How to reduce cognitive complexity of a function? . How to reduce cognitive complexity of nested if - JavaScript PDF COGNITIVE COMPLEXITY - SonarSource So we have the response from SonarQube: "Refactor this function to reduce its Cognitive Complexity from 26 to the 15 allowed." Cognitive Complexity is a measure of how hard the control flow of a function is to understand. Reducing Complexity with Guard Clauses in PHP and JavaScript But, we can simplify this code even further by removing else if and else. Code with a traditional if/else \$\begingroup\$ To make code more readable, a good 1st step is to assign names to your conditions. For Java8 use below code, It will help to avoid cognitive and cyclomatic complexity. Finally there is always something to be said about keeping a low cyclomatic complexity. I'm wondering if I can lower the cognitive complexity? Add a comment. What this means is to keep the number of conditional branches as low as possible. That change will reduce Cyclomatic Responsibility and improve maintainability for your code. Both metrics (cyclic and cognitive) can be reduced not by reducing complexity, but by tricking the parser into thinking the code is less complex. Increment the score again for control structure breaks with each level of nesting. javascript - How to refactor and reduce complexity of this code - Code - In this tutorial, we'll walk through the various ways of replacing nested if statements. Tip #2 - IF Expressions. Cognitive complexity reduce issue - The web development company For Cognitive Complexity, the measuring algorithm would be slightly different, Cognitive Complexity is a metric developed by SonarSource, the makers of a code quality tool we use at AWH called SonarQube. Simplify if else conditions to reduce cognitive complexity in Java Cognitive Complexity int sumOfPrimes(int max) But we land up in coding a huge number of nested if statements which make our code more complex and difficult to maintain. We can also move the nest conditions to a separate function. SonarQube Cognitive Complexity - Medium The web development company This is a type ifif code. Readable code understand Cognitive Complexity - Medium In our quest to reduce the cost of maintaining code we are going to keep some goals in mind: Reduce complexity whenever possible by introducing guard clauses; Make the main purpose of the method the most obvious execution path; Think about writing for growth to minimize future complexity; Go forth and make great things! 0. While Cognitive Complexity offers a "discount" for like operators relative to Cyclomatic Complexity, it does increment for all sequences of binary boolean operators such as those in variable assignments, method invocations, and return statements. Thus the following will likely get a lesser score than your original. A good 2nd step would be to notice that most if-statements contain this.isFocused so pull that up into its own if-statement. The cognitive complexity of a function increases if: There are multiple nested structures (like "if else" conditions) If there is flow-breaking code (like "for" loops) The cognitive complexity of JavaScript/TypeScript can be assessed using the SonarLint extension in Visual Studio Code. . Each additional branch will not only add indentation and hurt readability, but will more importantly increase the number of things you have to keep track of. Add exception to Cognitive Complexity for React functional - GitHub Right now this is a score of 4. Reducing Cyclomatic Complexity and NPath Complexity: Steps - Axelerant A method's cognitive complexity is based on a few simple rules: Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one Code is considered more complex for each "break in the linear flow of the code" Code is considered more complex when "flow breaking structures are nested" In JavaScript /react a class component is just a faux name space for a function. The cognitive complexity of a function increases if: There are multiple nested structures (like "if else" conditions) If there is flow-breaking code (like "for" loops) The cognitive complexity of JavaScript/TypeScript can be assessed using the SonarLint extension in Visual Studio Code. Decision constructs are a vital part of any programming language. Cognitive Complexity Vs Cyclomatic Complexity - An Example With C# Refactoring Using Cognitive Complexity -- moscardino.net Hardique Dasore - Medium So, if you want to . 0. Use small . So, the code can be executed in 4 (2 * 2) times, which means the NPath complexity of the code is four. It is measured at every point that I highlighted using the RED-tangle below. 11 1 function doSomething2() {} 2 3 if (A && B) { 4 5 } else if (B) { 6 7 There are two if/else statements, each giving two path options. It's on the same chord as omitting redundant this qualifiers (Java, C++, C#) and omitting parenthesises in return statements, and so on. else if, else increment nesting level Nested method / lambda increments nesting level. Functions with high Cognitive Complexity will be difficult to maintain. Let's explore different options how we can simplify the code. 2. Cognitive Complexity Introduced Dec. 2016 Available as a rule in SonarQube analyzers . npx elm-review --template jfmengels/elm-review-cognitive-complexity/example --rules CognitiveComplexity. For these purposes, we'll assume this is code in an existing system and we'll look at refactoring it to reduce complexity and make it easier for a programmer to understand. Cyclomatic Complexity Makes Code Harder to Test. Functions by definition are great for reducing cognitive complexity, so all I did was handle the double do something 2 using a function. Recursion Unlike Cyclomatic Complexity, Cognitive Complexity adds a fundamental increment for each Original code. Value assignment with if-else Despite the simplicity, it's awful. Move repeated Code/nested if else to a separate function In order to simplify nest if else conditions, we can move the repeated code to a separate function. 3 Tips To Reduce Cyclomatic Complexity In C# - C# Corner As per some content, I found that maximum value for it is 15 . How to Replace Many if Statements in Java | Baeldung Writing good code: how to reduce the cognitive load of your code How to Reduce Cyclomatic Complexity: A Complete Guide The types of issues that SonarQube can . Consider the code below. First off, If-Else is easily replaced with a switch here. Different Ways to Replace If/Else Statements | The Startup - Medium Refactoring Using Cognitive Complexity | by AWH | Dev Genius - Medium Cognitive Complexity - Code Climate Measuring cognitive complexity with elm-review | jfmengels' blog public void pushDocument (ESDocumentType esDocumentType, Object data, String documentId, long userId, long organizationId) { EnumMap<ESDocumentType, Boolean> docType = new EnumMap<> (ESDocumentType.class); docType.put (ESDocumentType . Basically, you should be writing so many test cases to test this function and have 100% code coverage. Still it's possible to have if statements or something else which would make top level function considered by the rule. An easy way to do that is by running the following command in your Elm project. Reduce IF expressions in your code. For example: this.selectedItemIndex === null || this.selectedItemIndex < 0 might become hasNothingSelected a better name might include context for what this is. SonarQube hooks into a CI pipeline for a project and performs code quality analysis on it. The higher the cognitive complexity of a piece of code, the harder it is to navigate and maintain. The first example will be trivial enough to easily understand, but we'll build on it in the final examples. How to Refactor Your Complex Nested 'if-else' Code? How to reduce cognitive complexity of a function? As we've already mentioned, higher values of cyclomatic complexity result in the need for a higher number of test cases to comprehensively test a block of codee.g., a function. Code with Traditional If/Else Fig 1. Reducing Complexity with Guard Clauses in PHP and JavaScript The Cyclomatic Complexity of the above function is 7. Breaks in Control Structure Ways to reduce the Cognitive Complexity 1. Let's break those down some more. Cognitive Complexity the New Option for Measuring Understandability. Cognitive Complexity Which in my book is a dumber version of cyclic complexity. Cognitive complexity is considered a measure for readable code, It is the entity by which we can decide is our code is readable or not. javascript - How to reduce the Cognitive Complexity of this code based PDF Refactoring with Cognitive Complexity: The New Option for Measuring Use the Single Responsibility principle for extracting a piece of code to other methods and make the method for just one responsibility. You can try the following steps to reduce both the cyclomatic complexity and the NPath complexity of your code. Yes, there is an increase in complexity because the else clause is redundant. You might think that the complexity of this code would increase linearly with the number of if, but it doesn't. We know that functions deal with data and each if generally has logic to deal with the data. Reducing Cyclomatic Complexity. This is similar to @GuerricP original answer, but handles the multiple case of do somthing 2 eg. The threshold chosen by this configuration is set at 15 by default, but if you add the rule to your configuration, you would be able to set it to any other value . I believe cognitive complexity is how the human brain sees it as been complex, I believe your original answer was nearly there, and is the reason I quoted your original answer in mine. It keeps the flow of control growing inside a single function by nesting if from top to bottom. coding style - Do else blocks increase code complexity? - Software Currently, cognitive complexity of such component would be 7, while the equivalent component using class syntax will have only one. Here are the basic rules for calculating a Cognitive Complexity score: Increment the score for every break in the control structure of the code. javascript - How to reduce cognitive complexity of nested if - Stack Ignore shorthand constructs that aid readability. It's thus better to leave out to keep the code lean and mean. Cognitive complexity reduce issue i made a login system with JavaScript for a game idea i had, but apparently my ide says it is too complex, do i need to split one function in more pieces? One measure for determining what is in need of some refactoring is Cognitive Complexity. In order to reduce the cognitive complexity of a Answer I would say the best way to lower the cognitive complexity is to use functions.