The method MockComponent#getResourceType() returns the resource type of the resource used to construct the MockComponent - via Resource#getResourceType.
However, in actual use, the real Component implementation will only return the value of the sling:resourceType property if that property is set. Otherwise it will return the path of the resource, unless that path starts with a search path, in which case it will return the path of the resource with the search path removed.
It does not return the resource type as defined by Resource#getResourceType(), which will return the primary type if the sling:resourceType property is not defined. I do not believe there is any scenario under which the real implementation will return the primary type.
I believe the correct implementation of this method is something like this:
MockComponent.java:
thanks for the PR - looks good, it think the new behavior is correct