# Clojure projects

Clojure CLI projects use a [`deps.edn` file](/clojure/clojure-cli/#configure-clojure-cli) to specifies source paths and libraries required for the project to run.   

alias are defined in the  `deps.edn` file to support development tasks, providing additional libraries, paths and tools. 

!!! HINT "Generate a project from a template"
    [Create a project from a template](templates/) for a consistent project structure and include commonly used libraries.

    [Practicalli Project Templates](templates/practicalli/) create production grade projects providing a detailed starting point with configuration files for building and deploying the project.


## Create minimal project

Create a `deps.edn` file containing `{}` in the root of a directory for a minimal configuration.

Create a `src` directory as the root of the source code, and `test` directory to contain unit test code.

??? TIP "Linux command to create a minimal clojure project"
    Run these Linux commands in the root of a directory to create a minimal Clojure project structure.
    ```shell
    touch deps.edn && echo '{}' > deps.edn && mkdir src test
    ```

The project can now be run with a REPL via a [terminal UI](../repl/) or [Clojure aware Editor](/clojure/clojure-editors/).


??? TIP "Migrate project to Clojure CLI"
    [Guide to Migrating a project to Clojure CLI](migrate-project.md){target=_blank .md-button}


## Project Structure

The essence of most Clojure CLI projects contains the following files and directories.

| path         | purpose                                                           |
|--------------|-------------------------------------------------------------------|
| deps.edn     | core project configuration, paths, dependencies and aliases       |
| build.clj    | build specific configuration, create jars and uberjars            |
| src          | root directory of Clojure source files                            |
| test         | root directory for Clojure test source files                      |
| README.md    | Description of the project and how to develop / maintain it       |
| CHANGELOG.md | Meaningful history of changes to the project organised by release |
| .git         | Local git repository and configuration                            |
| .gitignore   | Git ignore patterns for the project                               |


!!! EXAMPLE "Example deps.edn configuration file"
    ```clojure
    {:paths
     ["src" "resources"]

     :deps
     {org.clojure/clojure    {:mvn/version "1.11.1"}}
      http-kit/http-kit      {:mvn/version "2.6.0"}  
      metosin/reitit         {:mvn/version "0.5.13"}
      com.brunobonacci/mulog {:mvn/version "0.9.0"}

     :aliases
     {;; Clojure.main execution of application
      :run/service
      {:main-opts ["-m" "practicalli.donuts.service"]}

      ;; Clojure.exec execution of specified function
      :run/greet
      {:exec-fn   practicalli.donuts.service/greet
       :exec-args {:name "Clojure"}}

      ;; Add libraries and paths to support additional test tools
      :test/env
      {}

      ;; Test runner - local and CI
      ;; call with :watch? true to start file watcher and re-run tests on saved changes
      :test/run
      {:extra-paths ["test"]
       :extra-deps  {lambdaisland/kaocha {:mvn/version "1.85.1342"}}
       :main-opts   ["-m" "kaocha.runner"]
       :exec-fn     kaocha.runner/exec-fn
       :exec-args   {:randomize? false
                     :fail-fast? true}}

      ;; tools.build `build.clj` built script
      :build
      {:replace-paths ["."]
       :replace-deps  {io.github.clojure/tools.build
                       {:git/tag "v0.9.4" :git/sha "76b78fe"}}
       :ns-default    build}}}
    ```