After reading a blog post by Matthias Noback on keeping an eye on code churn, I was motivated to run the churn php library over some modules in core to gauge the level of churn.

Is this something you might like to do on your modules? Read on for more information.

by
Lee Rowlands
/ 19 January 2018

What is churn

As Matthias details in his blog post - churn is a measure of the number of times a piece of code has been changed over time. The red flags start to crop up when you have high complexity and high churn.

Enter churn-php

Churn php is a library that analyses PHP code that has its history in git to identify high churn/complexity scores.

You can either install it with composer require bmitch/churn-php --dev or run it using docker docker run --rm -ti -v $PWD:/app dockerizedphp/churn run /path/to/code

Some results from core

So I ran it for some modules I look after in core, as well as the Drupal\Core\Entity namespace.

Block Content

File
Times Changed
Complexity
Score
core/modules/block_content/src/Entity/BlockContent.php
41
6
1
core/modules/block_content/src/BlockContentForm.php
32
6
0.78
core/modules/block_content/src/Plugin/Block/BlockContentBlock.php
20
6
0.488
core/modules/block_content/src/Tests/BlockContentTestBase.php
16
6
0.39
core/modules/block_content/src/BlockContentTypeForm.php
18
4
0.347
core/modules/block_content/src/Controller/BlockContentController.php
8
6
0.195
Comment

File
Times Changed
Complexity
Score
core/modules/comment/src/CommentForm.php
60
45
1
core/modules/comment/src/Entity/Comment.php
55
25
0.548
core/modules/comment/src/Tests/CommentTestBase.php
33
29
0.426
core/modules/comment/src/Controller/CommentController.php
32
20
0.274
core/modules/comment/src/CommentViewBuilder.php
37
16
0.25
core/modules/comment/src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
32
18
0.24
core/modules/comment/src/Form/CommentAdminOverview.php
29
17
0.191
core/modules/comment/src/CommentAccessControlHandler.php
17
28
0.19
core/modules/comment/src/CommentLinkBuilder.php
15
29
0.17
core/modules/comment/src/CommentManager.php
29
15
0.157
Drupal\Core\Entity

File
Times Changed
Complexity
Score
core/lib/Drupal/Core/Entity/ContentEntityBase.php
115
173
0.808
core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
61
196
0.465
core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
56
203
0.427
core/lib/Drupal/Core/Entity/Entity.php
131
43
0.212
core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
41
105
0.16
Conclusion

So, what to do with these results?

Well I think if you're looking to simplify your code-base and identify places that would warrant refactoring, those with a high 'churn' score would be a good place to start.

What do you think? Let us know in the comments.

Tagged

Drupal Core, Code Complexity, Drupal 8