Display target text on wait_for texts errors.

Author: T4rk1n

Diff for: dash/testing/browser.py

@@ -262,19 +262,28 @@ def _get_element(self, elem_or_selector):
             return self.find_element(elem_or_selector)
         return elem_or_selector
 
-    def _wait_for(self, method, args, timeout, msg):
+    def _wait_for(self, method, timeout, msg):
         """Abstract generic pattern for explicit WebDriverWait."""
-        _wait = (
-            self._wd_wait if timeout is None else WebDriverWait(self.driver, timeout)
-        )
-        logger.debug(
-            "method, timeout, poll => %s %s %s",
-            method,
-            _wait._timeout,  # pylint: disable=protected-access
-            _wait._poll,  # pylint: disable=protected-access
-        )
+        try:
+            _wait = (
+                self._wd_wait
+                if timeout is None
+                else WebDriverWait(self.driver, timeout)
+            )
+            logger.debug(
+                "method, timeout, poll => %s %s %s",
+                method,
+                _wait._timeout,  # pylint: disable=protected-access
+                _wait._poll,  # pylint: disable=protected-access
+            )
 
-        return _wait.until(method(*args), msg)
+            return _wait.until(method)
+        except Exception as err:
+            if callable(msg):
+                message = msg(self.driver)
+            else:
+                message = msg
+            raise TimeoutException(message) from err
 
     def wait_for_element(self, selector, timeout=None):
         """wait_for_element is shortcut to `wait_for_element_by_css_selector`
@@ -286,8 +295,9 @@ def wait_for_element_by_css_selector(self, selector, timeout=None):
         equals to the fixture's `wait_timeout` shortcut to `WebDriverWait` with
         `EC.presence_of_element_located`."""
         return self._wait_for(
-            EC.presence_of_element_located,
-            ((By.CSS_SELECTOR, selector),),
+            EC.presence_of_element_located(
+                (By.CSS_SELECTOR, selector),
+            ),
             timeout,
             f"timeout {timeout or self._wait_timeout}s => waiting for selector {selector}",
         )
@@ -310,8 +320,9 @@ def wait_for_element_by_id(self, element_id, timeout=None):
         equals to the fixture's `wait_timeout` shortcut to `WebDriverWait` with
         `EC.presence_of_element_located`."""
         return self._wait_for(
-            EC.presence_of_element_located,
-            ((By.ID, element_id),),
+            EC.presence_of_element_located(
+                (By.ID, element_id),
+            ),
             timeout,
             f"timeout {timeout or self._wait_timeout}s => waiting for element id {element_id}",
         )
@@ -321,8 +332,7 @@ def wait_for_class_to_equal(self, selector, classname, timeout=None):
         if not set, equals to the fixture's `wait_timeout` shortcut to
         `WebDriverWait` with customized `class_to_equal` condition."""
         return self._wait_for(
-            method=class_to_equal,
-            args=(selector, classname),
+            method=class_to_equal(selector, classname),
             timeout=timeout,
             msg=f"classname => {classname} not found within {timeout or self._wait_timeout}s",
         )
@@ -332,8 +342,7 @@ def wait_for_style_to_equal(self, selector, style, val, timeout=None):
         if not set, equals to the fixture's `wait_timeout` shortcut to
         `WebDriverWait` with customized `style_to_equal` condition."""
         return self._wait_for(
-            method=style_to_equal,
-            args=(selector, style, val),
+            method=style_to_equal(selector, style, val),
             timeout=timeout,
             msg=f"style val => {style} {val} not found within {timeout or self._wait_timeout}s",
         )
@@ -345,11 +354,12 @@ def wait_for_text_to_equal(self, selector, text, timeout=None):
         shortcut to `WebDriverWait` with customized `text_to_equal`
         condition.
         """
+        method = text_to_equal(selector, text, timeout or self.wait_timeout)
+
         return self._wait_for(
-            method=text_to_equal,
-            args=(selector, text),
+            method=method,
             timeout=timeout,
-            msg=f"text -> {text} not found within {timeout or self._wait_timeout}s",
+            msg=method.message,
         )
 
     def wait_for_contains_class(self, selector, classname, timeout=None):
@@ -360,8 +370,7 @@ def wait_for_contains_class(self, selector, classname, timeout=None):
         condition.
         """
         return self._wait_for(
-            method=contains_class,
-            args=(selector, classname),
+            method=contains_class(selector, classname),
             timeout=timeout,
             msg=f"classname -> {classname} not found inside element within {timeout or self._wait_timeout}s",
         )
@@ -373,11 +382,11 @@ def wait_for_contains_text(self, selector, text, timeout=None):
         shortcut to `WebDriverWait` with customized `contains_text`
         condition.
         """
+        method = contains_text(selector, text, timeout or self.wait_timeout)
         return self._wait_for(
-            method=contains_text,
-            args=(selector, text),
+            method=method,
             timeout=timeout,
-            msg=f"text -> {text} not found inside element within {timeout or self._wait_timeout}s",
+            msg=method.message,
         )
 
     def wait_for_page(self, url=None, timeout=10):

Diff for: dash/testing/plugin.py

@@ -22,6 +22,7 @@ def __init__(self, **kwargs):
     )
     from dash.testing.browser import Browser
     from dash.testing.composite import DashComposite, DashRComposite, DashJuliaComposite
+
     _installed = True
 except ImportError:
     # Running pytest without dash[testing] installed.

Diff for: dash/testing/wait.py

@@ -53,9 +53,10 @@ def until_not(
 
 
 class contains_text:
-    def __init__(self, selector, text):
+    def __init__(self, selector, text, timeout):
         self.selector = selector
         self.text = text
+        self.timeout = timeout
 
     def __call__(self, driver):
         try:
@@ -67,6 +68,17 @@ def __call__(self, driver):
         except WebDriverException:
             return False
 
+    def message(self, driver):
+        try:
+            element = self._get_element(driver)
+            text = "found: " + str(element.text) or str(element.get_attribute("value"))
+        except WebDriverException:
+            text = f"{self.selector} not found"
+        return f"text -> {self.text} not found inside element within {self.timeout}s, {text}"
+
+    def _get_element(self, driver):
+        return driver.find_element(By.CSS_SELECTOR, self.selector)
+
 
 class contains_class:
     def __init__(self, selector, classname):
@@ -86,13 +98,14 @@ def __call__(self, driver):
 
 
 class text_to_equal:
-    def __init__(self, selector, text):
+    def __init__(self, selector, text, timeout):
         self.selector = selector
         self.text = text
+        self.timeout = timeout
 
     def __call__(self, driver):
         try:
-            elem = driver.find_element(By.CSS_SELECTOR, self.selector)
+            elem = self._get_element(driver)
             logger.debug("text to equal {%s} => expected %s", elem.text, self.text)
             return (
                 str(elem.text) == self.text
@@ -101,6 +114,17 @@ def __call__(self, driver):
         except WebDriverException:
             return False
 
+    def message(self, driver):
+        try:
+            element = self._get_element(driver)
+            text = "found: " + str(element.text) or str(element.get_attribute("value"))
+        except WebDriverException:
+            text = f"{self.selector} not found"
+        return f"text -> {self.text} not found within {self.timeout}s, {text}"
+
+    def _get_element(self, driver):
+        return driver.find_element(By.CSS_SELECTOR, self.selector)
+
 
 class style_to_equal:
     def __init__(self, selector, style, val):

Diff for: tests/integration/test_duo.py

@@ -0,0 +1,36 @@
+import pytest
+from selenium.common.exceptions import TimeoutException
+
+from dash import Dash, html
+
+
+def test_duo001_wait_for_text_error(dash_duo):
+    app = Dash(__name__)
+    app.layout = html.Div([html.Div("Content", id="content")])
+    dash_duo.start_server(app)
+
+    with pytest.raises(TimeoutException) as err:
+        dash_duo.wait_for_text_to_equal("#content", "Invalid", timeout=1.0)
+
+    assert err.value.args[0] == "text -> Invalid not found within 1.0s, found: Content"
+
+    with pytest.raises(TimeoutException) as err:
+        dash_duo.wait_for_text_to_equal("#none", "None", timeout=1.0)
+
+    assert err.value.args[0] == "text -> None not found within 1.0s, #none not found"
+
+    with pytest.raises(TimeoutException) as err:
+        dash_duo.wait_for_contains_text("#content", "invalid", timeout=1.0)
+
+    assert (
+        err.value.args[0]
+        == "text -> invalid not found inside element within 1.0s, found: Content"
+    )
+
+    with pytest.raises(TimeoutException) as err:
+        dash_duo.wait_for_contains_text("#none", "none", timeout=1.0)
+
+    assert (
+        err.value.args[0]
+        == "text -> none not found inside element within 1.0s, #none not found"
+    )