tfsdk: Introduce new ProviderServer functions, deprecate existing

.changelog/pending.txt

@@ -0,0 +1,11 @@
+```release-note:note
+tfsdk: The `NewProtocol6Server()` function has been deprecated in preference of `NewProtocol6ProviderServer()` and `NewProtocol6ProviderServerWithError()` functions, which will simplify muxing and testing implementations. The `NewProtocol6Server()` function will be removed in an upcoming minor release before v1.0.0.
+```
+
+```release-note:enhancement
+tfsdk: Added `NewProtocol6ProviderServer()` function, which can be directly used with terraform-plugin-go and terraform-plugin-mux.
+```
+
+```release-note:enhancement
+tfsdk: Added `NewProtocol6ProviderServerWithError()` function, which can be directly used with terraform-plugin-sdk acceptance testing.
+```

tfsdk/serve.go

@@ -38,12 +38,39 @@ type ServeOpts struct {
 
 // NewProtocol6Server returns a tfprotov6.ProviderServer implementation based
 // on the passed Provider implementation.
+//
+// Deprecated: Use NewProtocol6ProviderServer instead. This will be removed
+// in an upcoming minor version before v1.0.0.
 func NewProtocol6Server(p Provider) tfprotov6.ProviderServer {
 	return &server{
 		p: p,
 	}
 }
 
+// Returns a protocol version 6 ProviderServer implementation based on the
+// given Provider and suitable for usage with the terraform-plugin-go
+// tf6server.Serve() function and various terraform-plugin-mux functions.
+func NewProtocol6ProviderServer(p Provider) func() tfprotov6.ProviderServer {
+	return func() tfprotov6.ProviderServer {
+		return &server{
+			p: p,
+		}
+	}
+}
+
+// Returns a protocol version 6 ProviderServer implementation based on the
+// given Provider and suitable for usage with the terraform-plugin-sdk
+// acceptance testing helper/resource.TestCase.ProtoV6ProviderFactories.
+//
+// The error return is not currently used, but it may be in the future.
+func NewProtocol6ProviderServerWithError(p Provider) (func() tfprotov6.ProviderServer, error) {
+	return func() tfprotov6.ProviderServer {
+		return &server{
+			p: p,
+		}
+	}, nil
+}
+
 // Serve serves a provider, blocking until the context is canceled.
 func Serve(ctx context.Context, providerFunc func() Provider, opts ServeOpts) error {
 	var tf6serverOpts []tf6server.ServeOpt

tfsdk/serve_test.go

@@ -16,6 +16,39 @@ import (
 	"github.com/hashicorp/terraform-plugin-go/tftypes"
 )
 
+func TestNewProtocol6ProviderServer(t *testing.T) {
+	provider := &testServeProvider{}
+
+	providerServerFunc := NewProtocol6ProviderServer(provider)
+	providerServer := providerServerFunc()
+
+	// Simple verification
+	_, err := providerServer.GetProviderSchema(context.Background(), &tfprotov6.GetProviderSchemaRequest{})
+
+	if err != nil {
+		t.Fatalf("unexpected error calling ProviderServer: %s", err)
+	}
+}
+
+func TestNewProtocol6ProviderServerWithError(t *testing.T) {
+	provider := &testServeProvider{}
+
+	providerServerFunc, err := NewProtocol6ProviderServerWithError(provider)
+
+	if err != nil {
+		t.Fatalf("unexpected error creating ProviderServer: %s", err)
+	}
+
+	providerServer := providerServerFunc()
+
+	// Simple verification
+	_, err = providerServer.GetProviderSchema(context.Background(), &tfprotov6.GetProviderSchemaRequest{})
+
+	if err != nil {
+		t.Fatalf("unexpected error calling ProviderServer: %s", err)
+	}
+}
+
 func TestServerCancelInFlightContexts(t *testing.T) {
 	t.Parallel()