Allow expo start --dev-client in managed projects

[fson]

Why

It should be possible to use dev client with a managed project.

How

• Removed the "can only be used in bare workflow apps" warning
• Added a check to look up the schema in app.json/app.config.*s when there are no native project (managed project)
• Added a prompt for schema when it's not configured.
• Prompt has a good default.

Test Plan

Created a managed project and verified that expo start --dev-client started the dev server. Tested with:

• app.json including a schema -> started without warnings
• no scheme -> error

Also set the scheme property in app.json to the URI scheme of an app that I had previously built and installed on my Android device. Running expod start --dev-client and pressing a opened the app.

[linear]

ENG-1130 managed support for expo start --dev-client

Option --dev-client can only be used in bare workflow apps. Run expo eject and try again

We should detect the scheme (and direct the user to add a scheme if missing) based on https://docs.expo.io/versions/latest/config/app/#scheme

[EvanBacon]

Maybe a bit more like this

expo-cli/packages/expo-cli/src/commands/utils/modifyConfigAsync.ts

Lines 30 to 51 in 8b73a07

	export async function attemptAddingPluginsAsync(
	projectRoot: string,
	exp: Pick<ExpoConfig, 'plugins'>,
	plugins: string[]
	): Promise<void> {
	if (!plugins.length) return;
	const edits = {
	plugins: (exp.plugins || []).concat(plugins),
	};
	const modification = await modifyConfigAsync(projectRoot, edits, {
	skipSDKVersionRequirement: true,
	});
	if (modification.type === 'success') {
	Log.log(`\u203A Added config plugins: ${plugins.join(', ')}`);
	} else {
	const exactEdits = {
	plugins,
	};
	warnAboutConfigAndThrow(modification.type, modification.message!, exactEdits);
	}
	}

[EvanBacon]

this would just ignore the dynamic config and create a potentially unused file

[fson]

Existing dynamic config is handled by an earlier if – see https://github.com/expo/expo-cli/pull/3523/files#diff-ef67bc980d05133cc7b87b450cf4a04e1546cae27683bc12a749a925bb79cf09R105

If we land in this else branch it means there's no config (dynamic or static) at all so we just create an app.json.

[brentvatne]

if in a managed app we run expo start --dev-client, then prompt the user to add a scheme and update it and launch the server, we will start the dev client server with a scheme that doesn't exist in an dev client build that was created prior to running that command 😮

maybe we can modify the config plugin to add a deterministic scheme derived from the project slug, and use that for expo start --dev-client? we could alternatively depend on the bundle id / package name being added to scheme -- run expo config --type introspect and notice that the bundled id / package names are added to schemes.

[fson]

That's a good point from @brentvatne. I have now removed the prompt for scheme and instead added autogeneration of schemes in the expo-dev-client config plugin here: expo/expo#13147

I'll add support for the autogenerated schemes to the CLI in a separate pull request.