Six steps, the same in both editors. Coverage Studio runs no tests of its own: it reads the report your tools already write and puts it on the code — in VS Code, and in Visual Studio 2022 and 2026 on Community, Professional and Enterprise alike. Each step is also a page inside the editor, with a button for it: the walkthrough in VS Code, Tools → Coverage Studio → Getting Started in Visual Studio.
Not installed yet? Download the build for your editor — Community or Pro for VS Code, or the Visual Studio edition — and come back here; the user guide has the install steps for both. Prefer to try before wiring up your own project? The demo project has a report ready.
Any of the 25 formats will do — LCOV, Cobertura, llvm-cov, OpenCover, coverage.py, Istanbul and the rest. If you have none at hand, the demo project has one for C, C++ (clang and MSVC), C#, Visual Basic, TypeScript, JavaScript and Python.
File → Open Folder, or the workspace file. The Coverage icon appears in the activity bar as soon as the extension is active.
A solution, or a folder (File → Open → Folder, which is how a CMake project is opened). The extension loads with it; View → Other Windows → Coverage is its window.
A report in a usual place — coverage/lcov.info, coverage.xml, coverage-final.json and the other well-known names, or wherever the settings point — is found and loaded by itself. If yours is somewhere else, pick it once and it is remembered.
Command Palette → Fucini Coverage: Load Coverage, or Pick Coverage File to choose one. Run Tests with Coverage recognises vitest, jest, pytest, go, cargo, dotnet, maven, gradle, phpunit and ctest, runs them with coverage on and loads what they write.
Tools → Coverage Studio → Load Coverage File…, once. The Fucini Coverage pane of the Output window says which files were looked for and found. Run your tests as you do; Watch Coverage File reloads when the report changes.
Open a source file. Red is a line that never ran, amber a decision taken only one way. Out of the box only such findings are marked; the heatmap colours every line by how often it ran, and inline hit counts write the number after it.
Toggle Coverage Painting switches the marks on and off; fuciniCoverage.editorGutter.mode chooses uncovered or heatmap, hitCounts.inline the counts. The run is in the Coverage view and in VS Code's own Test Coverage panel too.
Tools → Coverage Studio → Show Coverage in Editor, then Gutter: Heatmap or Show Inline Hit Counts as you like. The same settings apply — the Visual Studio edition reads your .vscode/settings.json.
Jump from one untested place to the next instead of scrolling for red. The line above each function says how much of it ran — and its complexity, CRAP score and MC/DC where the report carries them. A hover on a marked line says which branch was not taken, in words.
Next Uncovered is Alt+N, the previous one Alt+P; Next Partly-Tested Decision goes to the next decision only some of whose arms were taken.
Two-stroke chords after Ctrl+Shift+U: N and P for the next and previous uncovered line, B for the next partly-tested decision — not Alt+N, because in Visual Studio Alt and a letter opens a menu. Change them under Tools → Options → Keyboard.
Every file with its metrics — lines, branches, functions, MC/DC — and one score over all of them: a weighted harmonic mean, which cannot be bought with line coverage alone. The status bar shows that score for the run and for the file you are in; rest the pointer on it for the full card.
The Coverage view in the activity bar: sort, collapse, hide columns, click a file to open it. Show Worst-Covered Files and …Functions list where to start.
View → Other Windows → Coverage is the same tree, with the score in its caption; right-click a row to open it or copy its path. Show Coverage Card opens the status bar's card without a pointer.
Say what is enough: a minimum per metric, or a safety profile that asks 100 % of everything. The card then says COMPLIANT or NON-COMPLIANT against them, and the same thresholds hold in both editors because they are the same settings.
Configure Coverage Compliance opens the settings; Check Coverage Thresholds gives the verdict as a command, for a pre-commit hook or a pipeline.
The gear in the Coverage window's toolbar opens the settings window, which writes this edition's user settings or the folder's .vscode/settings.json, as its Write changes to selector says.
From here: the user guide for everything else — formats, merging, path remapping, the score, the HTML report — and the FAQ for plans and licences. The Visual Studio edition is included with every paid plan; a machine where VS Code is activated needs nothing more, and Tools → Coverage Studio → Licence… takes a subscription code where it is not.