Added 3 new tests for promise handling

Author: MrTeale

CHANGELOG.md

@@ -2,7 +2,7 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
-## [2.3.2]
+## [Unreleased]
 
 ### Added
 

tests/integration/clientside/assets/clientside.js

@@ -53,7 +53,7 @@ window.dash_clientside.clientside = {
                         'side effect'
                     );
                 }, 100);
-                resolve('output');
+                resolve('foo');
             }, 1);
         });
     },
@@ -98,5 +98,27 @@ window.dash_clientside.clientside = {
         }
         window.callCount += 1;
         return inputValue.toString();
-    }
+    },
+
+    chained_promise: function (inputValue) {
+        return new Promise(function (resolve) {
+            setTimeout(function () {
+                resolve(inputValue + "-chained");
+            }, 100);
+        });
+    },
+
+    delayed_promise: function (inputValue) {
+        return new Promise(function (resolve) {
+            window.callbackDone = function (deferredValue) {
+                resolve("clientside-" + inputValue + "-" + deferredValue);
+            };
+        });
+    },
+
+    non_delayed_promise: function (inputValue) {
+        return new Promise(function (resolve) {
+            resolve("clientside-" + inputValue);
+        });
+    },
 };

tests/integration/clientside/test_clientside.py

@@ -1,5 +1,6 @@
 # -*- coding: UTF-8 -*-
-from multiprocessing import Value
+from multiprocessing import Value, Lock
+import pytest
 
 from dash import Dash, Input, Output, State, ClientsideFunction, ALL, html, dcc
 from selenium.webdriver.common.keys import Keys
@@ -223,6 +224,7 @@ def test_clsd004_clientside_multiple_outputs(dash_duo):
         dash_duo.wait_for_text_to_equal(selector, expected)
 
 
+@pytest.mark.xfail(reason="Promises are now handled within Dash-Renderer")
 def test_clsd005_clientside_fails_when_returning_a_promise(dash_duo):
     app = Dash(__name__, assets_folder="assets")
 
@@ -716,3 +718,90 @@ def test_clsd014_input_output_callback(dash_duo):
     assert call_count == 2, "initial + changed once"
 
     assert dash_duo.get_logs() == []
+
+
+def test_clsd015_clientside_chained_callbacks_returning_promise(dash_duo):
+    app = Dash(__name__, assets_folder="assets")
+
+    app.layout = html.Div(
+        [
+            html.Div(id="input", children=["initial"]),
+            html.Div(id="div-1"),
+            html.Div(id="div-2"),
+        ]
+    )
+
+    app.clientside_callback(
+        ClientsideFunction(namespace="clientside", function_name="chained_promise"),
+        Output("div-1", "children"),
+        Input("input", "children"),
+    )
+
+    @app.callback(Output("div-2", "children"), Input("div-1", "children"))
+    def callback(value):
+        return value + "-twice"
+
+    dash_duo.start_server(app)
+
+    dash_duo.wait_for_text_to_equal("#div-1", "initial-chained")
+    dash_duo.wait_for_text_to_equal("#div-2", "initial-chained-twice")
+
+
+def test_clsd016_serverside_clientside_shared_input_with_promise(dash_duo):
+    app = Dash(__name__, assets_folder="assets")
+
+    app.layout = html.Div(
+        [
+            html.Div(id="input", children=["initial"]),
+            html.Div(id="clientside-div"),
+            html.Div(id="serverside-div"),
+        ]
+    )
+
+    app.clientside_callback(
+        ClientsideFunction(namespace="clientside", function_name="delayed_promise"),
+        Output("clientside-div", "children"),
+        Input("input", "children"),
+    )
+
+    @app.callback(Output("serverside-div", "children"), Input("input", "children"))
+    def callback(value):
+        return "serverside-" + value[0]
+
+    dash_duo.start_server(app)
+
+    dash_duo.wait_for_text_to_equal("#serverside-div", "serverside-initial")
+    dash_duo.driver.execute_script("window.callbackDone('deferred')")
+    dash_duo.wait_for_text_to_equal("#clientside-div", "clientside-initial-deferred")
+
+
+def test_clsd017_clientside_serverside_shared_input_with_promise(dash_duo):
+    lock = Lock()
+    lock.acquire()
+
+    app = Dash(__name__, assets_folder="assets")
+
+    app.layout = html.Div(
+        [
+            html.Div(id="input", children=["initial"]),
+            html.Div(id="clientside-div"),
+            html.Div(id="serverside-div"),
+        ]
+    )
+
+    app.clientside_callback(
+        ClientsideFunction(namespace="clientside", function_name="non_delayed_promise"),
+        Output("clientside-div", "children"),
+        Input("input", "children"),
+    )
+
+    @app.callback(Output("serverside-div", "children"), Input("input", "children"))
+    def callback(value):
+        with lock:
+            return "serverside-" + value[0] + "-deferred"
+
+    dash_duo.start_server(app)
+
+    dash_duo.wait_for_text_to_equal("#clientside-div", "clientside-initial")
+    lock.release()
+    dash_duo.wait_for_text_to_equal("#serverside-div", "serverside-initial-deferred")