What is the use of the commons chunk given that we have the dynamically generated shared chunks?

[b4stien]

In its Webpack config Gatsby specifies a commons chunk where it puts every module that is used by every pages/templates. The specific config is: https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/src/utils/webpack.config.js#L598-L603.

In addition there is also shared chunks which dynamically regroups every module used by at least two pages/templates. The config is: https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/src/utils/webpack.config.js#L605-L620.

Hence the question: why do we need both? Isn't the commons chunk a special case of a shared chunk which concerns every pages/templates? Is there something I don't understand and which explains the special case?

[LekoArts]

commons is when it's used in all components, shared is when it's used in at least 2 components but not in all components. So yeah, you could say it's a special case. The PR adding it (with explanation) is here: #22253