Velociraptor

An npm-style script runner for Deno

Motivation

Mainly because Deno cli commands can easily become very long and difficult to remember. Also, npm scripts are cool 😎

Install

$ deno install --allow-read --allow-env --allow-run -n vr https://deno.land/x/velociraptor/cli.ts

$ deno install ... https://deno.land/x/velociraptor@<version>/cli.ts
                                                    ^^^^^^^^^

$ deno install --allow-read --allow-env --allow-run -n vr https://deno.land/x/velociraptor@v1.0.0-beta.4/cli.ts

Usage

$ vr [SCRIPT] [ADDITIONAL ARGS]...
# or
$ vr run <SCRIPT> [ADDITIONAL ARGS]...

SCRIPT
The identifier of the script to run.

ADDITIONAL ARGS
Any other argument, passed to the script. Unlike npm run, the -- separator is not needed.

Run vr without arguments to see a list of available scripts.

Run vr --help for more guidance.

Project status

👨‍💻 WIP: until the Deno std library is stable there may be breaking changes here, use carefully and feel free to open an issue if you found a bug.

Script files

To define scripts, create a file called scripts.yaml or velociraptor.yaml in your project folder.

# scripts.yaml
scripts:
  start: deno run --allow-net server.ts
  test: deno test --allow-net server_test.ts

.json is supported as well:

// scripts.json
{
  "scripts": {
    "start": "deno run --allow-net server.ts",
    "test": "deno test --allow-net server_test.ts"
  }
}

Basic scripts

In its simplest form, the scripts property behaves like in package.json: the keys are script names and the values are the command strings.

Compact deno run

When a command starts with a .ts file, deno run is automatically prepended:

scripts:
  start: server.ts # Equivalent to `deno run server.ts`

More script options

Scripts can also be objects:

scripts:
  start:
    desc: Runs the server
    cmd: deno run --allow-net server.ts

In this case the command(s) are specified in the cmd property. Use the desc property to provide a description of what the script does, it’ll be shown in the list of available scripts (when running vr without arguments).

👇 The following properties can be specified both in script objects and at top-level, in which case they are applied to all the scripts defined in the file. Deno options are effectively only applied to deno commands that accept them.

Environment variables

Environment variables can be specified in the env mapping.

# Env vars specified here are sent to
# all the scripts
env:
  PORT: 8081

scripts:
  start:
    cmd: deno run --allow-net server.ts
    env: # and these are script-specific
      PORT: 8082

Permissions

Deno permissions can be specified using allow.

# `allow` can be a list of boolean flags
allow:
  - net
  - read

scripts:
  start:
    cmd: server.ts
    allow: # or a map
      net: 127.0.0.1

Tsconfig

To specify a tsconfig, set the tsconfig property.

scripts:
  start:
    cmd: server.ts
    tsconfig: tsconfig.json

Import maps

Import maps are speficied in imap.

scripts:
  start:
    cmd: deno run --unstable server.ts
    imap: importmap.json

🧪 Import maps are currently marked as unstable so the --unstable flag must be provided.

Inspect

inspect and inspectBrk correspond to the --inspect and --inspect-brk options.

scripts:
  start:
    cmd: server.ts
    inspect: 127.0.0.1:9229

Lockfile

The lock property sets the namesake deno option.

scripts:
  start:
    cmd: server.ts
    lock: lock.json

⚠️ Setting this option doesn’t create a lock file: you will have to create/update it by passing the --lock-write option manually to your script at the appropriate time. More info here.

Log

The log property corresponds to deno’s --log-level. The allowed values are debug and info.

scripts:
  start:
    cmd: server.ts
    log: debug

Cert

Specify a PEM certificate for http client in cert.

scripts:
  start:
    cmd: server.ts
    cert: certificate.pem

V8 flags

V8 flags can be specified like permissions under the v8Flags property.

v8Flags:
  - expose-gc
  - async-stack-trace

scripts:
  start:
    cmd: server.ts
    v8Flags:
      logfile: v8.log

Multiple commands

If the script value is an array of commands, the commands are executed serially.

scripts:
  start:
    - deno run one.ts
    - deno run two.ts
  test: # Compound scripts can contain script objects as well
    - deno test test_one.ts
    - cmd: deno test test_two.ts
      tsconfig: tsconfig.json

To execute commands in parallel, list them in the pll property of an object.

scripts:
  start:
    pll:
      - deno run one.ts
      - deno run two.ts

Parallel and serial scripts can be combined as well.

scripts:
  start:
    - pll:
        - deno run one.ts
        - deno run two.ts
    - deno run three.ts

Multiple commands specified in this way are executed separately. If you need to use pipes/redirections you can use your shell’s syntax:

scripts:
  start: cat file.ts | deno

Script file model

See ScriptConfiguration for a detailed description of the structure of script files.

Shell scripting

Like in npm scripts, vr commands are executed inside a shell. The shell is determined by the SHELL env variable on Unix-like systems and by ComSpec on Windows, with respectively sh and cmd.exe as fallback values. To customize the shell without changing you default shell env variables you can use the VR_SHELL variable (a full path is requried).

The shell requirements are pretty much the same as node’s.

Current working directory

Velociraptor searches for script files up the folder tree starting from the directory where the vr command was launched. Scripts are run from the directory where the script file is, independently of the initial location.

Shell completions

To enable shell tab-completion for Velociraptor commands, add the following line to your ~/.zshrc

source <(vr completions zsh)

Trigger the autocomplete on vr/vr run to get the available scripts as suggestions.

Bash completions are not supported yet, but will be added.

Known limitations

Commands with quotes are currently unusable when the shell is cmd.exe due to the way Rust’s std::Command (used by Deno.run()) escapes cli arguments (see here).
As a workaround you can tell Velociraptor to use PowerShell instead of cmd (see Shell scripting) or run your scripts in the Windows Subsystem for Linux.

Upcoming features

• Self-update: run vr updgrade to install the latest version.
• Scripts exporting: run vr export to save your scripts as shell scripts to avoid having to install vr in your production environment.
• Husky style git hooks: use the hook property to link a script to a git hook.

Contributing

Feedback and PRs are welcome! Just make sure to run deno fmt before committing ✨

License

This project is licensed under the MIT License. See LICENSE for details.