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deno

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A secure TypeScript runtime built on V8

  • Supports TypeScript 3.0.1 out of the box. Uses V8 6.9.297. 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.

  • Supports top-level await.

  • Aims to be browser compatible.

Status

Under development.

The prototype golang implementation is here. We are in the process of rewriting in C++/Rust to avoid future GC contention between Go and V8.

Progress towards first release is tracked here.

Roadmap is here. Also see this presentation.

Chat room.

Build instructions

To ensure reproducable 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.) .

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

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.