Start by installing Clojure and downloading Leiningen. Both should work just fine with Java 8 or 9. Clone this repository or download a zip archive with its contents. In the root directory of the project invoke the following command.

lein test

It will download 20ish MB worth of dependencies and run some tests.

Open project.clj in your favourite text editor or IDE to check if syntax highlighting works as expected.

Start the Clojure read-eval-print loop (also known as a REPL):

lein repl

and experiment with some Clojure expressions:

user=> (+ 0.1 0.2)
0.30000000000000004
user=> (for [x [2/10 0.2 4]] (+ x 1/10))
(3/10 0.30000000000000004 41/10)
user=> (.println System/out "Servus Weλt!")
Servus Weλt!
nil
user=> (sort (keys (System/getProperties)))
("awt.toolkit" "clojure.compile.path" ...)

You're good to go.

In the test directory you can find a lot of tests covering functionality we'll implement over the course of the workshop. Most of them are commented out; they will be ignored until the time we need them.

Take a look at test/shopping_summit/entities/cart_test.clj. Code preceded with a #_ is commented out. Remove a #_ sign to uncomment the expression follownig it.

Tests can be ran either in your terminal using

lein test

or in a REPL. To do it, start by reloading the test namespace of interest along with all namespaces it depends on.

(require 'shopping-summit.entities.cart-test :reload-all)
(clojure.test/test-ns 'shopping-summit.entities.cart-test)

Notice that testing in the REPL is much faster. We don't have to restart the JVM; we just dynamically recompile the code in a running Clojure environment.

Just ask me; I'm happy to help.

— Jan