diff --git a/deno/add.test.ts b/deno/add.test.ts
new file mode 100644
index 0000000..89f8cb5
--- /dev/null
+++ b/deno/add.test.ts
@@ -0,0 +1,9 @@
+import { assertStrictEquals } from "testing/asserts.ts";
+import { add } from "./add.ts";
+
+Deno.test({
+  name: "add",
+  fn() {
+    assertStrictEquals(add(1, 2), 3);
+  },
+});
diff --git a/deno/add.ts b/deno/add.ts
new file mode 100644
index 0000000..bc81dd5
--- /dev/null
+++ b/deno/add.ts
@@ -0,0 +1 @@
+export const add = (a: number, b: number) => a + b;
diff --git a/deno/app.ts b/deno/app.ts
index c67e6be..444c9ae 100644
--- a/deno/app.ts
+++ b/deno/app.ts
@@ -1,4 +1,4 @@
-import { Handler, ServeInit, serve } from "http/server.ts";
+import { Handler, serve, ServeInit } from "http/server.ts";
 
 const handler: Handler = () => new Response("Hello World\n");
 const options: ServeInit = { addr: "localhost:8080" };
diff --git a/deno/deno.json b/deno/deno.json
new file mode 100644
index 0000000..6516167
--- /dev/null
+++ b/deno/deno.json
@@ -0,0 +1,8 @@
+{
+  "$schema": "https://raw.githubusercontent.com/denoland/deno/main/cli/schemas/config-file.v1.json",
+  "lint": {
+    "rules": {
+      "include": ["default-param-last", "eqeqeq"]
+    }
+  }
+}
diff --git a/deno/importmap.json b/deno/importmap.json
index 42d1a9a..237ce2e 100644
--- a/deno/importmap.json
+++ b/deno/importmap.json
@@ -1,5 +1,6 @@
 {
   "imports": {
-    "http/": "https://deno.land/std@0.115.1/http/"
+    "http/": "https://deno.land/std@0.115.1/http/",
+    "testing/": "https://deno.land/std@0.116.0/testing/"
   }
 }
diff --git a/deno/scripts.yml b/deno/scripts.yml
index 31fdd80..528301b 100644
--- a/deno/scripts.yml
+++ b/deno/scripts.yml
@@ -1,6 +1,12 @@
 # yaml-language-server: $schema=https://deno.land/x/denon@2.4.10/schema.json
-importmap: importmap.json
+
 scripts:
   start:
-    cmd: "deno run app.ts"
+    cmd: "deno run --import-map=importmap.json app.ts"
     allow: [net]
+  test:
+    cmd: "deno test --import-map=importmap.json"
+  lint:
+    cmd: "deno lint --config=deno.json ."
+  fmt:
+    cmd: "deno fmt --config=deno.json ."