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Storybook Stories

posthog/storybook-stories

Write Storybook stories for PostHog UI components. Covers the provider stack stories run inside, the key gotcha that tRPC/useHostTRPC queries never resolve in Storybook (so data-fetching components render empty), and the pure-presentational split that makes a component storyable. Use when adding or fixing a *.stories.tsx file under packages/ui.

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on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/PostHog/posthog --skill storybook-stories

The instruction itself

5 sections, as written by the author

Storybook stories in PostHog

Stories live next to components as *.stories.tsx and are collected by

apps/code/.storybook/main.ts (its glob includes

packages/ui/src/**/*.stories.tsx). Run/build:

pnpm --filter code storybook        # dev server on :6006
pnpm --filter code build-storybook  # static build (also a good CI/typecheck gate)

Every story is already wrapped (don't re-wrap)

apps/code/.storybook/preview.tsx applies two global decorators, so a story

should not add its own providers or <Theme>:

  • withAppProviders — a QueryClient, the host tRPC context, a DI

ServiceProvider, and a minimal TanStack Router. So useHostTRPC(),

useService(), useRouterState(), etc. render instead of throwing

"must be used within a Provider".

  • A <Theme> (Radix) bound to the dark/light toolbar global. This root provider is

the one sanctioned Radix usage — it supplies the CSS tokens. Radix *components*

are banned: build stories and components from @posthog/quill plus div +

Tailwind (see UI Components).

Add a per-story decorator only to constrain layout (e.g. wrap in a

maxWidth div so a full-width component sizes realistically).

The gotcha: data never arrives in Storybook

This is the thing that wastes time. In withAppProviders the tRPC ipcLink is

a no-op (apps/code/.storybook/mocks/electron-trpc.ts), so:

  • Any query issued through useHostTRPC() (and hooks built on it, like

useClaudeCliSessions) stays pending foreverquery.data is

undefined, permanently.

  • useService(TOKEN) returns an inert proxy stub for anything not

explicitly bound (service.foo().bar never throws, but calls are no-ops).

Only a few tokens resolve for real: HOST_TRPC_CLIENT (a no-op client with a

handful of stubbed methods), IMPERATIVE_QUERY_CLIENT, DIFF_WORKER_FACTORY.

So a component that fetches its own data renders its empty/loading branch in

Storybook — frequently null. Storying it directly shows nothing.

The fix: split a pure presentational component

Separate the data/wiring from the rendering, and story the pure part — which

also satisfies the repo rule "components render; hooks wrap exactly one query"

(AGENTS.md). Keep both in the same file:

// Pure — takes data + handlers as props. This is what the story targets.
export function WidgetList({ items, onPick }: WidgetListProps) { … }

// Container — does the tRPC/useService wiring, renders <WidgetList/>.
export function Widget({ repoPath }: WidgetProps) {
  const { data } = useSomeQuery(repoPath);
  return <WidgetList items={data?.items ?? []} onPick={…} />;
}

Then each story is just args for WidgetList — one per visual state (empty,

single, over-limit, in-flight/disabled, fallback text, …). Real example:

packages/ui/src/features/task-detail/components/ContinueCliSessions.tsx +

.stories.tsx.

Filtering/branching that lives in the container (not the pure view) isn't

exercised by these visual stories — cover it with a small unit test if it's

worth pinning.

Conventions

  • title groups in the sidebar, e.g. "Task Detail/ContinueCliSessions".
  • Build fixtures with a small factory (session(overrides)) rather than

repeating object literals across stories.

  • Date.now()/new Date() are fine in stories, but fixed ISO strings keep

relative-time output stable enough for visual review.

  • Typecheck covers stories (they're .tsx under the package); a

build-storybook additionally catches Storybook-specific breakage.

How to use it

Copy the folder

Take posthog/storybook-stories from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.