Python Coverage Visualizer

Know which lines your tests missed — without leaving the editor.

You run pytest. You get 73%. But 27% of what? Finding uncovered lines means opening a browser report, hunting for your file, and mentally mapping line numbers back to your code. Coverage Visualizer cuts all of that — green and red highlights appear inline, right where you write, the moment you run your tests.

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Features

Inline highlights — green line backgrounds for covered lines, red for missed, with overview ruler markers so you can scan an entire file at a glance without scrolling.

CodeLens — a live coverage percentage appears above every def and class as you work. See a function's coverage without opening any report.

Hover tooltips — hover any highlighted line for an instant ✓ Covered or ✗ Not covered message.

Interactive dashboard — an SVG ring chart, overall stats, and a sortable file table. Click any filename to jump straight to it in the editor.

Sidebar tree view — a persistent Coverage panel in the Explorer sidebar shows every file with a pass / warn / fail icon. Always visible, always current.

Status bar — your total coverage percentage sits in the status bar. Click it to open the dashboard.

Auto-reload — file watchers detect changes to your coverage file and refresh all decorations instantly. Run your tests, save — done.

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Supported Formats

Format	How to generate
coverage.json	pytest --cov=. --cov-report=json
coverage.xml	pytest --cov=. --cov-report=xml
.coverage	pytest --cov=. (raw SQLite, no JSON step)

No Python runtime required — the extension reads all three formats natively.

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Installation

Search for Python Coverage Visualizer in the Extensions panel (Cmd+Shift+X / Ctrl+Shift+X) and click Install.

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Quick Start

1. Install pytest-cov in your Python project:

   pip install pytest-cov

2. Run your tests and generate coverage:

   pytest --cov=. --cov-report=json

3. In VS Code, open the Command Palette (Cmd+Shift+P / Ctrl+Shift+P) and run: Coverage Visualizer: Show Coverage

Green and red highlights appear across all open Python files immediately.

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Commands

Command	What it does
Coverage Visualizer: Show Coverage	Load coverage and apply highlights to open files
Coverage Visualizer: Show Dashboard	Open the interactive coverage dashboard
Coverage Visualizer: Clear Coverage	Remove all highlights and reset state

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Configuration

Open Settings (Cmd+,) and search for Coverage Visualizer, or add to settings.json:

Setting	Default	Description
coverageVisualizer.thresholdGood	80	% at or above which a file shows green in the sidebar
coverageVisualizer.thresholdWarn	50	% at or above which a file shows yellow (below → red)
coverageVisualizer.coveredHighlightColor	rgba(0, 180, 0, 0.10)	Background color for covered lines
coverageVisualizer.uncoveredHighlightColor	rgba(220, 50, 50, 0.10)	Background color for uncovered lines
coverageVisualizer.enableCodeLens	true	Show coverage % above def / class definitions
coverageVisualizer.enableHoverMessages	true	Show covered / not-covered tooltip on hover
coverageVisualizer.autoReloadOnChange	true	Auto-reload decorations when coverage files change
coverageVisualizer.coverageJsonPath	coverage.json	Path to coverage.json relative to workspace root