[Django] #32849: ManifestStaticFilesStorage newline breaks regex

[Django]

#32849: ManifestStaticFilesStorage newline breaks regex
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Reporter: TZanke | Owner: nobody
Type: Bug | Status: new
Component: contrib.staticfiles | Version: 3.2
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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Hello,

I am trying to use the `ManifestStaticFilesStorage` static file handling.
Right now i found a possible issue with line breaks.

The file in which strings should be replaced is loaded as a string with
line breaks:
https://github.com/django/django/blob/main/django/contrib/staticfiles/storage.py#L315

The default regex may not have this issue, `default_template =
"""url("%(url)s")"""` cause a minifier will not break inside this `url()`
method.
https://github.com/django/django/blob/main/django/contrib/staticfiles/storage.py#L45

But in my case a more complex string with URL has to be replaced, so
currently the string sometimes contains a line break.
The line break now is not matched against the regex which leads to a
caching problem.

Expample:
CKEditor4: https://cdn.ckeditor.com/4.16.1/standard/ckeditor.js
Search for "styles/tableselection.css"
First occurrence is split by line break.

My regex: `(appendStyleSheet\(this\.path\+"([^'"]*?)"\))`
Regex with newline support:
`(appendStyleSheet\(this\s?\.\s?path\s?\+\s?"([^'"]*?)"\))`

Question:
Who is responsible for possible line breaks?
Maybe Django should load the content without line breaks?
Or has the developer/user of ManifestStaticFilesStorage a responsibility
to care for possible line breaks in his regexes?

But: Maybe he (the developer) does not know this can happen. Later on,
someone else changes the JS code => minifyer adds linebreaks => production
=> regex mismatch => caching problem

Let me know whats your opinion.

Best regards
Tobias

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Ticket URL: <https://code.djangoproject.com/ticket/32849>
Django <https://code.djangoproject.com/>
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[Django]

#32849: ManifestStaticFilesStorage newline breaks regex

-------------------------------------+------------------------------------

Reporter: TZanke | Owner: nobody
Type: Bug | Status: new
Component: contrib.staticfiles | Version: 3.2

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

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Changes (by Carlton Gibson):

* stage: Unreviewed => Accepted

Comment:

Hi Tobias. Thanks for the report.

I'm not 100% sure, but let's provisionally Accept to see what a PR looks
like.

If you can reduce that CKEditor example to a minimum case, that would
help.
(Can we always strip `\n` in JS without loss? — minifiers often output on
one line, no? 🤔)

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Ticket URL: <https://code.djangoproject.com/ticket/32849#comment:1>

[Django]

#32849: ManifestStaticFilesStorage newline breaks regex

-------------------------------------+------------------------------------

Reporter: TZanke | Owner: nobody
Type: Bug | Status: new
Component: contrib.staticfiles | Version: 3.2

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------------+------------------------------------

Comment (by Keryn Knight):

Replying to [comment:1 Carlton Gibson]:
> (Can we always strip `\n` in JS without loss? [...])

''Possibly'' not, due to the rules around Automatic Semi-colon Insertion
(similar to how white-space is sort-of significant in HTML). I'd presume
any/all minifiers do explicit insertion in such cases to avoid affecting
the intended output...

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Ticket URL: <https://code.djangoproject.com/ticket/32849#comment:2>