Alternate_Formatters.md

Alternate coverage report formatters

The community around SimpleCov provides a whole bunch of alternate formatters beyond the bundled HTML and JSON formatters.

If you have built or found one that is missing here, please send a Pull Request for this document!

Terminal output

simplecov-console

by Chetan Sarva

A simple console output formatter: a table of per-file coverage (branch coverage included) plus the missed lines, right in your terminal.

simplecov-summary

by Boris Staal

Prints a colored per-group coverage summary to the console at the end of a run.

simplecov-stdout

by Lance Ivy

Prints actionable feedback straight to stdout: which of the files you touched are missing coverage, and where.

simplecov-tdd

by Josh Frankel

Coverage feedback tuned for a test-driven workflow: reports on the file under test as you run its spec.

simplecov-teamcity-summary

by Ben Cochez

Reports the coverage summary through TeamCity service messages so it shows up on the build page.

simplecov-t_wada

by Yosuke Kabuto

t_wada AA formatter for SimpleCov

simplecov-single_file_reporter

by Michael Grosser

A formatter that prints the coverage of the file under test when you run a single test file.

simplecov-single_file

by Taras Shpachenko

Single file coverage reports for SimpleCov.

HTML reports

simplecov-tailwindcss

by Chiefpansancolt

A TailwindCSS & TailwindUI Designed HTML formatter with clean and easy search of files with a tabular left Navigation.

simplecov-material

by Chiefpansancolt

A Material Design HTML formatter that is clean and easy to read.

simplecov-hypertext

by Christoph Olszowka, Alan Ridlehoover, and Fito von Zastrow

An HTML formatter built to stay fast and navigable on large codebases.

simplecov_html_inline

by Toby Hsieh

A variant of simplecov-html that inlines its assets, producing a report that survives being passed around as a single CI artifact.

simplecov-inline-html

by Jon Rowe

Inline HTML formatter for SimpleCov.

simplecov-phpunit

by Christian Mayer

A PHPUnit-style HTML report, for those who came to Ruby from PHP and miss it.

Machine-readable formats for CI and tooling

simplecov-cobertura

by Jesse Bowes

A formatter that generates Cobertura XML, consumed by many CI services (GitLab merge-request coverage among them).

simplecov-lcov

by fortissimo1997

lcov formatter for SimpleCov

simplecov_lcov_formatter

by t-mario-y

LCOV formatter positioned as a successor to simplecov-lcov.

undercover

by Jan Grodowski

Warns about methods and blocks a git diff changed that lack test coverage. Its SimpleCov::Formatter::Undercover writes the report data for the separate undercover CLI to read, by default to the same coverage/coverage.json path the bundled formatters own, so whichever formatter runs last decides that file's shape. The bundled simplecov patch command answers the related per-line question (is the code this change touched covered?) without an extra gem.

simplecov-json

by Vicent Llongo

JSON formatter for SimpleCov

simplecov_compact_json

by Coraline Ada Ehmke

A lightweight, summary-level JSON formatter.

simplecov-oj

by Mikael Henriksson

JSON formatter that serializes through Oj, for large projects where the standard JSON dump gets slow.

simplecov-csv

by Fernando Guillen

CSV formatter for SimpleCov

simplecov-rcov

by Fernando Guillen

"The target of this formatter is to cheat on Hudson so I can use the Ruby metrics plugin with SimpleCov."

simplecov-rcov-text

by William "Kina"

Generates the rcov.txt file that metric_fu expects.

simplecov-clover

by Mikko Kokkonen

Generates Clover XML for Atlassian tooling such as Bamboo.

simplecov-markdown

by Alessandro Rodi

A Markdown summary, handy for pasting into pull requests and chat.

simplecov-review

by Karol Bąk

Reports missed lines in a format for review tools like reviewdog, so coverage gaps surface as PR annotations.

simplecov-ai

by Vitalii Lazebnyi

Concise, deterministic Markdown coverage digests tailored for LLMs and autonomous agents.

Coverage badges

simplecov-badge

by Matt Hale

A formatter that generates a coverage badge for use in your project's readme using ImageMagick.

simplecov-small-badge

by Marc Grimme

A formatter that generates a small coverage badge for use in your project's readme using the SVG.

simplecov-formatter-badge

by Shim Won

Generates an SVG coverage badge locally, with no ImageMagick dependency.

simplecov-shields-badge

by Nilton Vasques

Generates a shields.io-style SVG coverage badge.

simplecov_badger

by traels.it

A formatter that uploads your coverage to a server, that will then host a SVG badge of the score. No need to have the badge stored in repository.

Build your own

simplecov-erb

by Kevin Paulisse

Flexible formatter that generates the output from an ERB template — the quickest route to a custom format without writing a formatter class.