5 JavaScript Static Analysis Tools

With the rise of modern software development practices, the prominence of static analysis has grown. Static code analysis allows developers to improve the codebase's readability and consistency while finding possible bugs and anti-patterns. Static analysis tools help us to validate the modern development standards and assess the quality of the same.

A majority of the software development teams, across the world, have been using static code analysis tools. Static code analysis identifies bad and redundant code and fixes it before it lands in production. With automated static analysis, we don't need to rely on dynamic analysis, where the code gets executed on a processor to identify bugs.

Let's take a look at some of the best JavaScript static analysis tools that you can make use of.

Why Use Static Analysis for JavaScript?

The Javascript ecosystem covering almost every development need has gathered pace for the past few years. With static analysis, we can easily maintain the code quality with little effort.

Bugs and duplicated code is retrieved and fixed, with code insights generated at every stage of development. It allows the developers to keep track of the blockers they might face in the code and possibly fix them, thus eliminating a pain point.

DeepSource

DeepSource is one of the most popular tools for static analysis, providing tracking over 800+ potential issues, like unused variables, empty functions, usage of Script URLs, and more in JavaScript codebase. DeepSource JavaScript analyzer currently supports a wide variety of Javascript libraries and frameworks like ReactJS, VueJS, AngularJS, Angular, Ember, and more, along with various ECMAScript versions and Typescript. If you are following a style guide, DeepSource provides support for that as well, along with the module system.

DeepSource strictly enforces ESLint core JavaScript rules, which allow us to identify bugs, anti-patterns, and non-performant code. 

Some key features of DeepSource include:

• Single file configuration.
• Highlight important metrics like documentation coverage and dependency.
• Auto-fix for common issues.
• Code metrics tracking and reporting.
• Analysis of every pull request and commit.
• Integrated dashboard with issue descriptions.

These features make DeepSource a lucrative choice for static analysis and provide a go-to-option for code analysis. With the analyzers working at file-level and repository-level, you would never have to worry in the future about maintaining your Javascript code.

DeepScan

DeepScan provides automated tracking of issues in the JavaScript codebase through static analysis. DeepScan supports a wide range of Javascript libraries and frameworks like React, Angular, and Vue and banks upon its data-flow analysis to find the code execution flow and issues. It also provides a general grade for the project you are working on to find ideas for improving the codebase quality.

Some key features of DeepScan includes:

• Integrated dashboard for issue tracking.
• Real-Time collaboration with team activity.
• Active analysis over the codebase.
• Usage of control flow graph for code execution.
• Grade calculation through issue density tracking.

DeepScan is an active choice for developers and enterprise Teams for managing their code quality. Their static analysis goes beyond ESLint, providing more coverage and issue tracking, making it a definite choice to identify tricky issues.

LGTM

LGTM states its mission "to promote community-driven security analysis" and has made it possible through automated issue and vulnerability checking. LGTM banks upon CodeQL to drive its issue tracking and finding common bugs that occur across the codebase. LGTM supports an integrated dashboard for real-time analysis, along with issue personalization, to help teams focus on issues that matter to them.

LGTM supports various general-purpose programming languages, with Javascript being prominent. Its issue tracking is prioritized intelligently, which gives it a specific edge over other Static analysis Tools. 

Some key features of LGTM are:

• Provides SemmleQL to write our Code Analysis Queries.
• Commits are checked every day.
• Provides a REST API to integrate with the workflow.
• Provides real-time project alerts and suppression.
• Analyzed over original repositories, not forks.

LGTM banks upon intelligent detection, which is made possible by analyzing different codebases. Thus it highlights an alert if we introduce a new bug or vulnerability. With granular access to a user dashboard, LGTM is a definite go for maintainers looking for a specific holdover code analysis.

SonarCloud

SonarCloud is yet another static analysis tool that aims to champion quality code among software projects. Featuring an IDE extension, named SonarLint, and other features like bug and code smell detection and continuous inspection, SonarCloud is one of the favorite go-to tools. SonarCloud supports several general-purpose programming languages, with Javascript in prominence.

SonarCloud can be integrated with CI Pipelines like GitHub Actions and Azure DevOps, to ensure that bad code never lands in production. 

Some key features of SonarCloud are:

• Access to the project dashboard and the project metrics.
• Features Go/No Go quality Gate while analyzing code.
• Continuous inspection over all major Git providers.
• IDE extension named SonarLint available for better use.
• Supported by TravisCI, GitLabCI, CircleCI, and more.

The tool keeps track of code maintainability, reliability, coverage, and more while aiming to accelerate the reviews from maintainers. With security hotspots as an additional feature, it can provide broader coverage to help developers understand the issues and leaks.

Codacy

Codacy is one of the most popular static analysis tools providing coverage over issues such as code duplication, complexity, and more. Codacy is integrated with ESLint JavaScript linter to provide quick access to potential issues and bugs, on an integrated dashboard.

With Codacy, you can add specific repositories you have access to or have forked, and Codacy starts analyzing your code for bugs and style Issues.

Some key features of Codacy include:

• Automated code reviews and issue tracking.
• Integration with various Git providers.
• Provides code standardization and user management.
• Supported in various workflows and CI integrations.
• Provides self-hosted services as well.

Codacy will re-analyze your source code with every push, which eases code reviews and analysis. With a supporting community, Codacy is gaining large traction among developers for code Reviews and analysis.