Complexity

Simple algorithms for checking basic properties of code complexity.

Two design patterns are implemented here:

• A Builder pattern, which is used to build up state and then finally emit.
• A Visitor pattern, which is used to abstract the process of visiting a data structure such as abstract syntax tree (AST). The only input to be provided is what action to perform at each node.

Esprima

The esprima library is used to parse code and create a static analyzer for basic code complexity metrics.

Instructions

This repository contains a stub that parses a javascript file and visits each function.

1. Run the program and print all the tokens in an ast.

      npm install
      node analysis.js 
   

2. The following calculations are done using one or more visitors (Visitor Pattern):

   • String Usage: How many string literals are used in file? (FileBuilder)

   • ParameterCount: The number of parameters for functions (FunctionBuilder)

   • PackageComplexity: The number of imports used in file.

   • Returns: The number of return statements in function.

   • AllConditions: The total number of conditions in file.

   • SimpleCyclomaticComplexity: The number of if statements/loops + 1.

   • MaxMessageChains: The max length of a message chain in a function. A message chain can be formed from a method call (), a data access (.), or array access [0].

     For example,

     // Message Chain: 4
     mints.name.toString().split(".")[0];
     

   • MaxConditions: The max number of conditions inside one if statement per function.

   • MaxNestingDepth: The max depth of scopes (nested ifs, loops, etc) per function.