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es-analysis/plato

★ 4,558JavaScriptAudience · developerComplexity · 2/5LicenseSetup · easy

TLDR

A command-line tool that scans JavaScript source files and produces an HTML report showing code complexity, lines of code, and lint warnings per file, so you can spot which parts of a codebase are getting hard to maintain.

Mindmap

mindmap
  root((Plato))
    What it does
      Complexity report
      Lint warnings
      Lines of code
    Output
      HTML report
      Visual browser view
    Who it is for
      JavaScript developers
      Tech leads
    Tech stack
      Node.js
      JavaScript
      JSHint or ESLint
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Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

Things people build with this

USE CASE 1

Generate an HTML complexity report for a JavaScript project to identify which files have the highest cyclomatic complexity and are most at risk for bugs.

USE CASE 2

Add Plato to a build script to produce a code health report on each pull request, tracking how complexity changes over time.

USE CASE 3

Use the programming interface to call Plato from within a Node.js task runner like Gulp and integrate the metrics into a custom reporting pipeline.

Tech stack

JavaScriptNode.js

Getting it running

Difficulty · easy Time to first run · 5min

Project currently lacks an active maintainer, so support for newer JavaScript features may be incomplete.

MIT, use freely for any purpose, including commercial, as long as you keep the copyright notice.

In plain English

Plato is a command-line tool that reads JavaScript source code and generates a visual HTML report showing how complex and maintainable the code is. It is aimed at developers who want a quick overview of the health of a JavaScript project, especially as codebases grow larger over time. The report it produces is a website you open in a browser. It shows metrics like cyclomatic complexity (a measure of how many different paths exist through a piece of code), lines of code per file, and lint warnings (style or error-prone pattern alerts caught by tools like JSHint or ESLint). The README links to example reports generated from popular open-source projects like jQuery and Hapi, so you can see what the output looks like before running it on your own code. Installing it takes one command via npm, the standard JavaScript package manager. You then point it at your source files and give it an output folder, and it generates the report there. It can scan directories recursively, exclude files matching a pattern, and accept a lint configuration file so warnings match your existing project rules. There is also a programming interface if you want to call it from within your own build scripts rather than the command line. The README notes that the project currently lacks an active maintainer, meaning it is not under regular development. It was last updated to support ES6 (a modern version of JavaScript) through a community contribution, but future updates depend on someone stepping up to maintain it. The code is open source under the MIT license.

Copy-paste prompts

Prompt 1
I want to run Plato on my Node.js project to see which files have the highest complexity score. Show me how to install it globally and point it at my src/ folder.
Prompt 2
Show me how to call Plato from a Gulp build task so it generates a fresh complexity report in a reports/ folder every time I run the build.
Prompt 3
I want to use a custom ESLint config with Plato so the lint warnings in the report match my project's existing rules. How do I pass my .eslintrc to the Plato command?
Prompt 4
Explain what cyclomatic complexity means in the context of a Plato report and give me a rule of thumb for when a score is high enough to refactor.
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