Added Test-cases InputValidator Plugin

[tasbi03]

Description

This pull request introduces comprehensive unit tests and configurations for the input-validator project, improving the test coverage, validating core functionality, and enhancing code quality and reliability.

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What change does this PR introduce?

Added Unit Tests:

• Core Functionality:

  • validateFile.test.ts: Tests various cases for file validation (valid, invalid, empty, and oversized files).
  • getValidator.test.ts: Ensures the getValidator utility retrieves correct validators or returns undefined for invalid cases.
  • getPromptStyles.test.ts: Validates style generation for different prompt types (error, success, etc.).
  • mergePluginConfig.test.ts: Ensures user configurations are merged properly with default plugin configurations.
  • useRcbPlugin.test.ts: Tests plugin behavior including text input, file upload validations, and event handling.

• Configuration Files:

  • jest.config.js: Configures Jest for testing.
  • setup.jest.js: Adds polyfills (e.g., structuredClone) and sets up the environment for consistent test execution.

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Closes issue #3

What is the proposed approach?

The PR covers:

1. Comprehensive Testing:
   • Tests edge cases for file and text validation logic.
   • Ensures utility functions (mergePluginConfig, getValidator, getPromptStyles) behave correctly under various configurations.
   • Validates plugin behavior including event listeners and style restoration.
2. Improved Code Coverage:
   • Focused on untested lines and branches to achieve near-complete coverage.
   • Adds tests for scenarios like null/undefined inputs, event listener behavior, and default configurations.
3. Environment Setup:
   • Configures Jest and introduces setup.jest.js to provide consistent polyfills for structuredClone and other necessary utilities.

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Checklist:

• Added unit tests for validateFile, getValidator, mergePluginConfig, getPromptStyles, and useRcbPlugin.
• Configured jest.config.js for comprehensive test runs.
• Introduced setup.jest.js for environment consistency.
• Verified test coverage and addressed untested lines or branches.

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Testing Summary:

This PR ensures:

• Core functionality and utility methods are validated against edge cases.
• Styles and plugin configurations are correctly managed.
• Event listeners in useRcbPlugin behave as expected for text inputs and file uploads.

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Feel free to review and suggest additional improvements or scenarios for coverage.

[tjtanjin]

Hey @tasbi03! Thanks for the PR, the test cases look great, though a couple of stuffs to cleanup:

• Lint errors need to be fixed
• Remove unnecessary packages in package file
• Add the coverage folder to gitignore (coverage files shouldn't be committed)