Addon-controls: Warn if docs preset is run after controls

Addon-controls requires addon-docs and also requires that its preset is run earlier in the main.js addons array. We should check for this automatically and warn if its misconfigured because people might not see this in the docs.

[bekapod]

👋 I am running into this warning as well, I am using a self-created preset which looks like: ['@storybook/addon-essentials', '@storybook/addon-a11y'] and my app configuration is just ['my-preset'].

After doing some digging, I see that the checker only ever receives my app configuration rather than the preset config. This means the indexOf’s return -1 rather than >= 0 (because neither controls, docs or essentials is explicitly listed in my app).

I’m not sure what the solution is though 😦 - would it be expected that the checker resolve my-preset to figure out if that’s loading the presets in the correct order?

[shilman]

@benbender it’s a complicated system and we’ll overhaul it at some point soon.

what’s going on is that there’s a whole pipeline of argType inference that happens at startup time. this includes args that the user provides, e.g. args: { a: 3 } => "there’s an arg called a that’s a number. there’s also metadata that’s extracted from the source code of the default.component. and finally, if the user manually specifies argTypes, those take precedence. there are even a few more steps that i’m omitting for clarity.

for historical reasons, addon-docs is responsible for the default.component analysis. this is why we expect that to happen before the controls addon consumes the results. in the next iteration (hopefully in 6.4), that analysis will happen outside of addon-docs, and that weird inter-addon dependency won’t be necessary.