Fucini Coverage Studio for Visual Studio

Reads the coverage file your build already wrote and paints it on the code. Visual Studio 2022 and 2026 — Community, Professional and Enterprise alike.

Your build, your CI job or your target already writes a coverage report: lcov, llvm-cov, gcov, Cobertura, JaCoCo, OpenCover, coverlet, TRACE32 — 25 formats. This extension opens it and shows you, in the editor, what your tests never ran. It does not use Visual Studio's own code coverage, which on Visual Studio 2022 is Enterprise-only: on Community and Professional it is the only coverage the IDE will show, and on Enterprise it reads the reports Visual Studio's own tool cannot.

It is the Visual Studio edition of Coverage Studio for VS Code: the same reader, so the same report gives the same numbers, to the digit, in both editors, and the same fuciniCoverage.* settings, read from .vscode/settings.json.

The coverage on the code, with the Coverage window beside it

In the editor

A margin bar per line — red never ran, amber partly, or a heatmap by visit count.
Inline hit counts — ×12 after the line.
A line above each function with its coverage, branches, complexity, CRAP score and MC/DC, beside Visual Studio's own CodeLens.
Stripes on the scroll bar for every uncovered and partly covered line.
A hover that says which branch was not taken and which condition was never shown to matter, in words.
A dot on a line you have edited since the report was written.
Next and Previous Uncovered, and the next partly-tested decision, as two-stroke chords under Ctrl+Shift+U.

The Coverage window

Under View → Other Windows → Coverage: every file with its lines, branches, functions, MC/DC and CRAP score, one score over all of them, sortable, the files no test loaded listed beneath as unmeasured. A menu on each row opens the file or its folder and copies its path. The status bar carries the run's score and the open file's, each opening the full card.

The Coverage window's toolbar

What it reads

lcov, llvm-cov, gcov and gcovr, Cobertura, JaCoCo, Istanbul, Clover, OpenCover and coverlet, coverage.py, SimpleCov, Go, GNATcoverage, BullseyeCoverage, Testwell CTC++, VectorCAST, TRACE32, xccov, Coveralls, SonarQube generic, EMMA, NCover, dotCover, UCIS and Visual Studio's own .coveragexml — gzipped or not, several at once, merged. Lines, branches, conditions, functions and MC/DC are counted; PIT and Stryker mutation reports are read mutant by mutant.

Whatever wrote the file: C, C++, C#, Visual Basic, Java, Python, Go, Rust, Swift, Objective-C, Ada, PHP, Ruby, JavaScript and TypeScript.

Settings, in 18 languages

The gear in the Coverage window's toolbar opens every setting, grouped and explained, written to this edition's user settings or the folder's .vscode/settings.json — the file VS Code reads too. Getting Started under Tools → Coverage Studio walks the six steps from a report to the lines nobody tests, and opens by itself the first time.

Licence

Included with every paid Coverage Studio plan — Pro, Pro Plus, Business and Enterprise — and covered by a 7-day pass for its week. A machine where Coverage Studio for VS Code is activated needs nothing more: the key is found by itself. Anywhere else, Tools → Coverage Studio → Licence… takes the subscription code from your activation e-mail. There is no free tier in Visual Studio; without a subscription no coverage is read.

Plans and prices: https://fucini.software/coverage-studio/pricing.html

Not yet in this edition

Run Tests with Coverage and the Test Coverage panel are VS Code APIs, and Solution Explorer cannot show badges. The annotated source view, the HTML report and the exports, threshold checks, Error List entries, history and diff coverage follow in the order subscribers ask for them.

Fucini Coverage Studio

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