v2: Support Zod Mini; Remove dotenv & dotenv-expand; Improve Logging & Functionality

[noahtigner]

Changes

• Add support for Zod Mini
• Remove dotenv peer dependency; replacing with Node's new process.loadEnvFile
• Remove dotenv-expand peer dependency; replacing with streamlined version of its core functions
• Made the envPath parameter optional. If not provided, no file is read, and only process.env is validated
• Improve how field .meta is logged (title, description, and examples supported)
• Improve how schema is validated and field types are allowed/disallowed
• Refactor the codebase to improve readability and maintainability
• Update README.md with new instructions and examples
• Updated tests to cover new functionality and edge cases
• Add CHANGELOG.md

Example Output

[Copilot]

Pull request overview

This PR introduces version 2.0.0 of validate-env-vars with significant architectural changes and new functionality. The package now supports both Zod v4 Classic and Zod Mini, removes external dependencies (dotenv and dotenv-expand), and implements native environment variable loading and expansion using Node.js built-in features.

Key Changes:

• Adds Zod Mini support by migrating to zod/v4/core imports and updating type validation logic
• Replaces dotenv/dotenv-expand with custom implementation using Node's process.loadEnvFile() and custom expansion logic
• Makes envPath parameter optional, allowing validation of process.env without loading a file

Reviewed changes

Copilot reviewed 18 out of 21 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
package.json	Bumped to v2.0.0; removed dotenv dependencies; updated peer dependencies to support Zod ^4.0.0
package-lock.json	Removed dotenv and dotenv-expand packages from lock file
tsconfig.json	Changed target to "esnext"; added "local.ts" to exclusions
eslint.config.js	Streamlined ESLint configuration; separated source and test file linting rules
.gitignore	Added local.ts and .git to ignore list
src/schemaTypes.ts	Completely rewritten to use Zod v4 core types; removed custom env* helper functions
src/validateInput.ts	Added comprehensive field type validation for Zod v4; moved validation logic from index; added isValidFieldType function
src/logParseResults.ts	Enhanced logging with metadata support (title, description, examples); added helper functions for parsing metadata
src/loadEnvVars.ts	New file implementing custom env file loading with variable expansion (replaces dotenv/dotenv-expand)
src/index.ts	Simplified main entry point; refactored to use new validation and loading functions
src/constants.ts	Removed ALLOWED_TYPE_NAMES array; added HINT_SYMBOL constant
tests/validateInput.test.ts	Expanded test coverage for field type validation; added comprehensive test table
tests/schemaTypes.test.ts	File deleted (helper functions removed from main API)
tests/logParseResults.test.ts	Updated tests for new logging format; added tests for metadata parsing
tests/loadEnvVars.test.ts	New test file for env loading and expansion functionality
tests/jest.setup.ts	Added mock for process.loadEnvFile; improved test environment setup
tests/index.test.ts	Updated integration tests for new API; removed dotenv-specific tests
tests/compatibility.test.ts	New test file verifying Zod Classic and Zod Mini compatibility
tests/.env.test	Renamed variables with TEST_ prefix; added more test cases
README.md	Updated documentation with new usage examples and schema recipes; fixed typo in function name
CHANGELOG.md	New file documenting version history and changes

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