rubocop assignment branch condition size for is too high

Red Green Repeat Adventures of a Spec Driven Junkie

Understanding assignment branch condition.

Recently, I integrated Rubocop into my work flow and it’s been very humbling. I feel I’m a great coder with all the specs passing and doing a good job of refactoring, Rubocop always finds something wrong with my code.

I usually go back and make fixes based on Rubocop’s suggestions, but I keep running into the same few issues and solving them isn’t as easy as using: rubocop -a (which auto-corrects all the easy ones!)

The toughest offense for me so far: Assignment Branch Condition

This offense is harder to fix really make me think about my coding style in general. I want to learn more about this offense to help me understand. By understanding, my goals is to not make this offense so often and/or make it easier for me to fix in the future.

What is: ABC?

Rubocop message:

The default is 15 and the first pass of my code is always way past this, probably on average twice this value. So cleaning up my code to meet the default value really takes a lot of work.

From the documentation :

Really Understanding: ABC

Let’s understand what ABC is by checking out the definition of ABC :

Broken down:

• assignments (anything with = )
• branches (anything that jumps out of the current method)
• conditionals (anything that tests logic if , case , unary ? )

SO, to reduce the ABC value, reduce assignments (use less intermediate variables), fewer branches (calling other methods), and conditionals (if/else statements).

Computing ABC

The ABC value is not just a counting of them, but a square root of the sum of their squares. If any one of them getting too high will spike the ABC count.

The Rubocop default for ABC metric is 15. What does 15 really mean?

Well, doing the math, to get an ABC score of 15, a method would have:

• 8 assignments
• 8 conditionals

(Just working backwards from 15*15 => 225; 225/3 => 75; Math.sqrt(75) ~=> 8.66)

Now that I lay it out that way, an ABC value of 15 is very reasonable. Having eight of each for a method is just enough to do a lot of work in a method, but a value of 15 keeps the method from spiraling out of control in assignments, branches, or conditionals.

Whenever I encountered Rubocop’s ‘ABC is too high’ message, I was annoyed with ABC metric because I didn’t understand how it was computed and I couldn’t refactor efficiently to lower the ABC value quickly.

Now that I spent some effort into researching what Assignment Branch Condition really means, I feel better about creating or refactoring code that has a better ABC score.

DEV Community

Posted on Jun 26, 2020 • Updated on Aug 3, 2020 • Originally published at thedevpost.com

11 Most Asked Questions About RuboCop

RuboCop is a Ruby static code analyzer and code formatter which helps to track errors easily and fix minor code issues during the development process saving your time. It has many advantages and you can learn more about RuboCop on https://docs.rubocop.org/en/stable/ .

Today, we will be talking about the most asked questions about RuboCop.

1. How to check if record exists from controller in Rails

How to test if at least one record exists?

Option 1: Using .exists?

Option 2: Using .present? (or .blank? , the opposite of .present? )

Option 3: Variable assignment in the if statement

This option can be considered a code smell by some linters (RuboCop for example).

Option 3b: Variable assignment

You can also use .find_by_user_id(current_user.id) instead of .where(...).first

Best option:

• If you don’t use the Business object(s): Option 1
• If you need to use the Business object(s): Option 3

Alternative Answer:

In this case, you can use the exists? method provided by ActiveRecord:

2. How to ignore lines with comments?

There is a way to ignore cops on a per-line basis.

There is also a way to do it via the configuration file.

Run rubocop --auto-gen-config and it will generate a file that you can use to disable the offenses.

The command also gives a hint on what to do to load those options.

On a line per line basis, you can enable and disable the cops as well.

You can also do more than one rule at a time in your code.

By using an inline directive, the directive becomes valid only for that line, and it would look like this:

It’s possible to define regex patterns to automatically ignore certain lines in rubocop.yml , so you could choose to ignore all lines starting with a # character:

This could be improved so that “indented” comment lines (i.e. whitespace followed by a # character) is also ignored if that’s what you want.

Note that this doesn’t account for lines of code that end with a comment, though:

3. How to split Ruby regex over multiple lines?

You need to use the /x modifier, which enables free-spacing mode.

Like in this case:

Using %r with the x option is the preferred way to do this.

See this example from the GitHub ruby style guide

4. RuboCop: Line is too long ← How to Ignore?

You can disable a bunch of lines like this:

Or add this to your .rubocop.yml file to increase the max length:

Creating a .rubocop.yml file (keep an eye on the initial . in the filename) in the root of your project, you’ll have a bunch of options:

5. What is meant by ‘Assignment Branch Condition Size too high’ and how to fix it?

Assignment Branch Condition (ABC) size is a measurement of the size of a method. It is essentially determined by counting the number of A ssignments, B ranches, and C onditional statements.

To reduce the ABC score, you could move some of those assignments into before_action calls:

6. How to tell RuboCop to ignore a specific directory or file?

You can add the following to .rubocop.yml:

where the path is relative to .rubocop.yml

From rubocop/default.yml :

7. How to integrate RuboCop with Rake?

The simple answer is just adding this to your Rakefile:

As of version 0.10.0 RuboCop contains a custom rake task that you can use. Just put the following in your Rakefile

Make sure to use upper-case ‘R’ and ‘C’ or you will get a NameError.

8. How to silence RuboCop warning on Assignment Branch Condition?

This is the message for the Metrics/AbcSize cop.

# rubocop:disable Metrics/AbcSize

On your RuboCop config

9. How to disable frozen string literal comment checking?

Add the following to your .rubocop.yml :

10. How to pass &:key as an argument to map instead of a block with Ruby?

Pass &:key as an argument to map instead of a block.

11. How to fix "SublimeLinter-RuboCop not running even when enabled and RuboCop in the path"?

First, specify the right path for you ruby env in Packages/User/SublimeLinter.sublime-settings as this:

After that close sublime completely and reopen it.

In Conclusion

These are the most asked questions about the RuboCop. If you have any suggestions or any confusion, please comment below. If you need any help, we will be glad to help you.

We, at Truemark , provide services like web and mobile app development, digital marketing, and website development. So, if you need any help and want to work with us, please feel free to contact us.

Hope this article helped you.

Original Source: DevPostbyTruemark

Top comments (0)

Templates let you quickly answer FAQs or store snippets for re-use.

Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink .

Hide child comments as well

For further actions, you may consider blocking this person and/or reporting abuse

The Vital Role of UI/UX Design Companies in the Digital Era

steve maxwell - Jun 8

Configuring Hibernate for Azure Virtual Desktop (AVD) | Step-by-Step Guide

amalkabraham001 - Jun 8

HackTheBox - Writeup Nunchucks [Retired]

Guilherme Martins - Jun 8

Start Your Cloud Journey in No Time

Mike Tyson of the Cloud - Jun 8

We're a place where coders share, stay up-to-date and grow their careers.

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Setting the default display name for my model

I have a method in my Ruby code that sets the default name for my model. Rubocop complains that Assignment Branch Condition Size is too high, 21.24/15. How can I improve this?

• ruby-on-rails

4 Answers 4

• Conditionals are expressions in Ruby, you can (and, idiomatically, should) move the assignment outside.
• active_record_relation.count == 0 is ok, but active_record_relation.empty? is more declarative.

• \$\begingroup\$ I only set count as for the the first expression because it is being use in the else condition. \$\endgroup\$ –  Antarr Byrd Apr 9, 2015 at 15:45
• 1 \$\begingroup\$ Maybe when should be indented? \$\endgroup\$ –  Caridorc Apr 9, 2015 at 15:46
• 1 \$\begingroup\$ Usually people does not indent it. The ruby-style-guide says no indentation: github.com/bbatsov/ruby-style-guide \$\endgroup\$ –  tokland Apr 9, 2015 at 15:46
• \$\begingroup\$ Thanks, it still complains but this is an improvement. 18.36/15. Rubocop does complain that when should be indented as deep as case. \$\endgroup\$ –  Antarr Byrd Apr 9, 2015 at 15:50
• 1 \$\begingroup\$ Yep, your original code has a bug then. Anyway, updated here. \$\endgroup\$ –  tokland Apr 9, 2015 at 19:21

The method is doing three things:

• Determining whether or not to set display_name .
• Determining the default display name.
• Setting display_name to the default value.

Each of those adds to the Abc metric. The biggest contributor to the Abc metric is determining the default display name. To me, that also seems like the most logically separate. We can lower the Abc metric by extracting that responsibility to its own method.

Extracting default_display_name makes it slightly simpler to test the default display name logic. You could also use that logic elsewhere, e.g., a UI could show the current display name and ask if they want to reset it to the default display name.

At this point, I'd question whether set_default_display_name is necessary or if it could be inlined.

Another option, is to keep your code as is and modify your .rubocop.yml file to increase the threshold of the Abc metric, or disable it entirely. The Abc metric is all about code size, not complexity. Theoretically, bugs increase with code size. You'd have to determine if this low of a threshold makes it easier to mask bugs. (Based on an earlier thread, the answer is probably, "yes", since your original code seems to have a bug. I retained the functionality of your original code in this example.)

--- Addendum ---

@ramonrails makes a good point in the comments. I'm usually fine with return guard clauses at the top of ruby methods. However, I agree that having a return in the middle of this method is not ideal.

This answer was only addressing the ABC question. If this were my code, I'd extract the credentials logic completely from this "view" code.

Something like:

We're far afield from the question at that point though.

• 1 \$\begingroup\$ This solution should be the accepted answer as is way more readable and really follows the spirit of clean code. \$\endgroup\$ –  BooVeMan Nov 11, 2015 at 12:28
• \$\begingroup\$ Abc metric provided the "ah ha!" moment for me. excellent answer \$\endgroup\$ –  Brandt Solovij Apr 8, 2016 at 2:34
• 1 \$\begingroup\$ Two return points in a 3-line code does not seem to be a good ruby practice. \$\endgroup\$ –  Ram on Rails Sep 7, 2016 at 20:32

Unless I'm mistaken, you can flip just the conditional: display_name will be set to name is either of the counts is zero. So that's an OR clause on the counts being zero, rather than an AND clause on the counts being non-zero.

So that plus ||= and a begin..end will let you do:

I'm assuming here, that blank? is checking for nil specifically, so you can use ||= . However, if display_name can be an empty string that won't work. In that case, I'd personally keep the early return you have now.

I don't know what Rubocop will think of either of these solutions, though.

• \$\begingroup\$ .display_name can be an empty string so the early return would likely be best \$\endgroup\$ –  Antarr Byrd Apr 9, 2015 at 19:50

Read the comments in the code for an explanation. This is the code of the selected answer, more optimized/DRY.

update 1 (2016-09-08): Reference code removed from comments. Now the comments explain only the optimizations to the selected answer.

• \$\begingroup\$ You have presented an alternative solution, but haven't reviewed the code. Please explain your reasoning (how your solution works and how it improves upon the original) so that the author can learn from your thought process. \$\endgroup\$ –  Mast ♦ Sep 7, 2016 at 9:04
• \$\begingroup\$ @Mast The comments seem to be embedded in the code here. It's not ideal though. In a way this could be a comment (or multiple) to the existing answer, but right now this is an answer (it's not a very good answer, but it is an answer) \$\endgroup\$ –  Simon Forsberg Sep 7, 2016 at 10:39
• \$\begingroup\$ I'd recommend reducing the number of commented lines in this answer. It has potential, but for now I am definitely downvoting. \$\endgroup\$ –  Simon Forsberg Sep 7, 2016 at 10:40
• \$\begingroup\$ @Mast This is not an alternate solution, just more optimized code for the selected answer. That is why the code from the selected answer is also put in comments as a reference. \$\endgroup\$ –  Ram on Rails Sep 7, 2016 at 20:09
• 1 \$\begingroup\$ I removed my downvote but I would recommend not putting your explanation of changes within the code block. Answers are better that way. \$\endgroup\$ –  Simon Forsberg Sep 7, 2016 at 20:19

Your Answer

Sign up or log in, post as a guest.

Required, but never shown

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .

Not the answer you're looking for? Browse other questions tagged ruby ruby-on-rails or ask your own question .

• The Overflow Blog
• Introducing Staging Ground: The private space to get feedback on questions...

Hot Network Questions

• A phrase that means you are indifferent towards the things you are familiar with?
• How can I obtain a record of my fathers' medals from WW2?
• StreamPlot does not give me the streamlines I ask for
• Sum of square roots (as an algebraic number)
• Estimating Probability Density for Sample
• "Mandatory reservation" on Off-Peak ticket?
• What percentage of light gets scattered by a mirror?
• Quick release inside of thru axle?
• Is it rational for heterosexuals to be proud that they were born heterosexual?
• What terminal did David connect to his IMSAI 8080?
• What scientific evidence there is that keeping cooked meat at room temperature is unsafe past two hours?
• Application of Lie group analysis of PDE (beyond calculation of exact solutions)
• Understanding the Amanda Knox, Guilty Verdict for Slander
• Converting NEMA 10-30 to 14-30 using ground from adjacent 15 amp receptacle
• Are your memories part of you?
• What’s the history behind Rogue’s ability to touch others directly without harmful effects in the comics?
• Why does SQL-Server Management Studio change "Execute Query" into "Save Results"?
• Why does this arc die in the center?
• I'm looking for a series where there was a civilization in the Mediterranean basin, which got destroyed by the Atlantic breaking in
• How to underline several empty lines
• How might a physicist define 'mind' using concepts of physics?
• Recovering a group using tannaka reconstruction
• Python matrix class
• What does "however" mean in this sentence? Does it mean ''still'' or "moreover"?

Navigation Menu

Search code, repositories, users, issues, pull requests..., provide feedback.

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly.

To see all available qualifiers, see our documentation .

• Notifications You must be signed in to change notification settings

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

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

Fix "Rubocop/Metrics/AbcSize" issue in app/models/conversation.rb #62

pranavrajs commented Oct 2, 2019

github-actions bot commented Aug 10, 2022

Sorry, something went wrong.

Successfully merging a pull request may close this issue.

More than 3 years have passed since last update.

RuboCopでこんなエラーが出た。Assignment Branch Condition size for search is too high.

コミットをする前にこんなエラーが出た。 調べてみると、なげーよ、幅取りすぎだろみたいなエラーらしい。

RuboCopとは。簡単に

RuboCopのGithub https://github.com/rubocop-hq/rubocop/tree/v0.28.0

このRubCopはコードを検査してくれるものらしくて、コードが長いとか、インデントが変だとかいろんなことを教えてくれる。勝手に直してくれる（不自然なインデントを修正）ときもあれば、警告文だけだして、自分でどうにかしてくれみたいな時もある。ただ、このRuboCopからの指摘も全てが正しい訳ではないっぽい。

　今回のエラーに関して

最初に述べたように、なげーよ的な意味らしい。

実際に指摘を受けたコード

自分でも書いていて、長いなと思った。縦に長い。ただ、今の知識ではどうやってコードをより簡潔なものにすればいいか思いつかなかった。だれか教えてください。

それで結局どうしたか・・・

.rubocop.yml RuboCopの設定を変更した。 エラー文を見てみると、、、、

[<10, 21, 5> 23.79/20] この部分が、点数を表しているっぽい。これでみると、これだと『MAXスコアが20なのにお前のは23.79だよ』ってことらしく、これをどうにかするしかないと思った。

それで、.rubocop.yml内にある設定を変更した。

どう変更したかというと、、、

このMaxの部分を 25に設定を変更した。そしてコミットすると、RubCopからの指摘を受けずにすんだ。

設定変えられるのかー程度に、この記事では感じていただければ、幸いです。

Register as a new user and use Qiita more conveniently

• You get articles that match your needs
• You can efficiently read back useful information
• You can use dark theme

• Stack Overflow Public questions & answers
• Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers
• Talent Build your employer brand
• Advertising Reach developers & technologists worldwide
• Labs The future of collective knowledge sharing
• About the company

Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Get early access and see previews of new features.

How does "Assignment Branch Condition size for index is too high" work?

Rubocop is always report the error:

app/controllers/account_controller.rb:5:3: C: Assignment Branch Condition size for index is too high. [30.95/24]

How to fix it? Anyone has good idea?

• code-metrics

The ABC size [1] [2] is

computed by counting the number of assignments, branches and conditions for a section of code. The counting rules in the original C++ Report article were specifically for the C, C++ and Java languages.

The previous links details what counts for A, B, and C. ABC size is a scalar magnitude, reminiscent of a triangulated relationship:

Actually, a quick google on the error shows that the first indexed page is the Rubocop docs for the method that renders that message .

Your repo or analysis tool will define a threshold amount when the warning is triggered.

Calculating, if you like self-inflicting....

Your code calcs as

That's a 'blind' calculation with values I've made up ( 1 s). However, you can see that the error states numbers that probably now make sense as your ABC and the threshold:

So cop threshold is 24 and your ABC size is 30.95 . This tells us that the rubocop engine assign different numbers for A, B, and C. As well, different kinds or Assignments (or B or C) could have different values, too. E.G. a 'normal' assignment x = y is perhaps scored lower than a chained assignment x = y = z = r .

tl;dr answer

At this point, you probably have a fairly clear idea of how to reduce your ABC size. If not:

• a simple way it to take the conditional used for your elsif and place it in a helper method.
• since you are assigning an @ variable, and largely calling from one as well, your code uses no encapsulation of memory. Thus, you can move both if and elsif block actions into each their own load_search_users_by_role and load_search_users_by_order methods.

• Thanks for you explanation –  pangpang Jan 9, 2016 at 4:45
• @pangpang You should use a 'bang' ( ! ) at the end of the method name, like I wrote, as this is the ruby convention for when a method mutates data / state as a result of executing. Also, thank you & glad –  New Alexandria Jan 9, 2016 at 5:03
• 3 No, that is not the convention. The convention is that if and only if there are two methods which do the same thing, then the one which is more surprising is named with a bang. This has nothing to do with mutation (see e.g. save vs. save! in ActiveRecord or exit vs. exit! in Ruby) and it only applies when there are two methods (see e.g. about a dozen methods in Array or String or Hash which modify the receiver, yet don't have a bang.) There should only ever be a bang method if there is also a non-bang method with the same name. –  Jörg W Mittag Jan 9, 2016 at 6:32
• @jorgwmittag I see you post lots of good things. I will take you at your word. –  New Alexandria Jan 9, 2016 at 13:23
• 1 c2.com link is broken -- here's another good description: hub.codebeat.co/docs/… –  RubyTuesdayDONO Oct 13, 2016 at 19:10

Your Answer

Reminder: Answers generated by artificial intelligence tools are not allowed on Stack Overflow. Learn more

Sign up or log in

Post as a guest.

Required, but never shown

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .

Not the answer you're looking for? Browse other questions tagged ruby code-metrics rubocop or ask your own question .

• The Overflow Blog
• Introducing Staging Ground: The private space to get feedback on questions...
• Featured on Meta
• The return of Staging Ground to Stack Overflow
• The [tax] tag is being burninated
• The 2024 Developer Survey Is Live
• Policy: Generative AI (e.g., ChatGPT) is banned

Hot Network Questions

• NES Emulator in C
• Build the first 6 letters of an Italian codice fiscale (tax identification number)
• Cannot open an .mbox file with neomutt (although it works with mutt)
• What is the difference in meaning between the two sentences?
• A trigonometric equation: how hard could it be?
• Estimating Probability Density for Sample
• Are your memories part of you?
• What's the maximum amount of material that a puzzle with unique solution can have?
• Death in the saddle
• How to underline several empty lines
• Dispute cancellation fees by 3rd-party airline booking
• In Catholicism, is it OK to join a church in a different neighborhood if I don't like the local one?
• What legal reason, if any, does my bank have to know if I am a dual citizen of the US?
• G string becomes out of tune in F shape barre chords
• My vehicle shut off in traffic and will not turn on
• Can LLMs have intention?
• Converting NEMA 10-30 to 14-30 using ground from adjacent 15 amp receptacle
• Can I paraphrase an conference paper I wrote in my dissertation?
• How can I obtain a record of my fathers' medals from WW2?
• How often does systemd journal collect/read logs from sources
• Handling cases of "potential" ChatGPT-generated reviews in non-anonymous program committees (as a PC member)
• Could a 200m diameter asteroid be put into a graveyard orbit and not be noticed by people on the ground?
• Show this process is Brownian motion
• What percentage of light gets scattered by a mirror?