Skip to content

[AssetMapper] Adding CSP details, recommending script-src 'strict-dynamic' #21356

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: 6.4
Choose a base branch
from
Open

[AssetMapper] Adding CSP details, recommending script-src 'strict-dynamic' #21356

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions frontend/asset_mapper.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -476,10 +476,14 @@ the page as ``link`` tags in the order they were imported.
.. note::

Importing a CSS file is *not* something that is natively supported by
JavaScript modules. AssetMapper makes this work by adding a special importmap
entry for each CSS file. These special entries are valid, but do nothing.
JavaScript modules. AssetMapper makes this work by adding an empty importmap
entry for each CSS file, e.g. ``"/assets/app.css": "data:application/javascript,",``.
These special entries are valid, but do nothing.
AssetMapper adds a ``<link>`` tag for each CSS file, but when JavaScript
executes the ``import`` statement, nothing additional happens.
When using a **Content-Security-Policy** with ``script-src 'self'``, this
will trigger an error because of the ``data:`` URL. You can either just
ignore the error, or lower the rule to ``script-src 'strict-dynamic'``.
Copy link
Preview

Copilot AI Sep 9, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

[nitpick] The phrase 'lower the rule' is unclear and potentially confusing. Using 'strict-dynamic' is not necessarily 'lowering' security - it's a different security model. Consider rephrasing to 'change the rule to' or 'use' instead of 'lower the rule to'.

Suggested change
ignore the error, or lower the rule to ``script-src 'strict-dynamic'``.
ignore the error, or change the rule to ``script-src 'strict-dynamic'``.

Copilot uses AI. Check for mistakes.


.. _asset-mapper-3rd-party-css:

Expand Down