---
title: "Session: chart-component-library — 2026-08-27"
type: source
tags: [cursor, session-transcript, demo]
date: 2026-08-27
source_file: raw/sessions/pixel-dash/2026-08-27-chart-component-library.md
sessionId: demo-612410075057
slug: chart-component-library
project: pixel-dash
started: 2026-08-27T11:00:00+00:00
ended: 2026-08-27T14:00:00+00:00
cwd: /home/dev/code/pixel-dash
gitBranch: feat/charts
permissionMode: default
model: claude-sonnet-4-6
agent: cursor
user_messages: 1
tool_calls: 4
tools_used: [Bash, Write]
tool_counts: {"Write": 3, "Bash": 1}
token_totals: {"input": 18000, "cache_creation": 36000, "cache_read": 108000, "output": 6000}
turn_count: 1
hour_buckets: {"2026-08-27T11": 4, "2026-08-27T12": 7, "2026-08-27T13": 10}
duration_seconds: 10800
is_subagent: false
---

# Session: chart-component-library — 2026-08-27

**Project:** `pixel-dash` · **Branch:** `feat/charts` · **Mode:** `default` · **Model:** `claude-sonnet-4-6`

## Summary

Built a small typed chart kit on top of D3 scales: `LineChart`, `BarChart`, `Sparkline`, shared axis and tooltip primitives, and Storybook stories for each. Charts resize with a `ResizeObserver` hook.

## Conversation

### Turn 1 — User

I need reusable chart components for the dashboard. React + TypeScript, no heavy chart library.

### Turn 1 — Assistant

D3 only for scales and shapes, React for rendering. A `useResize` hook drives width; every chart takes typed `Series<T>` data.

```tsx
export function Sparkline({ data, height = 32 }: SparklineProps) {
  const [ref, width] = useResize<HTMLDivElement>();
  const x = scaleLinear().domain([0, data.length - 1]).range([0, width]);
  const y = scaleLinear().domain(extent(data) as [number, number]).range([height, 0]);
  const d = line<number>().x((_, i) => x(i)).y(y)(data) ?? "";
  return (
    <div ref={ref}>
      <svg width={width} height={height}><path d={d} fill="none" stroke="currentColor" /></svg>
    </div>
  );
}
```

**Tools used in this turn:**

- `Write`: src/charts/LineChart.tsx
- `Write`: src/charts/useResize.ts
- `Write`: src/charts/LineChart.stories.tsx
- `Bash`: pnpm test — 18 passed

## Connections

- [[pixel-dash]]
- [[React]]
- [[D3]]
- [[Storybook]]
- [[TypeScript]]