Add main function

.gitignore

@@ -1,2 +1,3 @@
 .idea
 /vendor
+header

configuration.go

@@ -1,4 +1,4 @@
-package header
+package main
 
 import (
 	"bufio"
@@ -8,26 +8,30 @@ import (
 	"strings"
 )
 
+type Configuration struct {
+	HeaderFile   string            `json:"headerFile"`
+	CommentStyle string            `json:"style"`
+	Includes     []string          `json:"includes"`
+	Excludes     []string          `json:"excludes"`
+	TemplateData map[string]string `json:"data"`
+}
+
 type configuration struct {
 	HeaderContents string
 	Includes       []string
 	Excludes       []string
 	writer         io.Writer
 }
 
-func NewConfiguration(headerFile string,
-	style CommentStyle,
-	includes []string,
-	excludes []string,
-	data map[string]string) (*configuration, error) {
-	contents, err := parseTemplate(headerFile, data, style)
+func ParseConfiguration(config Configuration) (*configuration, error) {
+	contents, err := parseTemplate(config.HeaderFile, config.TemplateData, newCommentStyle(config.CommentStyle))
 	if err != nil {
 		return nil, err
 	}
 	return &configuration{
 		HeaderContents: contents,
-		Includes:       includes,
-		Excludes:       excludes,
+		Includes:       config.Includes,
+		Excludes:       config.Excludes,
 	}, nil
 }
 

configuration_test.go

@@ -1,4 +1,4 @@
-package header_test
+package main_test
 
 import (
 	. "github.com/fbiville/header"
@@ -9,40 +9,40 @@ import (
 func TestConfigurationInitWithLineCommentStyle(t *testing.T) {
 	I := NewGomegaWithT(t)
 
-	configuration, err := NewConfiguration(
-		"fixtures/license.txt",
-		SlashSlash,
-		[]string{"*.txt"},
-		[]string{},
-		map[string]string{
+	configuration, err := ParseConfiguration(Configuration{
+		HeaderFile:   "fixtures/license.txt",
+		CommentStyle: "SlashSlash",
+		Includes:     []string{"*.txt"},
+		Excludes:     []string{},
+		TemplateData: map[string]string{
 			"Year":  "2018",
 			"Owner": "ACME Labs",
-		})
+		}})
 
 	I.Expect(err).To(BeNil())
 	I.Expect(configuration.HeaderContents).To(Equal(`// Copyright 2018 ACME Labs
-// 
+//
 // Some fictional license`))
 	I.Expect(configuration.Includes).To(Equal([]string{"*.txt"}))
 }
 
 func TestConfigurationInitWithBlockCommentStyle(t *testing.T) {
 	I := NewGomegaWithT(t)
 
-	configuration, err := NewConfiguration(
-		"fixtures/license.txt",
-		SlashStar,
-		[]string{"*.txt"},
-		[]string{},
-		map[string]string{
+	configuration, err := ParseConfiguration(Configuration{
+		HeaderFile:   "fixtures/license.txt",
+		CommentStyle: "SlashStar",
+		Includes:     []string{"*.txt"},
+		Excludes:     []string{},
+		TemplateData: map[string]string{
 			"Year":  "2018",
 			"Owner": "ACME Labs",
-		})
+		}})
 
 	I.Expect(err).To(BeNil())
-	I.Expect(configuration.HeaderContents).To(Equal(`/* 
+	I.Expect(configuration.HeaderContents).To(Equal(`/*
  * Copyright 2018 ACME Labs
- * 
+ *
  * Some fictional license
  */`))
 	I.Expect(configuration.Includes).To(Equal([]string{"*.txt"}))

header.go

@@ -1,17 +1,17 @@
-package header
+package main
 
 import (
 	"bufio"
 	. "bytes"
 	"fmt"
+	"github.com/mattn/go-zglob"
 	"io/ioutil"
 	"os"
-	"path/filepath"
 )
 
-func Insert(config *configuration) {
+func InsertHeader(config *configuration) {
 	for _, includePattern := range config.Includes {
-		matches, err := filepath.Glob(includePattern)
+		matches, err := zglob.Glob(includePattern)
 		if err != nil {
 			panic(err)
 		}
@@ -31,7 +31,7 @@ func exclude(strings []string, exclusionPatterns []string) []string {
 
 func matches(str string, exclusionPatterns []string) bool {
 	for _, exclusionPattern := range exclusionPatterns {
-		matched, _ := filepath.Match(exclusionPattern, str)
+		matched, _ := zglob.Match(exclusionPattern, str)
 		if matched {
 			return true
 		}
@@ -50,18 +50,26 @@ func insertInMatchedFiles(config *configuration, files []string) {
 			continue
 		}
 
-		newContents := append([]byte(fmt.Sprintf("%s%s", config.HeaderContents, "\n")), bytes...)
-		var writer = config.writer
-		if writer == nil {
-			openFile, err := os.Open(file)
-			if err != nil {
-				panic(err)
-			}
-			defer openFile.Close()
-			writer = bufio.NewWriter(openFile)
-		}
-
-		writer.Write(newContents)
+		newContents := append([]byte(fmt.Sprintf("%s%s", config.HeaderContents, "\n\n")), bytes...)
+		writeToFile(config, file, newContents)
+	}
+}
 
+func writeToFile(config *configuration, file string, newContents []byte) {
+	var writer = config.writer
+	if writer == nil {
+		openFile, err := os.OpenFile(file, os.O_WRONLY, os.ModeAppend)
+		if err != nil {
+			panic(err)
+		}
+		_, err = openFile.Write(newContents)
+		openFile.Close()
+		if err != nil {
+			panic(err)
+		}
+	} else {
+		bufferedWriter := bufio.NewWriter(writer)
+		bufferedWriter.Write(newContents)
+		bufferedWriter.Flush()
 	}
 }

header_test.go

@@ -1,4 +1,4 @@
-package header
+package main
 
 import (
 	"bufio"
@@ -18,11 +18,12 @@ func TestHeaderWrite(t *testing.T) {
 		writer:   writer,
 	}
 
-	Insert(&configuration)
+	InsertHeader(&configuration)
 	writer.Flush()
 
 	I.Expect(stringBuilder.String()).To(Equal(`// some multi-line header
 // with some text
+
 hello
 world`))
 }
@@ -38,7 +39,7 @@ func TestHeaderDoesNotWriteTwice(t *testing.T) {
 		writer:   writer,
 	}
 
-	Insert(&configuration)
+	InsertHeader(&configuration)
 	writer.Flush()
 
 	I.Expect(stringBuilder.String()).To(Equal(``))
@@ -56,10 +57,11 @@ func TestHeaderWriteWithExcludes(t *testing.T) {
 		writer:   writer,
 	}
 
-	Insert(&configuration)
+	InsertHeader(&configuration)
 	writer.Flush()
 
 	I.Expect(stringBuilder.String()).To(Equal(`// some header
+
 bonjour
 le world`))
 }

line_comment.go

@@ -1,4 +1,4 @@
-package header
+package main
 
 import (
 	"fmt"
@@ -11,6 +11,17 @@ const (
 	SlashSlash
 )
 
+func newCommentStyle(str string) CommentStyle {
+	switch str {
+	case "SlashStar":
+		return SlashStar
+	case "SlashSlash":
+		return SlashSlash
+	default:
+		panic(unknownStyleError())
+	}
+}
+
 func (style *CommentStyle) opening() bool {
 	return *style == SlashStar
 }
@@ -22,7 +33,7 @@ func (style *CommentStyle) closing() bool {
 func (style *CommentStyle) open() string {
 	switch *style {
 	case SlashStar:
-		return "/* "
+		return "/*"
 	default:
 		panic(unknownSurroundingCommentError())
 	}
@@ -38,21 +49,24 @@ func (style *CommentStyle) close() string {
 }
 
 func (style *CommentStyle) apply(line string) string {
-	return fmt.Sprintf("%s%s", style.commentSymbol(), line)
+	if line == "" {
+		return style.commentSymbol()
+	}
+	return fmt.Sprintf("%s %s", style.commentSymbol(), line)
 }
 
 func (style *CommentStyle) commentSymbol() string {
 	switch *style {
 	case SlashSlash:
-		return "// "
+		return "//"
 	case SlashStar:
-		return " * "
+		return " *"
 	default:
-		panic(unknownCommentError())
+		panic(unknownStyleError())
 	}
 }
 
-func unknownCommentError() string {
+func unknownStyleError() string {
 	return "Unexpected comment style, must be one of: SlashSlash, SlashStar"
 }
 

main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"io/ioutil"
+)
+
+func main() {
+	rawConfiguration := readConfiguration()
+	configuration, err := ParseConfiguration(rawConfiguration)
+	if err != nil {
+		panic(err)
+	}
+	InsertHeader(configuration)
+}
+
+func readConfiguration() Configuration {
+	configFile := flag.String("configuration", "license.json", "Path to configuration file")
+	flag.Parse()
+	file, err := ioutil.ReadFile(*configFile)
+	if err != nil {
+		panic(err)
+	}
+	rawConfiguration := Configuration{}
+	json.Unmarshal(file, &rawConfiguration)
+	return rawConfiguration
+}