refactor: modernize idpscimcli CLI with Go 1.26 best practices

- Fix logger initialization order: configure log handler options before
  creating the handler, so log level/format from config takes effect.

- Replace os.Exit(1) in getGWSDirectoryService with error returns,
  making the function testable and letting cobra handle the exit.

- Fix show() to return errors instead of silently discarding marshal
  failures.

- Extract duplicated HTTP client builders into newSCIMHTTPClient() and
  newGWSHTTPClient() helpers, reducing 3 identical builder blocks to 1.

- Extract newAWSSCIMService() helper to deduplicate SCIM service
  creation across 3 AWS command handlers.

- Fix typos: "usrs" → "users", "Servive" → "Service" in help text.

- Use strings.TrimSuffix for config filename parsing instead of
  fragile index slicing.

- Add unit tests for show() covering JSON, YAML, default format,
  marshal errors, and empty structs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: christiangda

cmd/idpscimcli/cmd/aws.go

@@ -3,9 +3,7 @@ package cmd
 import (
 	"context"
 	"log/slog"
-	"time"
 
-	"github.com/slashdevops/httpx"
 	"github.com/slashdevops/idp-scim-sync/internal/version"
 	"github.com/slashdevops/idp-scim-sync/pkg/aws"
 	"github.com/spf13/cobra"
@@ -66,7 +64,7 @@ var (
 		Use:     "list",
 		Aliases: []string{"l"},
 		Short:   "return available users",
-		Long:    `list available usrs in AWS SSO SCIM`,
+		Long:    `list available users in AWS SSO SCIM`,
 		RunE:    runAWSUsersList,
 	}
 )
@@ -87,95 +85,65 @@ func init() {
 	awsUsersCmd.Flags().StringVarP(&filter, "filter", "q", "", "AWS SSO SCIM API Filter, example: --filter 'displayName eq \"User Bar\" and id eq \"12324\"'")
 }
 
+// newAWSSCIMService creates an AWS SCIM service with the configured HTTP client.
+func newAWSSCIMService() (*aws.SCIMService, error) {
+	svc, err := aws.NewSCIMService(newSCIMHTTPClient(), cfg.AWSSCIMEndpoint, cfg.AWSSCIMAccessToken)
+	if err != nil {
+		return nil, err
+	}
+	svc.UserAgent = "idp-scim-sync/" + version.Version
+	return svc, nil
+}
+
 func runAWSServiceConfig(_ *cobra.Command, _ []string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), reqTimeout)
 	defer cancel()
 
-	httpRetryClient := httpx.NewClientBuilder().
-		WithMaxRetries(10).
-		WithRetryStrategy(httpx.JitterBackoffStrategy).
-		WithRetryBaseDelay(500 * time.Millisecond).
-		WithRetryMaxDelay(10 * time.Second).
-		Build()
-
-	awsSCIMService, err := aws.NewSCIMService(httpRetryClient, cfg.AWSSCIMEndpoint, cfg.AWSSCIMAccessToken)
+	svc, err := newAWSSCIMService()
 	if err != nil {
-		slog.Error("error creating SCIM service", "error", err.Error())
 		return err
 	}
-	awsSCIMService.UserAgent = "idp-scim-sync/" + version.Version
 
-	awsServiceConfig, err := awsSCIMService.ServiceProviderConfig(ctx)
+	result, err := svc.ServiceProviderConfig(ctx)
 	if err != nil {
-		slog.Error("error getting service provider config", "error", err.Error())
 		return err
 	}
 
-	show(outFormat, awsServiceConfig)
-
-	return nil
+	return show(outFormat, result)
 }
 
 func runAWSGroupsList(_ *cobra.Command, _ []string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), reqTimeout)
 	defer cancel()
 
-	httpClient := httpx.NewClientBuilder().
-		WithMaxRetries(10).
-		WithRetryStrategy(httpx.JitterBackoffStrategy).
-		WithRetryBaseDelay(500 * time.Millisecond).
-		WithRetryMaxDelay(10 * time.Second).
-		WithMaxIdleConns(100).
-		WithMaxIdleConnsPerHost(100).
-		Build()
-
-	awsSCIMService, err := aws.NewSCIMService(httpClient, cfg.AWSSCIMEndpoint, cfg.AWSSCIMAccessToken)
+	svc, err := newAWSSCIMService()
 	if err != nil {
-		slog.Error("error creating SCIM service", "error", err.Error())
 		return err
 	}
-	awsSCIMService.UserAgent = "idp-scim-sync/" + version.Version
 
-	awsGroupsResponse, err := awsSCIMService.ListGroups(ctx, filter)
+	result, err := svc.ListGroups(ctx, filter)
 	if err != nil {
-		slog.Error("error listing groups", "error", err.Error())
 		return err
 	}
-	slog.Info("groups found", "groups", awsGroupsResponse.TotalResults)
-
-	show(outFormat, awsGroupsResponse)
+	slog.Info("groups found", "groups", result.TotalResults)
 
-	return nil
+	return show(outFormat, result)
 }
 
 func runAWSUsersList(_ *cobra.Command, _ []string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), reqTimeout)
 	defer cancel()
 
-	httpClient := httpx.NewClientBuilder().
-		WithMaxRetries(10).
-		WithRetryStrategy(httpx.JitterBackoffStrategy).
-		WithRetryBaseDelay(500 * time.Millisecond).
-		WithRetryMaxDelay(10 * time.Second).
-		WithMaxIdleConns(100).
-		WithMaxIdleConnsPerHost(100).
-		Build()
-
-	awsSCIMService, err := aws.NewSCIMService(httpClient, cfg.AWSSCIMEndpoint, cfg.AWSSCIMAccessToken)
+	svc, err := newAWSSCIMService()
 	if err != nil {
-		slog.Error("error creating SCIM service", "error", err.Error())
 		return err
 	}
-	awsSCIMService.UserAgent = "idp-scim-sync/" + version.Version
 
-	awsUsersResponse, err := awsSCIMService.ListUsers(ctx, filter)
+	result, err := svc.ListUsers(ctx, filter)
 	if err != nil {
-		slog.Error("error listing users", "error", err.Error())
 		return err
 	}
-	slog.Info("users found", "users", awsUsersResponse.TotalResults)
-
-	show(outFormat, awsUsersResponse)
+	slog.Info("users found", "users", result.TotalResults)
 
-	return nil
+	return show(outFormat, result)
 }

cmd/idpscimcli/cmd/common.go

@@ -7,17 +7,21 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
-// show resource structure as outFormat
-func show(outFormat string, resource any) {
-	switch outFormat {
-	case "json":
-		j, _ := json.MarshalIndent(resource, "", "  ")
-		fmt.Print(string(j))
+// show prints the resource in the specified output format to stdout.
+func show(format string, resource any) error {
+	switch format {
 	case "yaml":
-		y, _ := yaml.Marshal(resource)
-		fmt.Print(string(y))
+		b, err := yaml.Marshal(resource)
+		if err != nil {
+			return fmt.Errorf("error marshaling to YAML: %w", err)
+		}
+		fmt.Print(string(b))
 	default:
-		j, _ := json.MarshalIndent(resource, "", "  ")
-		fmt.Print(string(j))
+		b, err := json.MarshalIndent(resource, "", "  ")
+		if err != nil {
+			return fmt.Errorf("error marshaling to JSON: %w", err)
+		}
+		fmt.Println(string(b))
 	}
+	return nil
 }

cmd/idpscimcli/cmd/common_test.go

@@ -0,0 +1,52 @@
+//go:build unit
+
+package cmd
+
+import (
+	"testing"
+)
+
+func TestShow_JSON(t *testing.T) {
+	data := map[string]string{"key": "value"}
+
+	if err := show("json", data); err != nil {
+		t.Fatalf("show(json) returned error: %v", err)
+	}
+}
+
+func TestShow_YAML(t *testing.T) {
+	data := map[string]string{"key": "value"}
+
+	if err := show("yaml", data); err != nil {
+		t.Fatalf("show(yaml) returned error: %v", err)
+	}
+}
+
+func TestShow_DefaultIsJSON(t *testing.T) {
+	data := map[string]string{"key": "value"}
+
+	if err := show("unknown", data); err != nil {
+		t.Fatalf("show(unknown) returned error: %v", err)
+	}
+}
+
+func TestShow_JSONMarshalError(t *testing.T) {
+	// channels cannot be marshaled to JSON
+	data := make(chan int)
+
+	if err := show("json", data); err == nil {
+		t.Fatal("show(json) with unmarshalable data should return error")
+	}
+}
+
+func TestShow_EmptyStruct(t *testing.T) {
+	type empty struct{}
+
+	if err := show("json", empty{}); err != nil {
+		t.Fatalf("show(json) with empty struct returned error: %v", err)
+	}
+
+	if err := show("yaml", empty{}); err != nil {
+		t.Fatalf("show(yaml) with empty struct returned error: %v", err)
+	}
+}