deno

Linux & Mac Windows

A secure TypeScript runtime built on V8

  • Supports TypeScript 3.0 out of the box. Uses V8 7.0. That is, it’s very modern JavaScript.

  • No package.json. No npm. Not explicitly compatible with Node.

  • Imports reference source code URLs only.

    import { test } from "https://unpkg.com/deno_testing@0.0.5/testing.ts";
import { log } from "./util.ts";

    Remote code is fetched and cached on first execution, and never updated until the code is run with the --reload flag. (So, this will still work on an airplane. See ~/.deno/src for details on the cache.)

  • File system and network access can be controlled in order to run sandboxed code. Defaults to read-only file system access and no network access. Access between V8 (unprivileged) and Rust (privileged) is only done via serialized messages defined in this flatbuffer. This makes it easy to audit. To enable write access explicitly use --allow-write and --allow-net for network access.

  • Single executable:

    > ls -lh out/release/deno
-rwxr-xr-x  1 rld  staff    48M Aug  2 13:24 out/release/deno
> otool -L out/release/deno
out/release/deno:
  /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.50.4)
  /usr/lib/libresolv.9.dylib (compatibility version 1.0.0, current version 1.0.0)
  /System/Library/Frameworks/Security.framework/Versions/A/Security (compatibility version 1.0.0, current version 58286.51.6)
  /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 400.9.0)
>

  • Always dies on uncaught errors.

  • Aims to support top-level await.

  • Aims to be browser compatible.

Install

With Python:

curl -sSf https://raw.githubusercontent.com/denoland/deno_install/master/install.py | python

With PowerShell:

iex (iwr https://raw.githubusercontent.com/denoland/deno_install/master/install.ps1)

Note: Depending on your security settings, you may have to run Set-ExecutionPolicy RemoteSigned -Scope CurrentUser first to allow downloaded scripts to be executed.

Try it:

> deno http://deno.land/thumb.ts

See also deno_install.

Status

Under development.

We make binary releases here.

Progress towards future releases is tracked here.

Roadmap is here. Also see this presentation.

Benchmarks

Chat room.

Build instructions

To ensure reproducible builds, Deno has most of its dependencies in a git submodule. However, you need to install separately:

  1. Rust
  2. Node
  3. Python 2. Not 3.
  4. ccache (Optional but helpful for speeding up rebuilds of V8.).
  5. Extra steps for Windows users:
    1. Add python.exe to PATH. E.g. set PATH=%PATH%;C:\Python27\python.exe
    2. Get VS Community 2017, make sure to select the option to install C++ tools and the Windows SDK
    3. Enable Debugging Tools for Windows, Goto Control Panel -> Windows 10 SDK -> Right-Click -> Change -> Change -> Check Debugging Tools for Windows -> Change -> Finish

To build:

# Fetch deps.
git clone --recurse-submodules https://github.com/denoland/deno.git
cd deno
./tools/setup.py

# Build.
./tools/build.py

# Run.
./out/debug/deno tests/002_hello.ts

# Test.
./tools/test.py

# Format code.
./tools/format.py

Before running ./tools/format.py, make sure you have yapf installed for the current Python and rustfmt for Rust. They can be installed by:

pip install yapf
rustup component add rustfmt-preview

Other useful commands:

# Call ninja manually.
./third_party/depot_tools/ninja -C out/debug
# Build a release binary.
DENO_BUILD_MODE=release ./tools/build.py :deno
# List executable targets.
./third_party/depot_tools/gn ls out/debug //:* --as=output --type=executable
# List build configuation.
./third_party/depot_tools/gn args out/debug/ --list
# Edit build configuration.
./third_party/depot_tools/gn args out/debug/
# Describe a target.
./third_party/depot_tools/gn desc out/debug/ :deno
./third_party/depot_tools/gn help

Env vars: DENO_BUILD_MODE, DENO_BUILD_PATH, DENO_BUILD_ARGS.

Contributing

  1. Fork this repository and create your branch from master.
  2. Make your change.
  3. Ensure ./tools/test.py passes.
  4. Format your code with ./tools/format.py.
  5. Make sure ./tools/lint.py passes.
  6. Send a pull request.
  7. Sign the CLA, if you haven’t already.