[RSDK-9620] implement discover service

[JohnN193]

Initial implementation of the discover service in Go. Currently working on GetModelsFromModules in a separate branch to make it easier on reviewers

ticket: https://viam.atlassian.net/browse/RSDK-9620

[JohnN193]

will revert once api is merged

[JohnN193]

since this is literally copy/paste from the generic service I should probably remove this test, but I'm also fine with leaving it in case we are worried this will somehow break

[randhid]

It is good to test all APIs of a service to ensure that there is adequate coverage. I can't imagine it breaking - but say someone with no context joins viam in the future and removes the DoCommands accidentally - good to have all these tests fail :) . It does not have to be separate from your other test, you can add an injected DoCommand to the injected service in your test.

Good test to have with DoComamnd are: 1. test that it returns errors if no DoCommand is implemented with resource.Named, and 2. responds with the expected responses when a DoCommand is implemented.

[JohnN193]

yeah I just copied the testing structure that other services had, which is why it was separate. Moved all tests into the same test function based on feedback.

[JohnN193]

this is the same function as in proto_conversion_test.go

unsure if theres a good spot to put this function to use it in both spots, or if its fine to leave here

[randhid]

Looks good with a few nits. I think we use pointers when we want to return structs very fast, check with Nick S if that return type should be changed to just an array of resource.Configs rather than an array of pointers.

[randhid]

A few nits - almost there!

[randhid]

@jr22, heads up, we're adding nolints* here to unblock John's pr so the linter doesn't yell at uss - I see the API pr deprecating these constants was merged yesterday https://github.com/viamrobotics/api/pull/612/files

[randhid]

Move this above line 64 so it's closer to where it's populated.

[randhid]

I like this organization better because the working service and failing service functions are grouped together - but if you like yours please feel free to leave as is and resolve this comment. Very minor point here as this is a test.

Suggested change

	workingDiscovery := &inject.DiscoveryService{}
	failingDiscovery := &inject.DiscoveryService{}
	testComponents := []resource.Config{createTestComponent("component-1"), createTestComponent("component-2")}
	workingDiscovery.DiscoverResourcesFunc = func(ctx context.Context, extra map[string]any) ([]resource.Config, error) {
	return testComponents, nil
	}
	failingDiscovery.DiscoverResourcesFunc = func(ctx context.Context, extra map[string]any) ([]resource.Config, error) {
	return nil, errDiscoverFailed
	}
	workingDiscovery.DoFunc = testutils.EchoFunc
	failingDiscovery.DoFunc = func(
	ctx context.Context,
	cmd map[string]interface{},
	) (
	map[string]interface{},
	error,
	) {
	return nil, errDoFailed
	}
	testComponents := []resource.Config{createTestComponent("component-1"), createTestComponent("component-2")}
	workingDiscovery := &inject.DiscoveryService{}
	workingDiscovery.DiscoverResourcesFunc = func(ctx context.Context, extra map[string]any) ([]resource.Config, error) {
	return testComponents, nil
	}
	workingDiscovery.DoFunc = testutils.EchoFunc
	failingDiscovery := &inject.DiscoveryService{}
	failingDiscovery.DiscoverResourcesFunc = func(ctx context.Context, extra map[string]any) ([]resource.Config, error) {
	return nil, errDiscoverFailed
	}
	failingDiscovery.DoFunc = func(
	ctx context.Context,
	cmd map[string]interface{},
	) (
	map[string]interface{},
	error,
	) {
	return nil, errDoFailed
	}

[JohnN193]

rearranged the code so the working & failing injects were separated. Note because of the structure of the server tests I couldn't really do the same

[martha-johnston]

lgtm!