Start using a defhandler macro for defining handlers (#69)

* Start using a defhandler macro for defining handlers

* Polylith commands

* Fix tests

* Fix linting

Author: bryanmikaelian

.claude/settings.local.json

@@ -0,0 +1,8 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(clj:*)"
+    ],
+    "deny": []
+  }
+}

CLAUDE.md

@@ -45,7 +45,6 @@ bb psql-test  # Connect to test PostgreSQL database
 **REPL Development:**
 ```bash
 clj -M:dev:repl    # Development REPL
-clj -M:test:repl   # Test REPL
 ```
 
 **Build Commands:**
@@ -56,8 +55,18 @@ clj -T:build uberjar :project agent     # Build agent uberjar
 
 **Testing:**
 ```bash
-# Test runner is configured in tests.edn using Kaocha
-clj -M:poly test
+clj -M:poly test       # Run tests for all projects
+```
+
+**Polylith Commands:**
+```bash
+clj -M:poly info       # Show workspace info and project structure
+clj -M:poly deps       # Show dependencies between components
+clj -M:poly check      # Check for circular dependencies and issues
+clj -M:poly diff       # Show what has changed since last tag
+clj -M:poly create component name:my-component    # Create new component
+clj -M:poly create base name:my-base              # Create new base
+clj -M:poly create project name:my-project        # Create new project
 ```
 
 ## Development Workflow

components/http/src/com/vennbilling/http/core.clj

@@ -0,0 +1,28 @@
+(ns com.vennbilling.http.core
+  (:require [ring.util.http-response :as http]))
+
+(defn respond-with
+  "Converts handler result tuples like [:ok data] into proper HTTP responses"
+  [result]
+  (let [[status body] result]
+    (case status
+      :ok (http/ok body)
+      :created (http/created "" body)
+      :no-content (http/no-content)
+      :bad-request (http/bad-request body)
+      :not-found (http/not-found body)
+      (http/bad-request body))))
+
+(defmacro defhandler
+  "Defines a handler function that automatically applies respond-with to the result.
+   
+   Usage:
+   (defhandler my-handler [request]
+     [:ok {:message \"Hello\"}])
+   
+   This is equivalent to:
+   (defn my-handler [request]
+     (respond-with [:ok {:message \"Hello\"}]))"
+  [name args & body]
+  `(defn ~name ~args
+     (respond-with (do ~@body))))

components/http/src/com/vennbilling/http/interface.clj

@@ -1,5 +1,6 @@
 (ns com.vennbilling.http.interface
-  (:require [com.vennbilling.http.ring :as ring]
+  (:require [com.vennbilling.http.core :as core]
+            [com.vennbilling.http.ring :as ring]
             [com.vennbilling.http.routes :as routes]
             [com.vennbilling.http.undertow :as undertow]))
 
@@ -10,6 +11,13 @@
 (def server-routes
   [routes/customers])
 
+(defmacro defhandler
+  "Defines a handler function that automatically applies respond-with to the result.
+   See com.vennbilling.http.core/defhandler for implementation details."
+  {:clj-kondo/lint {:lint-as {core/defhandler clojure.core/fn}}}
+  [name args & body]
+  `(core/defhandler ~name ~args ~@body))
+
 (defn serve
   "Starts up an HTTP server with a io.undertow config and ring handler. Returns an undertow server"
   [config handler]

components/http/src/com/vennbilling/http/routes.clj

@@ -2,50 +2,39 @@
   (:require [com.vennbilling.customer.interface :as customer]
             [com.vennbilling.healthcheck.interface :as healthcheck]
             [com.vennbilling.spec.interface :as spec]
-            [ring.util.http-response :as http]
+            [com.vennbilling.http.core :as core]
             [ring.util.http-status :as http-status]))
 
-(defn- respond-with
-  [result]
-  (let [[status body] result]
-    (case status
-      :ok (http/ok body)
-      :created (http/created "" body)
-      :no-content (http/no-content)
-      :bad-request (http/bad-request body)
-      :not-found (http/not-found body)
-      (http/bad-request body))))
-
 (def healthchecks
   [["/health"
     {:get {:responses {http-status/ok {:body map?}
                        http-status/internal-server-error {}}
-           :handler (comp respond-with healthcheck/simple-handler)}}]])
+           :handler (comp core/respond-with healthcheck/simple-handler)}}]])
 
 (def spec
   [["/identify"
     {:post {:parameters {:body customer/Schema}
             :responses {http-status/created {:body customer/Schema}}
-            :handler (comp respond-with spec/identify-handler)}}]
+            :handler (comp core/respond-with spec/identify-handler)}}]
 
    ["/charge"
     {:post {:parameters {:body spec/Schema}
-            :handler (comp respond-with spec/charge-handler)}}]
+            :handler (comp core/respond-with spec/charge-handler)}}]
 
    ["/usage"
     {:post {:parameters {:body spec/Schema}
-            :handler (comp respond-with spec/usage-handler)}}]
+            :handler (comp core/respond-with spec/usage-handler)}}]
 
    ["/reverse"
     {:post {:parameters {:body spec/Schema}
-            :handler (comp respond-with spec/reverse-handler)}}]])
+            :handler (comp core/respond-with spec/reverse-handler)}}]])
 
 (def customers
   ["/customers"
    [""
     {:get {:responses {http-status/ok {:body [:vector customer/Schema]}}
-           :handler (comp respond-with customer/list-handler)}}]
+           :handler (comp core/respond-with customer/list-handler)}}]
    ["/:id"
     {:get {:responses {http-status/ok {:body customer/Schema}
                        http-status/not-found {}}
-           :handler (comp respond-with customer/show-handler)}}]])
+           :handler (comp core/respond-with customer/show-handler)}}]])

components/http/test/com/vennbilling/http/interface_test.clj

@@ -1 +1,22 @@
-(ns com.vennbilling.http.interface-test)
+(ns com.vennbilling.http.interface-test
+  (:require
+   [clojure.test :refer [deftest testing is]]
+   [com.vennbilling.http.interface :refer [defhandler]]))
+
+(defhandler test-handler [_request]
+  [:ok {:message "test"}])
+
+(defhandler test-created-handler [_request]
+  [:created {:id 123}])
+
+(deftest defhandler-macro-test
+  (testing "defhandler macro creates proper HTTP responses"
+    (testing "ok response"
+      (let [response (test-handler {})]
+        (is (= 200 (:status response)))
+        (is (= {:message "test"} (:body response)))))
+
+    (testing "created response"
+      (let [response (test-created-handler {})]
+        (is (= 201 (:status response)))
+        (is (= {:id 123} (:body response)))))))