Add redraw test.

Author: T4rk1n

@plotly/dash-test-components/src/components/DrawCounter.js

@@ -0,0 +1,15 @@
+import React, { useState, useEffect } from "react";
+import PropTypes from "prop-types";
+
+const DrawCounter = (props) => {
+    const [count, setCount] = useState(0);
+    useEffect(() => {
+        setCount(count + 1);
+    }, [props]);
+    return <div id={props.id}>{count}</div>;
+};
+
+DrawCounter.propTypes = {
+    id: PropTypes.string,
+};
+export default DrawCounter;

@plotly/dash-test-components/src/index.js

@@ -7,6 +7,7 @@ import MyPersistedComponentNested from './components/MyPersistedComponentNested'
 import StyledComponent from './components/StyledComponent';
 import WidthComponent from './components/WidthComponent';
 import ComponentAsProp from './components/ComponentAsProp';
+import DrawCounter from './components/DrawCounter';
 
 export {
     AsyncComponent,
@@ -18,4 +19,5 @@ export {
     StyledComponent,
     WidthComponent,
     ComponentAsProp,
+    DrawCounter,
 };

tests/integration/renderer/test_redraw.py

@@ -0,0 +1,34 @@
+import time
+from dash import Dash, Input, Output, html
+
+import dash_test_components as dt
+
+
+def test_rdraw001_redraw(dash_duo):
+    app = Dash()
+
+    app.layout = html.Div(
+        [
+            html.Div(
+                dt.DrawCounter(id="counter"),
+                id="redrawer",
+            ),
+            html.Button("redraw", id="redraw"),
+        ]
+    )
+
+    @app.callback(
+        Output("redrawer", "children"),
+        Input("redraw", "n_clicks"),
+        prevent_initial_call=True,
+    )
+    def on_click(_):
+        return dt.DrawCounter(id="counter")
+
+    dash_duo.start_server(app)
+
+    dash_duo.wait_for_text_to_equal("#counter", "1")
+    dash_duo.find_element("#redraw").click()
+    dash_duo.wait_for_text_to_equal("#counter", "2")
+    time.sleep(1)
+    dash_duo.wait_for_text_to_equal("#counter", "2")