CovSight for VS Code

CovSight is a Visual Studio Code extension for viewing functional and code coverage data from simulation databases. It is part of the CovSight ecosystem — a set of open-source tools for coverage-driven verification.

Features

🗄️ Coverage Hierarchy — Browse covergroups, coverpoints, crosses, toggle signals, branches, FSMs, and assertion monitors in a tree view
📊 Coverage Dashboard — Overall summary bar, per-type breakdown table, and uncovered hotspots
🖊️ Inline Source Annotations — Toggle coverage displayed as gutter decorations; file coverage published to VS Code's Testing panel
📋 Testplan Integration — Load .testplan YAML files; see goal/testpoint status linked to live coverage data
✅ YAML IntelliSense — Full schema validation and autocomplete for .testplan files (requires YAML by Red Hat)
🔍 Workspace Discovery — Automatically detects .cdb files in the workspace

Requirements

VS Code ≥ 1.88
Recommended: YAML by Red Hat for testplan IntelliSense

Getting Started

Open your workspace containing one or more .cdb files. CovSight discovers them automatically.
Click a database in the Coverage Databases panel to activate it — the Coverage Hierarchy populates.
Open a testplan with CovSight: Open Testplan to see goal and testpoint coverage in the Testplan panel.

Run the CovSight: Getting Started walkthrough (Help › Walkthroughs) for a guided introduction.

Coverage Hierarchy

The Coverage Hierarchy panel (Explorer sidebar) shows the full scope tree.

Icon Legend

Icon	Scope Type
`package`	Instance / Module
`graph`	Covergroup / Coverinstance
`graph-line`	Coverpoint
`symbol-structure`	Cross coverage
`symbol-boolean`	Toggle signal
`git-branch`	Branch / Condition / Expression
`symbol-enum`	FSM states / transitions

Each node shows a coverage percentage (covered bins / total bins). The icon color reflects status: green = met, orange = partial, red = none.

Filter Commands

Command	Description
`CovSight: Show All Items`	Clear filter — show everything
`CovSight: Show Uncovered Items`	Show only scopes below the coverage goal
`CovSight: Show Covered Items`	Show only fully-covered scopes

Source Annotations

CovSight publishes file coverage to VS Code's built-in Testing panel. Open any source file that appears in the database — coverage is shown in the editor gutter and summary bar.

For toggle signals, CovSight adds gutter decorations color-coded by direction:

🟢 Both 0→1 and 1→0 transitions hit
🟡 Only one direction hit
🔴 Neither direction hit

Toggle decorations are toggled with CovSight: Toggle Source Decorations (default off).

Testplan

A CovSight testplan is a YAML file with extension .testplan (or *testplan*.yaml).

Structure

name: My Block Verification Plan
description: Coverage plan for the AXI controller block

goals:
  - name: Reset Behavior
    description: All reset scenarios exercised
    testpoints:
      - name: TP_POR_Reset
        status: complete
        priority: high
        coverage:
          - type: covergroup
            path: top.dut.reset_cg

testpoints:
  - name: TP_Idle_Timeout
    status: planned
    coverage:
      - type: coverpoint
        path: top.dut.timeout_cp

Coverage Binding Types

Type	Description
`covergroup`	Entire covergroup scope
`coverpoint`	Specific coverpoint
`cross`	Cross coverage point
`assertion`	SVA assertion
`toggle`	Signal toggle scope
`line`	Statement/line coverage
`branch`	Branch or condition coverage

Paths support * as a wildcard for a single scope segment (e.g. top.*.reset_cg).

Testpoint Status

Status	Meaning
`planned`	Not yet started
`in_progress`	Work underway
`complete`	Objectives met
`waived`	Will not be implemented

Dashboard

Open the Coverage Dashboard from the Coverage Hierarchy toolbar or with CovSight: Show Coverage Dashboard.

Sections:

Overall Coverage — progress bar vs. covsight.coverageGoal
By Type — coverage percentage per scope type
Hotspots — lowest-hit uncovered bins (most actionable gaps)
Testplan Closure — per-testpoint coverage percentage (when a testplan is loaded)

Configuration

Setting	Type	Default	Description
`covsight.autoDetect`	boolean	`true`	Auto-discover `.cdb` files on workspace open
`covsight.filePatterns`	string[]	`["*/.cdb"]`	Glob patterns for database discovery
`covsight.coverageGoal`	number	`100`	Target coverage percentage (0–100)
`covsight.warningThreshold`	number	`80`	Percentage below which items show a warning
`covsight.excludeIgnoredBins`	boolean	`true`	Exclude `IGNOREBIN` from calculations
`covsight.excludeIllegalBins`	boolean	`true`	Exclude `ILLEGALBIN` from calculations
`covsight.defaultFilter`	string	`"all"`	Default tree filter: `all`, `covered`, or `uncovered`
`covsight.pathMappings`	object	`{}`	Map database source paths to workspace paths
`covsight.showDecorations`	boolean	`false`	Enable toggle decorations by default

Path Mappings

If your .cdb file was produced on a different machine or with different absolute paths, use covsight.pathMappings to remap them:

"covsight.pathMappings": {
  "/ci/build/rtl/": "/home/me/projects/myblock/rtl/"
}

The longest matching prefix wins. Paths that do not match any mapping are passed through unchanged.

Recommended Extensions

YAML by Red Hat — provides IntelliSense, hover documentation, and validation for .testplan files using the bundled JSON schema.

Known Limitations

Single active database — only one .cdb can be active at a time; multi-database merge is not yet supported.
No write support — CovSight is read-only; it cannot modify coverage data.
Toggle decorations require source paths — the database must contain file path information for inline annotations to work.