Add row printer

main.go → fp.go

@@ -11,7 +11,6 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-	"sort"
 )
 
 // DigestGroup hashes a file for a given path
@@ -41,18 +40,6 @@ func DigestGroup(hg map[string]hash.Hash, loc string) (map[string]string, error)
 	return out, nil
 }
 
-func writeTo(values map[string]string, w io.Writer) {
-	keys := make([]string, 0, len(values))
-	for k := range values {
-		keys = append(keys, k)
-	}
-	sort.Strings(keys)
-
-	for _, name := range keys {
-		fmt.Fprintf(w, "%s: %s\n", name, values[name])
-	}
-}
-
 // ReadFileInfo gets the abs path and follows the link
 func ReadFileInfo(path string) (string, os.FileInfo, error) {
 	abs, err := filepath.Abs(path)
@@ -98,7 +85,13 @@ func main() {
 		os.Exit(1)
 	}
 
-	fmt.Fprintf(fd, "PATH: %s\n", abs)
+	rr := NewRowRender(os.Stdout)
+	if fi.IsDir() {
+		rr.AddRow("DIR", abs)
+	} else {
+		rr.AddRow("PATH", abs)
+	}
+
 	if *verbose && !fi.IsDir() {
 		hg := make(map[string]hash.Hash)
 		hg["MD5"] = md5.New()
@@ -110,7 +103,8 @@ func main() {
 			fmt.Fprintf(fd, "Cannot digest group: %v", err)
 			os.Exit(1)
 		}
-		writeTo(values, fd)
+		rr.AddRowMap(values)
 	}
 
+	rr.Render()
 }

printer.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"sort"
+)
+
+// RowRenderer render the row to a file descriptor.
+type RowRenderer interface {
+	// AddRow adds a row to writer.
+	AddRow(field, value string)
+	// AddRowMap appends the row by map input.
+	AddRowMap(values map[string]string)
+	// Render the rows.
+	Render()
+}
+
+// NewRowRender creates the printer.
+func NewRowRender(w io.Writer) RowRenderer {
+	return &pw{w, make([][]string, 0)}
+}
+
+type pw struct {
+	w    io.Writer
+	rows [][]string
+}
+
+// AddRow adds a row to writer.
+func (p *pw) AddRow(field, value string) {
+	r := []string{field, value}
+	p.rows = append(p.rows, r)
+}
+
+// AddRowMap appends the row from map. It sorts the map by default.
+func (p *pw) AddRowMap(values map[string]string) {
+	keys := make([]string, 0, len(values))
+	for k := range values {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for _, name := range keys {
+		r := []string{name, values[name]}
+		p.rows = append(p.rows, r)
+	}
+
+}
+
+// Render the rows to output
+func (p *pw) Render() {
+	for _, l := range p.rows {
+		fmt.Fprintf(p.w, "%s: %s\n", l[0], l[1])
+	}
+}

printer_test.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestRowPrinter(t *testing.T) {
+	buf := new(bytes.Buffer)
+	pw := &pw{buf, make([][]string, 0)}
+	pw.AddRow("foo", "bar")
+	pw.Render()
+
+	got := buf.String()
+	want := "foo: bar\n"
+
+	if got != want {
+		t.Errorf("Got: %s - want: %s", buf, want)
+	}
+
+}