fix: docs rest model (#661)

quetz/rest_models.py

@@ -134,7 +134,7 @@ class ChannelMetadata(BaseModel):
 
 class Channel(ChannelBase):
     metadata: ChannelMetadata = Field(
-        default_factory=ChannelMetadata, title="channel metadata", examples={}
+        default_factory=ChannelMetadata, title="channel metadata", examples=[]
     )
 
     actions: Optional[List[ChannelActionEnum]] = Field(

quetz/tests/test_docs.py

@@ -0,0 +1,16 @@
+def test_docs_endpoint(client):
+    response = client.get("/docs")
+    assert response.status_code == 200
+    assert "text/html" in response.headers['Content-Type']
+
+
+def test_openapi_endpoint(client):
+    response = client.get("/openapi.json")
+    assert response.status_code == 200
+    assert "application/json" in response.headers['Content-Type']
+
+
+def test_redoc_endpoint(client):
+    response = client.get("/redoc")
+    assert response.status_code == 200
+    assert "text/html" in response.headers['Content-Type']