core: NodeAbstractResource correct default result from ProvidedBy

Previously we had a bug where we'd use the resource type name instead of
the provider name. Now we use the DefaultProviderConfig helper function
to extract the provider name from the resource type name.

terraform/node_resource_abstract.go

@@ -309,7 +309,7 @@ func (n *NodeAbstractResource) ProvidedBy() (addrs.AbsProviderConfig, bool) {
 	}
 
 	// Use our type and containing module path to guess a provider configuration address
-	return addrs.NewDefaultProviderConfig(n.Addr.Resource.Type).Absolute(n.Addr.Module), false
+	return n.Addr.Resource.DefaultProviderConfig().Absolute(n.Addr.Module), false
 }
 
 // GraphNodeProviderConsumer

terraform/transform_root_test.go

@@ -44,7 +44,7 @@ func TestRootTransformer(t *testing.T) {
 	actual := strings.TrimSpace(g.String())
 	expected := strings.TrimSpace(testTransformRootBasicStr)
 	if actual != expected {
-		t.Fatalf("bad:\n\n%s", actual)
+		t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
 	}
 
 	root, err := g.Root()