[Circle-11767] config expand command (#27)

* Adding most basic version of expand.

* Moving expand under the config command.

* Setting the token when calling expand config.

* Adding config file to expand config.

* Breaking out query and load for expand command.

* Using load and query in validate.

* Using the same response type for validate and expand.

* Inlining variables map initialization.

* Pulling out error processing for config commands.

* Fixing linting errors.

* Cleaning up config_test

* Actually testing the graphql request is correct.

* Testing gql errors.

* Testing console output.

* Using persistent flags to pass the config path to validate and expand.

* Adding tests around validate.

* Documenting verify json handler.

* Updating with PR feedback.

* Dep ensure

.gitignore

@@ -3,3 +3,4 @@ TODO
 circleci-cli
 coverage.txt
 dist/
+.vscode

cmd/config.go

@@ -3,7 +3,6 @@ package cmd
 import (
 	"bytes"
 	"context"
-	"fmt"
 	"io/ioutil"
 
 	"github.com/pkg/errors"
@@ -28,68 +27,133 @@ var validateCommand = &cobra.Command{
 	RunE:    validateConfig,
 }
 
+var expandCommand = &cobra.Command{
+	Use:   "expand",
+	Short: "Expand the config.",
+	RunE:  expandConfig,
+}
+
 func init() {
-	validateCommand.Flags().StringVarP(&configPath, "path", "p", ".circleci/config.yml", "path to build config")
+	configCmd.PersistentFlags().StringVarP(&configPath, "path", "p", ".circleci/config.yml", "path to build config")
 	configCmd.AddCommand(validateCommand)
+	configCmd.AddCommand(expandCommand)
 }
 
-func validateConfig(cmd *cobra.Command, args []string) error {
+// Define a structure that matches the result of the GQL
+// query, so that we can use mapstructure to convert from
+// nested maps to a strongly typed struct.
+type buildConfigResponse struct {
+	BuildConfig struct {
+		Valid      bool
+		SourceYaml string
+		OutputYaml string
+
+		Errors []struct {
+			Message string
+		}
+	}
+}
 
+func queryAPI(query string, variables map[string]string, response interface{}) error {
 	ctx := context.Background()
 
-	// Define a structure that matches the result of the GQL
-	// query, so that we can use mapstructure to convert from
-	// nested maps to a strongly typed struct.
-	type validateResult struct {
-		BuildConfig struct {
-			Valid      bool
-			SourceYaml string
-			Errors     []struct {
-				Message string
-			}
-		}
+	request := graphql.NewRequest(query)
+	request.Header.Set("Authorization", viper.GetString("token"))
+	for varName, varValue := range variables {
+		request.Var(varName, varValue)
+	}
+
+	client := graphql.NewClient(viper.GetString("endpoint"))
+
+	return client.Run(ctx, request, response)
+}
+
+func loadYaml(path string) (string, error) {
+	config, err := ioutil.ReadFile(path)
+
+	if err != nil {
+		return "", errors.Wrapf(err, "Could not load config file at %s", path)
+	}
+
+	return string(config), nil
+}
+
+func (response buildConfigResponse) processErrors() error {
+	var buffer bytes.Buffer
+
+	buffer.WriteString("\n")
+	for i := range response.BuildConfig.Errors {
+		buffer.WriteString("-- ")
+		buffer.WriteString(response.BuildConfig.Errors[i].Message)
+		buffer.WriteString(",\n")
 	}
 
-	request := graphql.NewRequest(`
+	return errors.New(buffer.String())
+}
+
+func validateConfig(cmd *cobra.Command, args []string) error {
+	query := `
 		query ValidateConfig ($config: String!) {
 			buildConfig(configYaml: $config) {
 				valid,
 				errors { message },
 				sourceYaml
 			}
-		}`)
-
-	config, err := ioutil.ReadFile(configPath)
+		}`
 
+	config, err := loadYaml(configPath)
 	if err != nil {
-		return errors.Wrapf(err, "Could not load config file at %s", configPath)
+		return err
 	}
 
-	request.Var("config", string(config))
+	variables := map[string]string{
+		"config": config,
+	}
 
-	client := graphql.NewClient(viper.GetString("endpoint"))
+	var response buildConfigResponse
+	err = queryAPI(query, variables, &response)
+	if err != nil {
+		return errors.New("Unable to validate config")
+	}
 
-	var result validateResult
+	if !response.BuildConfig.Valid {
+		return response.processErrors()
+	}
 
-	err = client.Run(ctx, request, &result)
+	Logger.Infoln("Config is valid")
+	return nil
+}
 
+func expandConfig(cmd *cobra.Command, args []string) error {
+	query := `
+		query ExpandConfig($config: String!) {
+			buildConfig(configYaml: $config) {
+				outputYaml
+				valid
+				errors { message }
+			}
+		}
+	`
+
+	config, err := loadYaml(configPath)
 	if err != nil {
-		return errors.Wrap(err, "GraphQL query failed")
+		return err
 	}
 
-	if !result.BuildConfig.Valid {
-
-		var buffer bytes.Buffer
+	variables := map[string]string{
+		"config": config,
+	}
 
-		for i := range result.BuildConfig.Errors {
-			buffer.WriteString(result.BuildConfig.Errors[i].Message)
-			buffer.WriteString("\n")
-		}
+	var response buildConfigResponse
+	err = queryAPI(query, variables, &response)
+	if err != nil {
+		return errors.New("Unable to expand config")
+	}
 
-		return fmt.Errorf("config file is invalid:\n%s", buffer.String())
+	if !response.BuildConfig.Valid {
+		return response.processErrors()
 	}
 
-	fmt.Println("Config is valid")
+	Logger.Info(response.BuildConfig.OutputYaml)
 	return nil
-
 }