diff --git a/.gitignore b/.gitignore
index 5e67719..fc6713d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,4 +14,5 @@ pom.xml.asc
 .cpcache/
 .shadow-cljs/
 node_modules/
-/public/js
\ No newline at end of file
+/public/js
+/out
\ No newline at end of file
diff --git a/README.md b/README.md
index c7d7812..0870522 100644
--- a/README.md
+++ b/README.md
@@ -4,9 +4,12 @@ Embeds mastodon timline into a html page. Uses JS, no intermediate server requir
 
 # Setup
 
-sudo npm i -g npx
+sudo npm install -g npx
+sudo npm install -g source-map-support
+sudo npm install -g shadow-cljs
 
 # Development
 
-npx shadow-cljs node-repl
-npx shadow-cljs watch frontend
\ No newline at end of file
+shadow-cljs node-repl
+shadow-cljs watch frontend
+shadow-cljs compile test
\ No newline at end of file
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..869e401
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,30 @@
+{
+  "name": "dda-masto-embed",
+  "version": "0.0.1",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "buffer-from": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.1.tgz",
+      "integrity": "sha512-MQcXEUbCKtEo7bhqEs6560Hyd4XaovZlO/k9V3hjVUF/zwW7KBVdSK4gIt/bzwS9MbR5qob+F5jusZsb0YQK2A==",
+      "dev": true
+    },
+    "source-map": {
+      "version": "0.6.1",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+      "dev": true
+    },
+    "source-map-support": {
+      "version": "0.5.19",
+      "resolved": "https://registry.npmjs.org/source-map-support/-/source-map-support-0.5.19.tgz",
+      "integrity": "sha512-Wonm7zOCIJzBGQdB+thsPar0kYuCIzYvxZwlBa87yi/Mdjv7Tip2cyVbLj5o0cFPN4EVkuTwb3GDDyUx2DGnGw==",
+      "dev": true,
+      "requires": {
+        "buffer-from": "^1.0.0",
+        "source-map": "^0.6.0"
+      }
+    }
+  }
+}
diff --git a/package.json b/package.json
index ccc67e9..ad0be88 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,8 @@
   "version": "0.0.1",
   "private": true,
   "devDependencies": {
-    "shadow-cljs": "2.8.100"
+    "shadow-cljs": "2.8.100",
+    "source-map-support": "^0.5.19"
   },
   "dependencies": {}
 }
diff --git a/shadow-cljs.edn b/shadow-cljs.edn
index d643eb9..19e4f0f 100644
--- a/shadow-cljs.edn
+++ b/shadow-cljs.edn
@@ -8,6 +8,10 @@
  []
  :dev-http {8080 "public"}
  :builds
- {:frontend
+ {:test
+  {:target    :node-test
+   :output-to "out/node-tests.js"
+   :autorun   true}
+  :frontend
   {:target :browser
    :modules {:main {:init-fn dda.masto-embed.app/init}}}}}
diff --git a/src/main/dda/masto_embed/app.cljs b/src/main/dda/masto_embed/app.cljs
index 31f4b2a..006b75a 100644
--- a/src/main/dda/masto_embed/app.cljs
+++ b/src/main/dda/masto_embed/app.cljs
@@ -1,5 +1,8 @@
 (ns dda.masto-embed.app)
 
+(defn add-one [a]
+  (+ a 1))
+
 (defn init
   ""
   []
diff --git a/src/test/dda/masto_embed/app_test.cljs b/src/test/dda/masto_embed/app_test.cljs
new file mode 100644
index 0000000..dcd6033
--- /dev/null
+++ b/src/test/dda/masto_embed/app_test.cljs
@@ -0,0 +1,8 @@
+(ns dda.masto-embed.app-test
+  (:require 
+    [cljs.test :refer (deftest is)]
+    [dda.masto-embed.app :as sut]))
+
+(deftest a-failing-test
+  (is (= 3
+         (sut/add-one 2))))
\ No newline at end of file