Create build file

As ClojureScript is a Clojure library, a simple build tool can be easily scripted in a few lines of Clojure.

Create a file called build.clj in the cljs_compiler directory and add the following Clojure code:

(require 'cljs.build.api)

(cljs.build.api/build "src" {:output-to "out/main.js"})

Hint In order to compile the ClojureScript code, we use the build function from the library cljs.build.api. To access the functions of this library we use the require function. This is similar to import or include in other languages.

The cljs.build.api/build function takes two arguments: the directory to compile and a map of options. In our code we include the option :output-to that specifies where to write the JavaScript.