introduce list-ignore command and append mode in dump command

cmd/dump.go

@@ -2,6 +2,8 @@ package cmd
 
 import (
 	"log"
+	"path/filepath"
+	"strings"
 
 	"github.com/simonwhitaker/gibo/utils"
 	"github.com/spf13/cobra"
@@ -17,10 +19,43 @@ var dumpCmd = &cobra.Command{
 	Args:      cobra.MinimumNArgs(1),
 	ValidArgs: utils.ListBoilerplatesNoError(),
 	Run: func(cmd *cobra.Command, args []string) {
-		for _, boilerplate := range args {
-			if err := utils.PrintBoilerplate(boilerplate); err != nil {
-				log.Fatalf("On dumping %v: %v", boilerplate, err)
+		if isAppendMode(args) {
+			results, err := findBoilerplatesInGitignoreFile(filepath.Join(".", gitignoreFileName))
+			if err != nil {
+				log.Fatal(err.Error())
 			}
+			dumpBoilerplate(concatNames(results, args))
+		} else {
+			dumpBoilerplate(args)
 		}
 	},
 }
+
+func concatNames(results []string, args []string) []string {
+	for _, arg := range args {
+		if strings.HasPrefix(arg, "+") {
+			results = append(results, arg[1:])
+		} else {
+			results = append(results, arg)
+		}
+	}
+	return results
+}
+
+func isAppendMode(args []string) bool {
+	for _, arg := range args {
+		if strings.HasPrefix(arg, "+") {
+			return true
+		}
+	}
+	return false
+}
+
+func dumpBoilerplate(args []string) error {
+	for _, boilerplate := range args {
+		if err := utils.PrintBoilerplate(boilerplate); err != nil {
+			log.Fatalf("On dumping %v: %v", boilerplate, err)
+		}
+	}
+	return nil
+}

cmd/list-ignore.go

@@ -0,0 +1,99 @@
+package cmd
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/simonwhitaker/gibo/utils"
+	"github.com/spf13/cobra"
+	"golang.org/x/term"
+)
+
+const gitignoreFileName string = ".gitignore"
+
+func init() {
+	giboCmd.AddCommand(listIgnoreCmd)
+}
+
+var listIgnoreCmd = &cobra.Command{
+	Use:   "list-ignore",
+	Short: "List boilerplates in the .gitignore file",
+	Run: func(cmd *cobra.Command, args []string) {
+		list, err := findRegisteredBoilerplates(args)
+		if err != nil {
+			log.Fatal(err)
+		}
+		if term.IsTerminal(int(os.Stdout.Fd())) {
+			w, _, err := term.GetSize(int(os.Stdout.Fd()))
+			if err == nil {
+				utils.PrintInColumns(list, w)
+				os.Exit(0)
+			}
+		}
+		for _, el := range list {
+			fmt.Println(el)
+		}
+	},
+}
+
+func findRegisteredBoilerplates(args []string) ([]string, error) {
+	if len(args) == 0 {
+		return findBoilerplatesInGitignoreFile(filepath.Join(".", gitignoreFileName))
+	}
+	gitIgnorePath := args[0]
+	if filepath.Base(gitIgnorePath) == gitignoreFileName {
+		gitIgnorePath = filepath.Join(gitIgnorePath, gitignoreFileName)
+	}
+	return findBoilerplatesInGitignoreFile(gitIgnorePath)
+}
+
+func Exists(filename string) bool {
+	_, err := os.Stat(filename)
+	return err == nil
+}
+
+func findBoilerplatesInGitignoreFile(gitIgnoreFile string) ([]string, error) {
+	if !Exists(gitIgnoreFile) {
+		return []string{}, nil
+	}
+	in, err := os.Open(gitIgnoreFile)
+	if err != nil {
+		return nil, err
+	}
+	defer in.Close()
+
+	var results []string
+	reader := bufio.NewReader(in)
+	for {
+		line, _, err := reader.ReadLine()
+		results = appendBoilerplateNameIfNeeded(results, string(line))
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
+	return results, nil
+}
+
+func appendBoilerplateNameIfNeeded(results []string, line string) []string {
+	if isBoilerplateName(line) {
+		results = append(results, extractBoilerplateName(line))
+	}
+	return results
+}
+
+func extractBoilerplateName(line string) string {
+	index := strings.LastIndex(line, "/")
+	return strings.TrimSuffix(line[index+1:], ".gitignore")
+}
+
+func isBoilerplateName(line string) bool {
+	return strings.HasPrefix(line, "###") && strings.HasSuffix(line, ".gitignore")
+}