add receiver method ToURL to *Options

options.go

@@ -256,6 +256,53 @@ func ParseURL(sURL string) (*Options, error) {
 	return options, nil
 }
 
+func (opts *Options) ToURL() string {
+	dsn := "postgres://"
+
+	if len(opts.User) > 0 {
+		dsn += opts.User
+
+		if len(opts.Password) > 0 {
+			dsn += ":" + opts.Password
+		}
+
+		dsn += "@"
+	}
+
+	if len(opts.Addr) > 0 {
+		dsn += opts.Addr
+	} else {
+		dsn += "localhost:5432"
+	}
+
+	dsn += "/" + opts.Database
+
+	values := url.Values{}
+
+	if opts.DialTimeout > 0 {
+		values.Add("connect_timeout", strconv.Itoa(int(opts.DialTimeout)/int(time.Second)))
+	}
+
+	if len(opts.ApplicationName) > 0 {
+		values.Add("application_name", opts.ApplicationName)
+	}
+
+	if opts.TLSConfig == nil {
+		values.Add("sslmode", "disable")
+	} else if opts.TLSConfig.InsecureSkipVerify {
+		values.Add("sslmode", "allow")
+	} else if !opts.TLSConfig.InsecureSkipVerify {
+		values.Add("sslmode", "verify-ca")
+	}
+
+	encoded := values.Encode()
+	if len(encoded) > 0 {
+		dsn += "?" + encoded
+	}
+
+	return dsn
+}
+
 func (opt *Options) getDialer() func(context.Context) (net.Conn, error) {
 	return func(ctx context.Context) (net.Conn, error) {
 		return opt.Dialer(ctx, opt.Network, opt.Addr)

options_test.go

@@ -7,6 +7,8 @@ import (
 	"errors"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestParseURL(t *testing.T) {
@@ -261,3 +263,54 @@ func TestParseURL(t *testing.T) {
 		})
 	}
 }
+
+func TestOptions_ToURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		opts     *Options
+		expected string
+	}{
+		{"Empty", &Options{Database: "postgres"}, "postgres://localhost:5432/postgres?sslmode=disable"},
+		{"User", &Options{Database: "postgres", User: "postgres"}, "postgres://postgres@localhost:5432/postgres?sslmode=disable"},
+		{"UserPass", &Options{Database: "postgres", User: "postgres", Password: "password"}, "postgres://postgres:password@localhost:5432/postgres?sslmode=disable"},
+		{"UserPassAddr", &Options{Database: "postgres", User: "postgres", Password: "password", Addr: "somewhere:1234"}, "postgres://postgres:password@somewhere:1234/postgres?sslmode=disable"},
+		{"UserPassAddrAppl", &Options{Database: "postgres", User: "postgres", Password: "password", Addr: "somewhere:1234", ApplicationName: "test"}, "postgres://postgres:password@somewhere:1234/postgres?application_name=test&sslmode=disable"},
+		{"UserPassAddrApplTimeout", &Options{Database: "postgres", User: "postgres", Password: "password", Addr: "somewhere:1234", ApplicationName: "test", DialTimeout: time.Second}, "postgres://postgres:password@somewhere:1234/postgres?application_name=test&connect_timeout=1&sslmode=disable"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			actual := tt.opts.ToURL()
+			assert.Equal(tt.expected, actual)
+
+			_, err := ParseURL(actual)
+			assert.NoError(err)
+		})
+	}
+}
+
+func TestOptions_ToURL_reparsable(t *testing.T) {
+	assert := assert.New(t)
+
+	opts := &Options{
+		Database:        "postgres",
+		User:            "postgres",
+		Password:        "password",
+		Addr:            "somewhere:1234",
+		ApplicationName: "test",
+		DialTimeout:     time.Second,
+	}
+
+	url := opts.ToURL()
+
+	actual, err := ParseURL(url)
+	assert.NoError(err)
+
+	assert.Equal(opts.Database, actual.Database)
+	assert.Equal(opts.User, actual.User)
+	assert.Equal(opts.Password, actual.Password)
+	assert.Equal(opts.Addr, actual.Addr)
+	assert.Equal(opts.ApplicationName, actual.ApplicationName)
+	assert.Equal(opts.DialTimeout, actual.DialTimeout)
+}