no-unreachable rule, including examples of correct and incorrect code.
• internal/rules/no_unreachable/no_unreachable_test.go
  • Added comprehensive Go unit tests for the no-unreachable rule, covering various valid and invalid code scenarios.
• packages/rslint-test-tools/rstest.config.mts
  • Updated the test configuration to include the new no-unreachable rule's test files.
• packages/rslint-test-tools/tests/eslint/rules/snapshots/no-unreachable.test.ts.snap
  • Generated snapshot test results for the no-unreachable rule's ESLint-style tests.
• packages/rslint-test-tools/tests/eslint/rules/no-unreachable.test.ts
  • Added ESLint-style test cases for the no-unreachable rule.

Activity

• The author, fansenze, created the pull request to port the no-unreachable rule.
• The author marked the tests and documentation as updated/not required in the checklist.

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[gemini-code-assist]

Code Review

This pull request ports the no-unreachable rule from ESLint to rslint. The implementation is solid, with good test coverage and documentation. I've found a couple of areas for improvement: one is to refactor some duplicated code in the rule implementation for better maintainability, and the other is to remove a redundant test file entry in the configuration to avoid running tests twice. Overall, great work on porting the rule.