Follow up of #26861: After removing custom filters and running the script, element blocks are still blocked

[MadhaviSeelam]

Description

Steps to Reproduce

1. Install 1.47.115
2. launch Brave
3. open brave://adblock and add following and click Save changes button

       ##.blocked-class-1
       ##.blocked-class-2
       ##.blocked-class-3

5. visit example.com site
6. Open dev tools console
7. run the script in step 3 from Enable CosmeticFilteringJsPerformance by default #26861 (comment)
8. wait till Done! Scroll to the end to check if there is any visible new element is shown in the console
9. confirmed dynamically added blocks are blocked as expected
10. return to brave://adblock and remove custom filters from above step 3
11. click Save changes button
12. refresh example.com site
13. run the script from step 3
14. wait till Done! Scroll to the end to check if there is any visible new element is shown in the console

Actual result:

Ex1	Ex2

Expected result:

The dynamically added elements blocks are not blocked

ex1	ex2	ex3	ex4

Reproduces how often:

Easily

Brave version (brave://version info)

Brave | 1.47.115 Chromium: 108.0.5359.94 (Official Build) beta (64-bit)
-- | --
Revision | 713576b895246504ccc6b92c2fb8ce2d60194074-refs/branch-heads/5359_71@{#3}
OS | Windows 11 Version 21H2 (Build 22000.1219)

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? N/A

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

@antonok-edm @rebron

cc: @brave/qa-team

[rebron]

@MadhaviSeelam Can you check to see if a browser restart, keeps the expected changes.

[MadhaviSeelam]

@rebron I am still not seeing expected results after browser restart.

[antonok-edm]

Actually... this might be an issue with the empty filters list. If a filter list is empty, it won't get updated when saving. This is because of a slightly hacky workaround that should be fixed when we merge brave/brave-core#16340.

@MadhaviSeelam if you'd like to confirm, try again but make sure the custom filters list isn't empty the second time. For example you could just add a single ! (comment character) in the box.

[MadhaviSeelam]

Closing this issue as it worked as expected with adding ! to the custom filter list (so not to have empty filter list)
(also just to confirm, verified the actual fix of brave/brave-core#16340 in 1.48.132)

ex1	ex2