diff --git a/repo2readme/utils/detect_language.py b/repo2readme/utils/detect_language.py
index 8f84621..0ba4003 100644
--- a/repo2readme/utils/detect_language.py
+++ b/repo2readme/utils/detect_language.py
@@ -29,6 +29,10 @@
     ".css": "css",
 }
 
-def detect_lang(path:str):
-    _,extension=os.path.splitext(path)
-    return EXTENSION_LANGUAGE_MAP.get(extension,"unknown")
\ No newline at end of file
+def detect_lang(path: str) -> str:
+    _, extension = os.path.splitext(path)
+
+    if not extension and path.startswith("."):
+        extension = path
+
+    return EXTENSION_LANGUAGE_MAP.get(extension.lower(), "unknown")
\ No newline at end of file
diff --git a/tests/test_detect_language.py b/tests/test_detect_language.py
new file mode 100644
index 0000000..3aca1b6
--- /dev/null
+++ b/tests/test_detect_language.py
@@ -0,0 +1,21 @@
+from repo2readme.utils.detect_language import detect_lang
+
+
+def test_detect_lang_with_extension_only():
+    assert detect_lang(".py") == "python"
+    assert detect_lang(".js") == "javascript"
+    assert detect_lang(".cpp") == "cpp"
+    assert detect_lang(".md") == "markdown"
+    assert detect_lang(".json") == "json"
+
+
+def test_detect_lang_with_path():
+    assert detect_lang("main.py") == "python"
+    assert detect_lang("index.js") == "javascript"
+    assert detect_lang("src/config.yaml") == "yaml"
+
+
+def test_detect_lang_unknown():
+    assert detect_lang(".unknown") == "unknown"
+    assert detect_lang("README") == "unknown"
+    assert detect_lang(".txt") == "unknown"
\ No newline at end of file