diff --git a/test/elin/interceptor/connect/shadow_cljs_test.clj b/test/elin/interceptor/connect/shadow_cljs_test.clj
new file mode 100644
index 0000000..5c23c0d
--- /dev/null
+++ b/test/elin/interceptor/connect/shadow_cljs_test.clj
@@ -0,0 +1,49 @@
+(ns elin.interceptor.connect.shadow-cljs-test
+  (:require
+   [clojure.core.async :as async]
+   [clojure.java.io :as io]
+   [clojure.test :as t]
+   [elin.function.select :as e.f.select]
+   [elin.interceptor.connect.shadow-cljs :as sut]
+   [elin.protocol.host :as e.p.host]
+   [elin.test-helper :as h]
+   [elin.util.file :as e.u.file]))
+
+(t/use-fixtures :once h/malli-instrument-fixture)
+(t/use-fixtures :once h/warn-log-level-fixture)
+
+(def ^:private detect-shadow-cljs-port-enter
+  (:enter sut/detect-shadow-cljs-port))
+
+;; (def ^:private detect-shadow-cljs-port-leave
+;;   (:leave sut/detect-shadow-cljs-port))
+
+(t/deftest detect-shadow-cljs-port-enter-test
+  (let [cwd (.getAbsolutePath (io/file "."))
+        test-elin (h/test-elin)
+        detect-shadow-cljs-port-enter-test (fn [hostname port-file]
+                                             (-> test-elin
+                                                 (assoc :hostname hostname
+                                                        :port-file port-file)
+                                                 (detect-shadow-cljs-port-enter)
+                                                 (select-keys [:hostname port-file])))]
+    (t/testing "Positive"
+      (t/testing "No shadow-cljs port file"
+        (with-redefs [e.p.host/get-current-working-directory! (fn [& _]
+                                                                (async/go cwd))
+                      e.f.select/select-from-candidates (fn [_ candidates]
+                                                          (first candidates))]
+          (t/is (= {:hostname nil}
+                   (detect-shadow-cljs-port-enter-test nil nil)))))
+
+      (t/testing "Exists shadow-cljs port file, but not selected")
+      (t/testing "Exists shadow-cljs port file, and selected")
+
+      (t/testing "Failed to fetch project root directory"
+        (with-redefs [e.p.host/get-current-working-directory! (fn [& _]
+                                                                (async/go cwd))
+                      e.u.file/get-project-root-directory (constantly nil)]
+          (t/is (= {:hostname nil}
+                   (detect-shadow-cljs-port-enter-test nil nil))))))
+
+    (t/testing "Negative")))