Add Deprecation message when loading from latest (#1848)

* add tests to verify if we show an error banner when users load from latest

* add deprecation manager to take care of showing a notification in case script src is being loaded from latest

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* make sure deprecation warning also register onWorker

* restore tests for banner in worker

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* add a wait selector when testing banner since worker seems to take too long to render in CI

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Fix test_deprecate_loading_scripts_from_latest: I think that the
previous failure was because we actually TRIED to execute the js from
latest/core.js and it conflicted with our local copy.

But to trigger the warning is enough to have a script pointing to
pyscript.net/latest, there is no need to execute it: modify it with
type="ignore-me" and an URL which doesn't exist.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Antonio Cuni <anto.cuni@gmail.com>

pyscript.core/tests/integration/support.py

@@ -545,7 +545,9 @@ class PyScriptTest:
           - wait until pyscript has been fully loaded
         """
         doc = self._pyscript_format(
-            snippet, execution_thread=self.execution_thread, extra_head=extra_head
+            snippet,
+            execution_thread=self.execution_thread,
+            extra_head=extra_head,
         )
         if not wait_for_pyscript and timeout is not None:
             raise ValueError("Cannot set a timeout if wait_for_pyscript=False")

pyscript.core/tests/integration/test_warnings_and_banners.py

@@ -1,13 +1,35 @@
 import pytest
 
-from .support import PyScriptTest
-
-pytest.skip(reason="NEXT: Restore the banner", allow_module_level=True)
+from .support import PyScriptTest, skip_worker
 
 
 class TestWarningsAndBanners(PyScriptTest):
     # Test the behavior of generated warning banners
 
+    def test_deprecate_loading_scripts_from_latest(self):
+        # Use a script tag with an invalid output attribute to generate a warning, but only one
+        self.pyscript_run(
+            """
+            <script type="py">
+                print("whatever..")
+            </script>
+            """,
+            extra_head='<script type="ignore-me" src="https://pyscript.net/latest/any-path-triggers-the-warning-anyway.js"></script>',
+        )
+
+        # wait for the banner to appear (we could have a page.locater call but for some reason
+        # the worker takes to long to render on CI, since it's a test we can afford 2 calls)
+        loc = self.page.wait_for_selector(".py-error")
+        assert (
+            loc.inner_text()
+            == "Loading scripts from latest is deprecated and will be removed soon. Please use a specific version instead."
+        )
+
+        # Only one banner should appear
+        loc = self.page.locator(".py-error")
+        assert loc.count() == 1
+
+    @pytest.mark.skip("NEXT: To check if behaviour is consistent with classic")
     def test_create_singular_warning(self):
         # Use a script tag with an invalid output attribute to generate a warning, but only one
         self.pyscript_run(