Posted on May 30, 2020

A better way to launch Deno with many command options

Deno, like many other compiler or script runners, can require a complex list of options to type in at the command line. I wanted an easier to way run Deno.

I created Zap as a way to solve that problem (currently MacOS but I'm currently updating it to run on Windows -- stay tuned). Zap uses a configuration file to store all the options and launches Deno using them.

It also loads .env files to load environment variables.

To install, type:

$ deno install -Af -n zap https://deno.land/x/gh:deno-nonstd:zap/app.ts

NOTE: If you haven't previously added /.deno/bin to your $PATH variable, then you will need to or Deno won't run the utility. It seems to be different for everyone (even on OSX) but this worked for me:

$ echo '/User/<name>/.deno/bin' | sudo tee /etc/paths.d/deno

Then any NEW command window or app started will see the path.

To use, Instead of typing:

$ deno run --allow-env --allow-net=google.com,deno.land --allow-read unstable app.ts

You can provide a config file like this (default name is launch.yaml):

deno: run: main: app.ts dotenv: main.env security: allow-env: true allow-read: true allow-net: - google.com - deno.land install: main: app.ts security: allow-env: true options: force: true name: sampleApp

Notice there is a run and install. Each is called a profile. You can configure each of them separately.

You can launch your app now like any of the below:

$ zap run

$ zap install

And Zap will do the rest.

To initialize with a default profile, type:

$ zap init launch.yaml

And it'll put a default file there named launch.yaml. launch is the default name that Zap looks for, so you won't need to provide it when running.

If you want to initialize a .dotenv file, just type:

$ zap init dev.env

And it'll create a file with that name. You can tell zap to load from the .dotenv file with an option named dotenv like this:

deno: run: main: app.ts dotenv: main.env ...

You can configure and use any of the valid Deno subcommands. The format for a launch file looks like this:

File Name: launch.yaml

deno: <command> # run, install, cache, test, fmt, etc main: <starting file name> dotenv: <file name> # if desired security: allow-all: true # true for on, empty for false allow-net: true # true for blanket enable OR... allow-net: - google.com - deno.land. # to whitelist  ... # any valid security option (--allow-...) options: ... any valid option, using same rules as above