fix: add migration to remove old ckeditor table

[earthcomfy]

This PR attempts to add a migration file to remove the old ckeditor table.
Fixes #60

Summary by Sourcery

Bug Fixes:

• Removes a stale database table from a previous version of the application to avoid conflicts.

[sourcery-ai]

Reviewer's Guide by Sourcery

This pull request adds a migration to remove the old djangocms_text_ckeditor_text table. The migration checks if the table exists and drops it if it does, using a database-specific command to handle potential dependencies.

No diagrams generated as the changes look simple and do not need a visual representation.

File-Level Changes

Change	Details	Files
Added a data migration to remove the old CKEditor table.	Implemented a function drop_table_if_exists to conditionally drop the table. Used schema_editor.connection.introspection.table_names() to check for the table's existence. Included a database-specific command for PostgreSQL to handle CASCADE deletion. Added a migration that runs the drop_table_if_exists function. Added a no-op reverse code to prevent issues during migration rollback.	djangocms_text/migrations/0004_remove_old_ckeditor_table.py

Possibly linked issues

• #123: The PR fixes the issue by adding a migration to remove the old ckeditor table.

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[sourcery-ai]

Hey @earthcomfy - I've reviewed your changes - here's some feedback:

Overall Comments:

• Consider adding a comment to explain why the table needs to be dropped.
• It might be safer to check if the table exists within the drop_table_if_exists function using apps.get_model rather than relying on schema_editor.connection.introspection.table_names().

Here's what I looked at during the review

• 🟡 General issues: 1 issue found
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

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[sourcery-ai]

suggestion (typo): Add a comma after 'djangocms-text-ckeditor'.

The sentence would read better with a comma after 'djangocms-text-ckeditor'.

Suggested change

	from djangocms-text-ckeditor and clean up old tables. All you have to do is:
	from djangocms-text-ckeditor, and clean up old tables. All you have to do is:

[earthcomfy]

I used schema_editor because it provides a Django-agnostic way to manage database schema changes. Also, the previous migration file uses it.

[DmytroLitvinov]

HI there,
Should it be really in the package's migration instead of mentioning it in case someone is migrated?

My concern is that it automatically drops the tables.

[earthcomfy]

@DmytroLitvinov I brought this idea in the issue and thought we wanted to move forward with this approach. @fsbraun

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 5 lines in your changes missing coverage. Please review.

Project coverage is 81.30%. Comparing base (30f539b) to head (ff8b8ca).

Files with missing lines	Patch %	Lines
..._text/migrations/0004_remove_old_ckeditor_table.py	50.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #61      +/-   ##
==========================================
- Coverage   81.63%   81.30%   -0.34%     
==========================================
  Files          17       18       +1     
  Lines         942      952      +10     
  Branches      105      107       +2     
==========================================
+ Hits          769      774       +5     
- Misses        130      135       +5     
  Partials       43       43              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[fsbraun]

@DmytroLitvinov Any regular migration would replace the old model by the new one retaining already existing data (if possible). This is also the case for this migration. I would second adding it. (Thanks, @earthcomfy )

It might be worthwhile mentioning that one can avoid the old tables to be dropped if migrations are run up to 0003 and 0004 is faked. Maybe we can add this to the migration guide in the readme? The issue of doing this will be potential constraints.

[fsbraun]

@earthcomfy Why is the CASCADE command important for Postgres? Can you comment how you tested this (with Postgres and which databases)?

[earthcomfy]

@fsbraun I tested this by creating a test project inside my branch. I first added djangocms_text_ckeditor into my installed apps and when I run migrate it creates the djangocms_text_ckeditor_text table. Then I replaced the installation with djangocms_text and run migrate. This applies all the migration files including the drop table and the table no longer exists.

I also tested this both with sqlite and postgres.

I added cascade because of the description mentioned in the issue. In PostgreSQL, to drop a table that is referenced by a view or a foreign-key constraint of another table, we have to use cascade. That is my thought process.