Convert project to TypeScript

[Copilot]

This PR converts the entire project from JavaScript to TypeScript while maintaining 100% backward compatibility and preserving all existing behavior.

Changes

TypeScript Configuration

• Added tsconfig.json configured for CommonJS output targeting ES2020
• Added jest.config.js for TypeScript test support using ts-jest
• Updated ESLint configuration to support TypeScript parsing with @typescript-eslint plugins

Source Code Conversion

All source files have been converted to TypeScript:

• index.js → index.ts
• create-or-update-files.js → create-or-update-files.ts
• create-or-update-files.test.js → create-or-update-files.test.ts

All types are properly defined using Octokit's type system:

• Used Octokit type from @octokit/rest for the octokit parameter
• Used RestEndpointMethodTypes from @octokit/plugin-rest-endpoint-methods for method parameters and return types
• Defined proper interfaces for Options, Change, FileChange, and CommitResult
• All function signatures have explicit types from the Octokit API
• File mode and type properties are restricted to valid literal types

Package Configuration

Updated package.json:

• Main entry point: index.js → dist/index.js
• Added types field pointing to dist/index.d.ts for TypeScript consumers
• Added build scripts: build, prepare
• Updated lint and test scripts for TypeScript files

Dependencies

Added TypeScript-related dev dependencies:

• typescript - TypeScript compiler
• @types/jest, @types/node - Type definitions
• @typescript-eslint/eslint-plugin, @typescript-eslint/parser - ESLint TypeScript support
• ts-jest - Jest TypeScript preprocessor

Build Output

The project now builds to the dist/ directory containing:

• Compiled JavaScript (CommonJS)
• Type definitions (.d.ts)
• Source maps

The .gitignore has been updated to exclude build artifacts from version control.

Testing

✅ All 28 existing tests pass without modification
✅ Linting passes with no errors
✅ Build succeeds and generates correct output
✅ Plugin loads correctly from built code
✅ No security vulnerabilities detected

Backward Compatibility

This conversion maintains 100% backward compatibility:

• No changes to public API or behavior
• Compiled output is functionally identical to original JavaScript
• All existing consumers will continue to work without changes
• TypeScript consumers now get proper type definitions with full type safety

Migration Path

For consumers of this package:

• JavaScript users: No changes required, everything works as before
• TypeScript users: Type definitions are now available automatically via the types field in package.json with full type safety using Octokit's type system

Fixes #127

Original prompt

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This section details on the original issue you should resolve

<issue_title>Convert project to Typescript</issue_title>
<issue_description>Convert the project to Typescript without changing any behaviour. All existing tests must continue to pass</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #127

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[mheap]

@copilot Do not use any. Research which type to use. You can use types from Octokit directly if needed

[Copilot]

@copilot Do not use any. Research which type to use. You can use types from Octokit directly if needed

Replaced all any types with proper types from Octokit:

• Used Octokit type from @octokit/rest for the octokit parameter
• Used RestEndpointMethodTypes from @octokit/plugin-rest-endpoint-methods for method parameters and return types
• Defined proper interfaces for Options, Change, FileChange, and CommitResult
• All function signatures now have explicit types from the Octokit API

Commit: Updated in the latest commit