♻️ Export Generator, and switch to WithGenerator Option

generators.go

@@ -6,10 +6,16 @@ import (
 	"github.com/google/uuid"
 )
 
-type generator func() (string, error)
+// Generator is a function that returns the "random" portion of the returned filename.
+// Technically, it doesn't necessarily need to be random, and could be based on time, or a counter,
+// for example.
+type Generator func() (string, error)
 
-func setGenerator(c *config, g generator) {
+// WithGenerator sets the specified generator
+func WithGenerator(g Generator) Option {
+	return func(c *config) {
 		c.generator = g
+	}
 }
 
 func uuidGen() (string, error) {
@@ -20,51 +26,47 @@ func uuidGen() (string, error) {
 	return u.String(), nil
 }
 
-// WithUUID sets a generator that creates a UUIDv4
+// UUID generates a UUIDv4.
-func WithUUID() Option {
+func UUID() Generator {
-	return func(c *config) {
+	return uuidGen
-		setGenerator(c, uuidGen)
-	}
 }
 
 // FileTimestamp is the default format for WithTimestamp and WithTime
 const FileTimestamp string = "2006-01-02_03-05-06-0700"
 
-// WithTimestamp sets a generator that creates a date and time for the current time.
+// Timestamp generates a a date and time for the current time.
-// The format is FileStamp
+// It is formatted accourding to FileTimestamp
-func WithTimestamp() Option {
+func Timestamp() Generator {
-	return WithTimestampFormat(FileTimestamp)
+	return TimestampWithFormat(FileTimestamp)
 }
 
-// WithTimestampFormat sets a generator the creates a date and time for the current time with the supplied format.
+// TimestampWithFormat generates a date and time for the current time with the supplied format.
-func WithTimestampFormat(f string) Option {
+func TimestampWithFormat(f string) Generator {
-	return WithFormattedTime(time.Now(), f)
+	return FormattedTime(time.Now(), FileTimestamp)
 }
 
-// WithTime sets a generator that creates a date and time for the supplied time.
+// Time generates a date and time for the supplied time.
-// The format is FileStamp
+// It is formatted accourding to FileTimestamp
-func WithTime(t time.Time) Option {
+func Time(t time.Time) Generator {
-	return WithFormattedTime(t, FileTimestamp)
+	return FormattedTime(t, FileTimestamp)
 }
 
-// WithFormattedTime sets a generator that creates a date and time for the supplied time with the supplied format.
+// FormattedTime generates a date and time for the supplied time with the supplied format.
-func WithFormattedTime(t time.Time, f string) Option {
+func FormattedTime(t time.Time, f string) Generator {
-	return func(c *config) {
+	return func() (string, error) {
-		setGenerator(c, func() (string, error) {
 		return t.Format(f), nil
-		})
 	}
 }
 
 // FileTimestamp is the default format for WithTimestampUTC and WithTimeUTC
 const FileTimestampNoTZ string = "2006-01-02_03-05-06"
 
-// WithTimestampUTC sets a generator the creates a date and time for the current time in UTC without a timezone in the format.
+// TimestampUTC generates a date and time for the current time in UTC without a timezone in the format.
-func WithTimestampUTC() Option {
+func TimestampUTC() Generator {
-	return WithTimeUTC(time.Now())
+	return TimeUTC(time.Now())
 }
 
-// WithTimeUTC sets a generate that creates a date and time for the supplied time in UTC without a timezone in the format.
+// TimeUTC generates a date and time for the supplied time in UTC without a timezone in the format.
-func WithTimeUTC(t time.Time) Option {
+func TimeUTC(t time.Time) Generator {
-	return WithFormattedTime(t.UTC(), FileTimestampNoTZ)
+	return FormattedTime(t.UTC(), FileTimestampNoTZ)
 }

generators_test.go

@@ -9,11 +9,18 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestWithUUID(t *testing.T) {
+func TestWithGenerator(t *testing.T) {
+	g := func() (string, error) { return "abc", nil }
 	var c config
-	WithUUID()(&c)
+	WithGenerator(g)(&c)
 	st, err := c.generator()
 	assert.NoError(t, err)
+	assert.Equal(t, "abc", st)
+}
+
+func TestUUID(t *testing.T) {
+	st, err := UUID()()
+	assert.NoError(t, err)
 	_, parseErr := uuid.Parse(st)
 	assert.NoError(t, parseErr)
 }
@@ -24,38 +31,32 @@ func (badRead) Read([]byte) (int, error) {
 	return 0, errors.New("sorry")
 }
 
-func TestWithUUIDFail(t *testing.T) {
+func TestUUIDFail(t *testing.T) {
-	var c config
 	uuid.SetRand(badRead{})
 	defer uuid.SetRand(nil)
-	WithUUID()(&c)
+
-	_, err := c.generator()
+	_, err := UUID()()
 	assert.Equal(t, errors.New("sorry"), err)
 }
 
-func TestWithTimestamp(t *testing.T) {
+func TestTimestamp(t *testing.T) {
-	var c config
-	WithTimestamp()(&c)
 	n := time.Now()
-	st, err := c.generator()
+	st, err := Timestamp()()
 	assert.NoError(t, err)
 	assert.Equal(t, n.Format(FileTimestamp), st)
 }
 
-func TestWithTime(t *testing.T) {
+func TestTime(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()
+	st, err := Time(d)()
 	assert.NoError(t, err)
 	assert.Equal(t, d.Format(FileTimestamp), st)
 }
 
-func TestWithTimestampUTC(t *testing.T) {
+func TestTimestampUTC(t *testing.T) {
-	var c config
-	WithTimestampUTC()(&c)
 	n := time.Now()
-	st, err := c.generator()
+	st, err := TimestampUTC()()
 	assert.NoError(t, err)
 	assert.Equal(t, n.UTC().Format(FileTimestampNoTZ), st)
 }

options.go

@@ -7,7 +7,7 @@ type config struct {
 	prefix    string
 	suffix    string
 	extension string
-	generator generator
+	generator Generator
 }
 
 func defaultConf() config {