support init subcommand

cmd/init.go

@@ -0,0 +1,149 @@
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+	"github.com/vektah/gqlgen/codegen"
+	"gopkg.in/yaml.v2"
+)
+
+func init() {
+	rootCmd.AddCommand(initCmd)
+}
+
+var configComment = `
+# .gqlgen.yml example
+#
+# Refer to https://gqlgen.com/config/
+# for detailed .gqlgen.yml documentation.
+`
+
+var schemaDefault = `
+# GraphQL schema example
+#
+# https://gqlgen.com/getting-started/
+
+type Todo {
+  id: ID!
+  text: String!
+  done: Boolean!
+  user: User!
+}
+
+type User {
+  id: ID!
+  name: String!
+}
+
+type Query {
+  todos: [Todo!]!
+}
+
+input NewTodo {
+  text: String!
+  userId: String!
+}
+
+type Mutation {
+  createTodo(input: NewTodo!): Todo!
+}
+`
+
+var initCmd = &cobra.Command{
+	Use:   "init",
+	Short: "Generate .gqlgen.yml",
+	Long:  "",
+	Run: func(cmd *cobra.Command, args []string) {
+		initConfig()
+		initSchema()
+	},
+}
+
+func initConfig() {
+	var config *codegen.Config
+	var err error
+	if configFilename != "" {
+		config, err = codegen.LoadConfig(configFilename)
+	} else {
+		config, err = codegen.LoadDefaultConfig()
+	}
+	if os.IsNotExist(errors.Cause(err)) {
+		// ok
+		if configFilename == "" {
+			configFilename = ".gqlgen.yml"
+		}
+		config = &codegen.Config{
+			SchemaFilename: "schema.graphql",
+			Model:          codegen.PackageConfig{Filename: "models_gen.go"},
+			Exec:           codegen.PackageConfig{Filename: "generated.go"},
+		}
+
+	} else if !os.IsNotExist(errors.Cause(err)) {
+		fmt.Fprintln(os.Stderr, "config file is already exists")
+		os.Exit(0)
+	} else if err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		os.Exit(1)
+	}
+
+	if schemaFilename != "" {
+		config.SchemaFilename = schemaFilename
+	}
+	if models != "" {
+		config.Model.Filename = models
+	}
+	if output != "" {
+		config.Exec.Filename = output
+	}
+	if packageName != "" {
+		config.Exec.Package = packageName
+	}
+	if modelPackageName != "" {
+		config.Model.Package = modelPackageName
+	}
+	if typemap != "" {
+		config.Models = loadModelMap()
+	}
+
+	var buf bytes.Buffer
+	buf.WriteString(strings.TrimSpace(configComment))
+	buf.WriteString("\n\n")
+	{
+		var b []byte
+		b, err = yaml.Marshal(config)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "unable to marshal yaml: "+err.Error())
+			os.Exit(1)
+		}
+		buf.Write(b)
+	}
+
+	err = ioutil.WriteFile(configFilename, buf.Bytes(), 0644)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "unable to write config file: "+err.Error())
+		os.Exit(1)
+	}
+}
+
+func initSchema() {
+	if schemaFilename == "" {
+		schemaFilename = "schema.graphql"
+	}
+
+	_, err := os.Stat(schemaFilename)
+	if !os.IsNotExist(err) {
+		return
+	}
+
+	err = ioutil.WriteFile(schemaFilename, []byte(strings.TrimSpace(schemaDefault)), 0644)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "unable to write schema file: "+err.Error())
+		os.Exit(1)
+	}
+}