✨ Add time-based generators

generators.go

@@ -1,9 +1,13 @@
 package nomino
 
 import (
+	"time"
+
 	"github.com/google/uuid"
 )
 
+type generator func() (string, error)
+
 func setGenerator(c *config, g generator) {
 	c.generator = g
 }
@@ -21,3 +25,25 @@ func WithUUID() Option {
 		setGenerator(c, uuidGen)
 	}
 }
+
+const FileTimestamp string = "2006-01-02_03-05-06-0700"
+
+func WithTimestamp() Option {
+	return WithTimestampFormat(FileTimestamp)
+}
+
+func WithTimestampFormat(f string) Option {
+	return WithFormattedTime(time.Now(), f)
+}
+
+func WithTime(t time.Time) Option {
+	return WithFormattedTime(t, FileTimestamp)
+}
+
+func WithFormattedTime(t time.Time, f string) Option {
+	return func(c *config) {
+		setGenerator(c, func() (string, error) {
+			return t.Format(f), nil
+		})
+	}
+}

generators_test.go

@@ -3,6 +3,7 @@ package nomino
 import (
 	"errors"
 	"testing"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
@@ -31,3 +32,21 @@ func TestWithUUIDFail(t *testing.T) {
 	_, err := c.generator()
 	assert.Equal(t, errors.New("sorry"), err)
 }
+
+func TestWithTimestamp(t *testing.T) {
+	var c config
+	WithTimestamp()(&c)
+	n := time.Now()
+	st, err := c.generator()
+	assert.NoError(t, err)
+	assert.Equal(t, n.Format(FileTimestamp), st)
+}
+
+func TestWithTime(t *testing.T) {
+	var c config
+	d := time.Date(1986, time.March, 28, 12, 0, 0, 0, time.UTC)
+	WithTime(d)(&c)
+	st, err := c.generator()
+	assert.NoError(t, err)
+	assert.Equal(t, d.Format(FileTimestamp), st)
+}

options.go

@@ -2,8 +2,6 @@ package nomino
 
 import "strings"
 
-type generator func() (string, error)
-
 type config struct {
 	original  string
 	prefix    string