prefer-storybook-6-minor-performance-milestone

What it flags

Flags workflows that visibly run build-storybook or storybook build when the repository depends on Storybook 6.0, 6.1, 6.2, 6.3, or 6.4.

The rule recommends 6.5.x as the first target because some teams cannot jump major versions immediately, while 6.5 concentrates the most CI-relevant Storybook 6.x build improvements.

Why it matters

Storybook 6.x had several performance-relevant minor releases.

• 6.1: startup and story-loading path improvements
• 6.2: Story Store v6 and more efficient story management
• 6.3: CSF optimization and reduced Docs and Controls rerendering
• 6.4: public Storybook code splitting and further Docs/Canvas separation
• 6.5: Webpack 5 support, filesystem cache support, lazy compilation support, and an experimental Vite builder path

For repositories still pinned to early 6.x, moving to 6.5.x can be a smaller compatibility step than a major-version migration while targeting the highest-value 6.x CI build path.

Current heuristic

The rule requires both:

• a detectable Storybook dependency in root package.json
• a workflow job that visibly runs build-storybook or storybook build

It does not flag Storybook 6.5 or newer.

When to ignore it

Ignore this finding when:

• the project is intentionally pinned below 6.5 for compatibility reasons
• the visible workflow job does not represent a meaningful production Storybook build
• the team is already planning a validated major-version migration instead

Suggested verification

• Compare build-storybook wall-clock time before and after the upgrade
• Check output size, Webpack filesystem cache behavior, and peak memory when logs make that visible
• Keep the change only if the runtime gain and compatibility profile are acceptable

Sources

• https://storybook.js.org/blog/storybook-6-1/
• https://storybook.js.org/blog/storybook-6-2/
• https://storybook.js.org/blog/storybook-6-3/
• https://storybook.js.org/blog/storybook-6-4/
• https://storybook.js.org/blog/storybook-6-5/