# Coverage map

> Real traffic, and which parts the tests cover. Sample data: eight clusters, full refunds 31% with 46 cases, partial + coupon 14% with 0 cases.

- Type 118 · Relationship
- Component: `<CoverageMap>`, the same name as the Figma component
- Install: `npx shadcn add @chartory/coverage-map` (Code and Complete plans)
- Type page: https://usechartory.com/charts/coverage-map

## Installation

1. **Set up the registry once.** Your token in .env and @chartory in components.json. Skip this when another chart is already installed. [Installation guide](https://usechartory.com/docs/installation)

2. **Add the chart.** One command adds the Coverage map component to your project.

```bash
npx shadcn add @chartory/coverage-map
```

3. **Use it.** Pass your rows. The props are the Figma properties.

usage.tsx:

```tsx
import { CoverageMap }
  from "@/components/chartory/coverage-map"

<CoverageMap
  data={goldenCoverage}
  size="m"
  legend
/>
```

## Props

### `<CoverageMap>`

Every prop but data is a Figma property with the same name and values.

| Prop | Type | Default | Note |
| --- | --- | --- | --- |
| data | CoverageMapData | Required | The chart's data. The tables below list every field. |
| size | "xs" \| "s" \| "m" \| "l" | "m" | The size class. Each one is laid out again from the data. |
| legend | boolean | true | Shows the legend row under the plot. |
| color | "cat-1" \| "cat-2" \| "cat-3" \| "cat-4" | "cat-1" | The data colour of the primary marks (data/primary). |

### CoverageMapData

The data prop: one object for the whole chart.

| Prop | Type | Default | Note |
| --- | --- | --- | --- |
| clusters | CoverageMapCluster[] | Required | One entry per cluster. |

### CoverageMapCluster

One object per entry in clusters.

| Prop | Type | Default | Note |
| --- | --- | --- | --- |
| label | string | Required | The name shown on the chart. |
| x | number | Required | The x value. |
| y | number | Required | The y value. |
| traffic | number | Required | The traffic. |
| cases | number | Required | The test cases. |
| gap? | boolean | false | Marks the cluster as a coverage gap. |

## Coverage map: a React and Figma chart in four sizes

### What does a coverage map show?

A coverage map draws production traffic as clusters sized by share and marks the test cases inside each, so clusters with no tests show as empty. Use it to check a golden set against real use.

Chartory ships it as a Figma component and a React component with the same name. The code installs from the shadcn registry with one command and lands in your project as a file you own.

### What is the Coverage map component?

It is one **<CoverageMap>** component. Its props are the Figma properties with the same names and values, and the props table above lists them. The data is a traffic share and a case count per cluster.

Sizes **XS**, **S**, **M** and **L** re-lay the chart out from the data instead of scaling it, so labels stay readable at every size.

### When should I use it?

- **Is coverage by cluster the point?** Yes means the coverage map fits.
- **Are there test cases?** Yes means the coverage map fits.
- **Is it clusters of real use?** Yes means the coverage map fits.

### When does another type fit better?

- **Two shares side by side.** Use Traffic vs set instead.
- **Traffic only.** Use Treemap instead.
- **Clusters of tickets.** Use Cluster map instead.

## Coverage map questions

### Does the Coverage map chart work with shadcn/ui?

Yes. It installs through the shadcn registry with the shadcn CLI, and the file lands in your project.

### How do I install it?

Add your token and the @chartory registry once, then run npx shadcn add @chartory/coverage-map. The Installation guide has the steps.

### Can my coding agent install it?

Yes. Connect the Chartory MCP server and ask for the coverage map chart; the agent runs the same command and you review the diff.

### What data does it expect?

A traffic share and a case count per cluster. The sample data comes with the component, and the props table lists every field.

### Which sizes does it ship in?

XS, S, M and L, in Figma and in code. Each size is laid out again from the data, so text and lines keep their size.

### Is it in the Figma file too?

Yes. chart/118-coverage-map has the same properties as the component.

### Does it follow light and dark mode?

Yes. Every paint is a token, so the chart follows light and dark mode and the collection you pick.

### Which plan has the code?

Code and Complete. Figma has the Figma file only.