Fix name getting set to empty on updates

The name field was getting set to empty on changes to ha replicas. This fixes the issue by using the previous known state for the name field on updates.

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/hashicorp/terraform-plugin-log v0.9.0
 	github.com/hashicorp/terraform-plugin-sdk/v2 v2.30.0
 	github.com/hashicorp/terraform-plugin-testing v1.2.0
+	github.com/stretchr/testify v1.7.2
 )
 
 require (
@@ -23,6 +24,7 @@ require (
 	github.com/armon/go-radix v1.0.0 // indirect
 	github.com/bgentry/speakeasy v0.1.0 // indirect
 	github.com/cloudflare/circl v1.3.3 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fatih/color v1.16.0 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
@@ -55,6 +57,7 @@ require (
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/oklog/run v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/posener/complete v1.2.3 // indirect
 	github.com/russross/blackfriday v1.6.0 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
@@ -72,4 +75,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20231106174013-bbf56f31fb17 // indirect
 	google.golang.org/grpc v1.59.0 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

internal/provider/provider_test.go

@@ -1,11 +1,14 @@
 package provider
 
 import (
+	"fmt"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-framework/providerserver"
 	"github.com/hashicorp/terraform-plugin-go/tfprotov6"
+	"github.com/stretchr/testify/require"
 )
 
 const (
@@ -41,6 +44,7 @@ var testAccProtoV6ProviderFactories = map[string]func() (tfprotov6.ProviderServe
 }
 
 type Config struct {
+	ResourceName    string
 	Name            string
 	Timeouts        Timeouts
 	MilliCPU        int64
@@ -50,6 +54,81 @@ type Config struct {
 	VpcID           int64
 }
 
+func (c *Config) WithName(name string) *Config {
+	c.Name = name
+	return c
+}
+
+func (c *Config) WithSpec(milliCPU, memoryGB int64) *Config {
+	c.MilliCPU = milliCPU
+	c.MemoryGB = memoryGB
+	return c
+}
+
+func (c *Config) WithVPC(ID int64) *Config {
+	c.VpcID = ID
+	return c
+}
+
+func (c *Config) WithHAReplica(enableHAReplica bool) *Config {
+	c.EnableHAReplica = enableHAReplica
+	return c
+}
+
+func (c *Config) String(t *testing.T) string {
+	c.setDefaults()
+	b := &strings.Builder{}
+	write := func(format string, a ...any) {
+		_, err := fmt.Fprintf(b, format, a...)
+		require.NoError(t, err)
+	}
+	_, err := fmt.Fprintf(b, "\n\n resource timescale_service %q { \n", c.ResourceName)
+	require.NoError(t, err)
+	if c.Name != "" {
+		write("name = %q \n", c.Name)
+	}
+	if c.EnableHAReplica {
+		write("enable_ha_replica = %t \n", c.EnableHAReplica)
+	}
+	if c.RegionCode != "" {
+		write("region_code = %q \n", c.RegionCode)
+	}
+	if c.VpcID != 0 {
+		write("vpc_id = %d \n", c.VpcID)
+	}
+	write(`
+			milli_cpu  = %d
+			memory_gb  = %d
+			timeouts = {
+				create = %q
+			}`+"\n",
+		c.MilliCPU, c.MemoryGB, c.Timeouts.Create)
+	write("}")
+	return b.String()
+}
+
+func (c *Config) setDefaults() {
+	if c.MilliCPU == 0 {
+		c.MilliCPU = 500
+	}
+	if c.MemoryGB == 0 {
+		c.MemoryGB = 2
+	}
+	if c.Timeouts.Create == "" {
+		c.Timeouts.Create = "10m"
+	}
+}
+
+// getConfig returns a configuration for a test step
+func getConfig(t *testing.T, cfgs ...*Config) string {
+	res := strings.Builder{}
+	res.WriteString(providerConfig)
+	for _, cfg := range cfgs {
+		res.WriteString(cfg.String(t))
+	}
+	return res.String()
+}
+
 type Timeouts struct {
 	Create string
 }

internal/provider/service_resource.go

@@ -101,6 +101,9 @@ The change has been taken into account but must still be propagated. You can run
 				Optional:            true,
 				// If the name attribute is absent, the provider will generate a default.
 				Computed: true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.UseStateForUnknown(),
+				},
 			},
 			"milli_cpu": schema.Int64Attribute{
 				MarkdownDescription: "Milli CPU",

internal/provider/service_resource_test.go

@@ -13,19 +13,20 @@ import (
 const DEFAULT_VPC_ID = 2074 // Default vpc id for test acc
 
 func TestServiceResource_Default_Success(t *testing.T) {
-	// Test resource creation succeeds and update is not allowed
+	// Test resource creation succeeds
+	config := &Config{
+		ResourceName: "resource",
+	}
 	resource.ParallelTest(t, resource.TestCase{
 		ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
 		PreCheck:                 func() { testAccPreCheck(t) },
 		Steps: []resource.TestStep{
 			// Create default and Read testing
 			{
-				Config: newServiceConfig(Config{
-					Name: "service resource test init",
-				}),
+				Config: getConfig(t, config),
 				Check: resource.ComposeAggregateTestCheckFunc(
 					// Verify the name is set.
-					resource.TestCheckResourceAttr("timescale_service.resource", "name", "service resource test init"),
+					resource.TestCheckResourceAttrSet("timescale_service.resource", "name"),
 					// Verify ID value is set in state.
 					resource.TestCheckResourceAttrSet("timescale_service.resource", "id"),
 					resource.TestCheckResourceAttrSet("timescale_service.resource", "password"),
@@ -39,47 +40,31 @@ func TestServiceResource_Default_Success(t *testing.T) {
 					resource.TestCheckNoResourceAttr("timescale_service.resource", "vpc_id"),
 				),
 			},
-			// Update service name
+			// Do a compute resize
 			{
-				Config: newServiceConfig(Config{
-					Name: "service resource test update",
-				}),
+				Config: getConfig(t, config.WithSpec(1000, 4)),
 				Check: resource.ComposeAggregateTestCheckFunc(
-					resource.TestCheckResourceAttr("timescale_service.resource", "name", "service resource test update"),
+					resource.TestCheckResourceAttr("timescale_service.resource", "milli_cpu", "1000"),
+					resource.TestCheckResourceAttr("timescale_service.resource", "memory_gb", "4"),
 				),
 			},
-			// Do a compute resize
+			// Update service name
 			{
-				Config: newServiceComputeResizeConfig(Config{
-					Name:     "service resource test update",
-					MilliCPU: 1000,
-					MemoryGB: 4,
-				}),
+				Config: getConfig(t, config.WithName("service resource test update")),
 				Check: resource.ComposeAggregateTestCheckFunc(
-					resource.TestCheckResourceAttr("timescale_service.resource", "milli_cpu", "1000"),
-					resource.TestCheckResourceAttr("timescale_service.resource", "memory_gb", "4"),
+					resource.TestCheckResourceAttr("timescale_service.resource", "name", "service resource test update"),
 				),
 			},
 			// Add VPC
 			{
-				Config: newServiceAddVpc(Config{
-					Name:     "service resource test update",
-					VpcID:    DEFAULT_VPC_ID,
-					MilliCPU: 1000,
-					MemoryGB: 4,
-				}),
+				Config: getConfig(t, config.WithVPC(DEFAULT_VPC_ID)),
 				Check: resource.ComposeAggregateTestCheckFunc(
 					resource.TestCheckResourceAttr("timescale_service.resource", "vpc_id", "2074"),
 				),
 			},
 			// Add HA replica and remove VPC
 			{
-				Config: newServiceAddHAReplica(Config{
-					Name:            "service resource test update",
-					EnableHAReplica: true,
-					MilliCPU:        1000,
-					MemoryGB:        4,
-				}),
+				Config: getConfig(t, config.WithVPC(0).WithHAReplica(true)),
 				Check: resource.ComposeAggregateTestCheckFunc(
 					resource.TestCheckNoResourceAttr("timescale_service.resource", "vpc_id"),
 					resource.TestCheckResourceAttr("timescale_service.resource", "enable_ha_replica", "true"),
@@ -219,53 +204,6 @@ func newServiceConfig(config Config) string {
 				}`, config.Name, config.Timeouts.Create)
 }
 
-func newServiceComputeResizeConfig(config Config) string {
-	if config.Timeouts.Create == "" {
-		config.Timeouts.Create = "10m"
-	}
-	return providerConfig + fmt.Sprintf(`
-		resource "timescale_service" "resource" {
-			name = %q
-			milli_cpu  = %d
-			memory_gb  = %d
-			timeouts = {
-				create = %q
-			}
-		}`, config.Name, config.MilliCPU, config.MemoryGB, config.Timeouts.Create)
-}
-
-func newServiceAddVpc(config Config) string {
-	if config.Timeouts.Create == "" {
-		config.Timeouts.Create = "10m"
-	}
-	return providerConfig + fmt.Sprintf(`
-		resource "timescale_service" "resource" {
-			name = %q
-			milli_cpu  = %d
-			memory_gb  = %d
-			vpc_id = %d
-			timeouts = {
-				create = %q
-			}
-		}`, config.Name, config.MilliCPU, config.MemoryGB, config.VpcID, config.Timeouts.Create)
-}
-
-func newServiceAddHAReplica(config Config) string {
-	if config.Timeouts.Create == "" {
-		config.Timeouts.Create = "10m"
-	}
-	return providerConfig + fmt.Sprintf(`
-		resource "timescale_service" "resource" {
-			name = %q
-			milli_cpu  = %d
-			memory_gb  = %d
-			enable_ha_replica = %t
-			timeouts = {
-				create = %q
-			}
-		}`, config.Name, config.MilliCPU, config.MemoryGB, config.EnableHAReplica, config.Timeouts.Create)
-}
-
 func newServiceCustomConfig(resourceName string, config Config) string {
 	if config.Timeouts.Create == "" {
 		config.Timeouts.Create = "30m"