add pager to describe config command

cmd/describe.go

@@ -15,5 +15,7 @@ var describeCmd = &cobra.Command{
 
 func init() {
 	describeCmd.PersistentFlags().StringP("query", "q", "", "Query the results of an `atmos describe` command using `yq` expressions")
+	describeCmd.PersistentFlags().String("pager", "true", "Disable the paging user experience")
+
 	RootCmd.AddCommand(describeCmd)
 }

cmd/describe_config.go

@@ -4,6 +4,8 @@
 	"github.com/spf13/cobra"
 
 	e "github.com/cloudposse/atmos/internal/exec"
+	cfg "github.com/cloudposse/atmos/pkg/config"
+	"github.com/cloudposse/atmos/pkg/schema"
 	u "github.com/cloudposse/atmos/pkg/utils"
 )
 
@@ -14,11 +16,37 @@
 	Long:               "This command displays the final, deep-merged CLI configuration after combining all relevant configuration files.",
 	FParseErrWhitelist: struct{ UnknownFlags bool }{UnknownFlags: false},
 	Args:               cobra.NoArgs,
-	Run: func(cmd *cobra.Command, args []string) {
-		err := e.ExecuteDescribeConfigCmd(cmd, args)
+	RunE: func(cmd *cobra.Command, args []string) error {
+		flags := cmd.Flags()
+
+		format, err := flags.GetString("format")
+		if err != nil {
+			return err
+		}
+
+		query, err := flags.GetString("query")
+		if err != nil {
+			return err
+		}
+
+		atmosConfig, err := cfg.InitCliConfig(schema.ConfigAndStacksInfo{}, false)
+		if err != nil {
+			return err
+		}
+
+		if cmd.Flags().Changed("pager") {
+			// TODO: update this post pr:https://github.com/cloudposse/atmos/pull/1174 is merged
+			atmosConfig.Settings.Terminal.Pager, err = cmd.Flags().GetString("pager")
+			if err != nil {
+				return err
+			}
+		}
+
+		err = e.NewDescribeConfig(&atmosConfig).ExecuteDescribeConfigCmd(query, format, "")
 		if err != nil {
 			u.PrintErrorMarkdown("", err, "")
 		}
+		return nil
 	},
 }
 

cmd/docs.go

@@ -102,7 +102,7 @@
 				u.LogErrorAndExit(err)
 			}
 
-			pager := atmosConfig.Settings.Terminal.Pager
+			pager := atmosConfig.Settings.Terminal.IsPagerEnabled()
 			if !pager && atmosConfig.Settings.Docs.Pagination {
 				pager = atmosConfig.Settings.Docs.Pagination
 				u.LogWarning("'settings.docs.pagination' is deprecated and will be removed in a future version. Please use 'settings.terminal.pager' instead")

internal/exec/describe_config.go

@@ -1,51 +1,95 @@
 package exec
 
 import (
-	u "github.com/cloudposse/atmos/pkg/utils"
-	"github.com/spf13/cobra"
+	"fmt"
+
+	log "github.com/charmbracelet/log"
+	"github.com/cloudposse/atmos/internal/tui/templates/term"
+	"github.com/cloudposse/atmos/pkg/pager"
+	"github.com/cloudposse/atmos/pkg/schema"
 
-	cfg "github.com/cloudposse/atmos/pkg/config"
+	u "github.com/cloudposse/atmos/pkg/utils"
 )
 
-// ExecuteDescribeConfigCmd executes `describe config` command
-func ExecuteDescribeConfigCmd(cmd *cobra.Command, args []string) error {
-	flags := cmd.Flags()
+const describeConfigTitle = "Atmos Config"
 
-	format, err := flags.GetString("format")
-	if err != nil {
-		return err
-	}
+type DescribeConfigFormatError struct {
+	format string
+}
 
-	query, err := flags.GetString("query")
-	if err != nil {
-		return err
-	}
+func (e DescribeConfigFormatError) Error() string {
+	return fmt.Sprintf("invalid 'format': %s", e.format)
+}
 
-	info, err := ProcessCommandLineArgs("", cmd, args, nil)
-	if err != nil {
-		return err
-	}
+var ErrTTYNotSupported = fmt.Errorf("tty not supported for this command")
 
-	atmosConfig, err := cfg.InitCliConfig(info, false)
-	if err != nil {
-		return err
-	}
+type describeConfigExec struct {
+	atmosConfig           *schema.AtmosConfiguration
+	pageCreator           pager.PageCreator
+	printOrWriteToFile    func(format string, file string, data any) error
+	IsTTYSupportForStdout func() bool
+}
 
-	var res any
+func NewDescribeConfig(atmosConfig *schema.AtmosConfiguration) *describeConfigExec {
+	return &describeConfigExec{
+		atmosConfig:           atmosConfig,
+		pageCreator:           pager.New(),
+		printOrWriteToFile:    printOrWriteToFile,
+		IsTTYSupportForStdout: term.IsTTYSupportForStdout,
+	}
+}
 
+// ExecuteDescribeConfigCmd executes `describe config` command.
+func (d *describeConfigExec) ExecuteDescribeConfigCmd(query, format, output string) error {
+	var res *schema.AtmosConfiguration
+	var err error
 	if query != "" {
-		res, err = u.EvaluateYqExpression(&atmosConfig, atmosConfig, query)
+		res, err = u.EvaluateYqExpressionWithType[schema.AtmosConfiguration](d.atmosConfig, *d.atmosConfig, query)
 		if err != nil {
 			return err
 		}
 	} else {
-		res = atmosConfig
+		res = d.atmosConfig
 	}
 
-	err = printOrWriteToFile(format, "", res)
-	if err != nil {
-		return err
+	if d.atmosConfig.Settings.Terminal.IsPagerEnabled() {
+		err = d.viewConfig(format, res)
+		switch err.(type) {
+		case DescribeConfigFormatError:
+			return err
+		case nil:
+			return nil
+		default:
+			log.Debug("Failed to use pager")
+		}
 	}
+	return d.printOrWriteToFile(format, output, res)
+}
 
+func (d *describeConfigExec) viewConfig(format string, data *schema.AtmosConfiguration) error {
+	if !d.IsTTYSupportForStdout() {
+		return ErrTTYNotSupported
+	}
+	var content string
+	var err error
+	switch format {
+	case "yaml":
+		content, err = u.GetAtmosConfigYAML(data)
+		if err != nil {
+			return err
+		}
+	case "json":
+		content, err = u.GetAtmosConfigJSON(data)
+		if err != nil {
+			return err
+		}
+	default:
+		return DescribeConfigFormatError{
+			format,
+		}
+	}
+	if err := d.pageCreator.Run(describeConfigTitle, content); err != nil {
+		return err
+	}
 	return nil
 }

internal/exec/describe_config_test.go

@@ -0,0 +1,128 @@
+package exec
+
+import (
+	"testing"
+
+	"github.com/cloudposse/atmos/pkg/pager"
+	"github.com/cloudposse/atmos/pkg/schema"
+	gomock "github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestErrInvalidFormat_Error(t *testing.T) {
+	err := DescribeConfigFormatError{format: "invalid"}
+	assert.Equal(t, "invalid 'format': invalid", err.Error())
+}
+
+func TestDescribeConfig(t *testing.T) {
+	// Setup test data
+	config := &schema.AtmosConfiguration{
+		Components: schema.Components{
+			Terraform: schema.Terraform{
+				BasePath: "something",
+			},
+		},
+		Settings: schema.AtmosSettings{
+			Terminal: schema.Terminal{
+				Pager: "less",
+			},
+		},
+	}
+
+	t.Run("NewDescribeConfig", func(t *testing.T) {
+		dc := NewDescribeConfig(config)
+		assert.Equal(t, config, dc.atmosConfig)
+		assert.NotNil(t, dc.pageCreator)
+		assert.NotNil(t, dc.printOrWriteToFile)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_NoQuery_YAML_TTY", func(t *testing.T) {
+		// Mock dependencies
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+
+		mockPager := pager.NewMockPageCreator(ctrl)
+		mockPager.EXPECT().Run(describeConfigTitle, gomock.Any()).Return(nil)
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			pageCreator:           mockPager,
+			IsTTYSupportForStdout: func() bool { return true },
+		}
+
+		err := dc.ExecuteDescribeConfigCmd("", "yaml", "")
+		assert.NoError(t, err)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_NoQuery_JSON_TTY", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+		mockPager := pager.NewMockPageCreator(ctrl)
+		mockPager.EXPECT().Run(describeConfigTitle, gomock.Any()).Return(nil)
+
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			pageCreator:           mockPager,
+			IsTTYSupportForStdout: func() bool { return true },
+		}
+
+		err := dc.ExecuteDescribeConfigCmd("", "json", "")
+		assert.NoError(t, err)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_NoQuery_InvalidFormat_TTY", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			IsTTYSupportForStdout: func() bool { return true },
+		}
+
+		err := dc.ExecuteDescribeConfigCmd("", "invalid", "")
+		assert.Error(t, err)
+		assert.Equal(t, DescribeConfigFormatError{format: "invalid"}, err)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_NoQuery_NoTTY", func(t *testing.T) {
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			IsTTYSupportForStdout: func() bool { return false },
+			printOrWriteToFile: func(format, file string, data any) error {
+				assert.Equal(t, "yaml", format)
+				assert.Equal(t, "", file)
+				assert.Equal(t, config, data)
+				return nil
+			},
+		}
+
+		err := dc.ExecuteDescribeConfigCmd("", "yaml", "")
+		assert.NoError(t, err)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_WithQuery", func(t *testing.T) {
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			IsTTYSupportForStdout: func() bool { return false },
+			printOrWriteToFile: func(format, file string, data any) error {
+				assert.Equal(t, "yaml", format)
+				assert.Equal(t, "", file)
+				assert.Equal(t, config, data)
+				return nil
+			},
+		}
+
+		err := dc.ExecuteDescribeConfigCmd("", "yaml", "")
+		assert.NoError(t, err)
+	})
+
+	t.Run("ExecuteDescribeConfigCmd_WithQuery_EvalError", func(t *testing.T) {
+		dc := &describeConfigExec{
+			atmosConfig:           config,
+			IsTTYSupportForStdout: func() bool { return false },
+		}
+
+		err := dc.ExecuteDescribeConfigCmd(".component.terraform[", "yaml", "")
+		assert.Error(t, err)
+		assert.Equal(t, "EvaluateYqExpressionWithType: failed to evaluate YQ expression '.component.terraform[': bad expression, could not find matching `]`", err.Error())
+	})
+}

pkg/config/default.go

@@ -55,7 +55,7 @@ var (
 			ListMergeStrategy: "replace",
 			Terminal: schema.Terminal{
 				MaxWidth: templates.GetTerminalWidth(),
-				Pager:    true,
+				Pager:    "less",
 				Colors:   true,
 				Unicode:  true,
 				SyntaxHighlighting: schema.SyntaxHighlighting{

pkg/config/load.go

@@ -99,6 +99,8 @@ func setEnv(v *viper.Viper) {
 	bindEnv(v, "settings.gitlab_token", "GITLAB_TOKEN")
 	bindEnv(v, "settings.inject_gitlab_token", "ATMOS_INJECT_GITLAB_TOKEN")
 	bindEnv(v, "settings.atmos_gitlab_token", "ATMOS_GITLAB_TOKEN")
+
+	bindEnv(v, "settings.terminal.pager", "ATMOS_PAGER", "PAGER")
 }
 
 func bindEnv(v *viper.Viper, key ...string) {
@@ -115,6 +117,8 @@ func setDefaultConfiguration(v *viper.Viper) {
 	v.SetDefault("settings.inject_github_token", true)
 	v.SetDefault("logs.file", "/dev/stderr")
 	v.SetDefault("logs.level", "Info")
+
+	v.SetDefault("settings.terminal.pager", true)
 	v.SetDefault("docs.generate.readme.output", "./README.md")
 }