mcjs

Minecraft commands generated with JavaScript

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MCJS Documentation

MCJS is both a compiler and a file format:

• .mcjs files are .mcfunction files wrapped with JavaScript.
• The compiler is used from the terminal to generate .mcfunction files from .mcjs.

Installation

MCJS requires Node.js to function, which can be downloaded from here. Once installed, open a terminal and run:

npm install -g @open-mapmaking/mcjs

Command line interface

MCJS is accessible from the terminal.

Compilation

Compile a single file from .mcjs to .mcfunction:

mcjs filename.mcjs

Will generate filename.mcfunction.

Pass a folder to compile each .mcjs files it contains to .mcfunction:

cd path/to/datapack
mcjs ./

Watch

With the watch command, each .mcjs file save will trigger a recompilation:

mcjs watch filename.mcjs

It also works with a whole folder:

cd path/to/datapack
mcjs watch ./

Reference

.mcjs files contain regular JavaScript and, when compiled, are executed just like .js files. They have access to the whole JavaScript syntax and to MCJS specific objects, which are specified here.

The cmd function

At compilation, it is the cmd function that outputs commands in the resulting .mcfunction file. It takes a string as a parameter:

cmd('say Hello world!')
cmd('summon creeper ~ ~ ~')

Will result to a .mcfunction file containing:

say Hello world!
summon creeper ~ ~ ~

cmd is also a template tag, which can write multiple commands at once. It also enable access to ${expression} placeholders:

let entity = 'creeper'
cmd`
summon ${entity} ~ ~ ~
execute as @e[type=${entity}] run say hello
`

Will result to:

summon creeper ~ ~ ~
execute as @e[type=creeper] run say hello