Contributing

Fresh is organized as a monorepo with multiple packages:

• packages/fresh/ - Core Fresh framework (@fresh/core)
• packages/plugin-vite/ - Vite integration plugin (@fresh/plugin-vite)
• packages/plugin-tailwindcss/ - Tailwind CSS v4 plugin
• packages/plugin-tailwindcss-v3/ - Tailwind CSS v3 plugin
• packages/init/ - Project scaffolding tool
• packages/update/ - Fresh update utilities
• www/ - Documentation website (fresh.deno.dev)

Getting Started

Prerequisites: Deno (latest version) and Git.

git clone https://github.com/denoland/fresh.git
cd fresh
deno task ok

deno task ok runs formatting, linting, type checking, and the full test suite. Run it before submitting any pull request.

The repository uses Deno workspaces so all packages in packages/ are automatically available to each other using their published names (@fresh/core, @fresh/plugin-vite, etc.).

Development

The www/ directory and the Vite plugin demo both use local Fresh packages, making them good integration tests:

deno task www           # docs site dev server
deno task build-www     # docs site production build

deno task demo          # vite demo dev server
deno task demo:build    # vite demo production build
deno task demo:start    # serve vite demo production build

Testing in External Projects

To use your local Fresh checkout in a separate project, add links to the project's deno.json:

{
  "imports": {
    "@fresh/core": "jsr:@fresh/core@^2.0.0",
    "@fresh/plugin-vite": "jsr:@fresh/plugin-vite@^1.0.0"
  },
  "links": [
    "../path/to/fresh/packages/fresh",
    "../path/to/fresh/packages/plugin-vite"
  ]
}

This overrides the JSR packages with your local versions. Changes are reflected immediately without rebuilding.

Testing

# All tests (parallel)
deno task test

# A specific test file
deno test -A packages/fresh/src/app_test.ts

# Filter by test name
deno test -A --filter "test name pattern"

# Update snapshots after intentional output changes
deno test -A --update-snapshots path/to/test.ts

Tests use @std/expect for assertions, follow the *_test.ts naming convention, and require the -A flag. Snapshot tests are stored in __snapshots__/ directories.

Some tests may fail locally but pass in CI (Could not find server address, Text file busy (os error 26)) - these can be safely ignored.

Pull Requests

• Run deno task ok before submitting to catch formatting, lint, and type errors early
• Keep PRs focused - one feature or fix per PR
• Add or update tests for any behavior changes
• Follow existing code style - the repository uses deno fmt for formatting and deno lint for linting