omit the first line continuation if tuple contains just a few entries; also closes #9

Author: dmgk

main.go

@@ -28,10 +28,10 @@ func main() {
 	parser := tuple.NewParser(flagPackagePrefix, flagOffline)
 	tuples, errors := parser.Load(args[0])
 	if len(tuples) != 0 {
-		fmt.Println(tuples)
+		fmt.Print(tuples)
 	}
 	if errors != nil {
-		fmt.Println(errors)
+		fmt.Print(errors)
 	}
 }
 

tuple/tuple.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"reflect"
 	"regexp"
 	"sort"
 	"strings"
@@ -112,45 +111,37 @@ func (tt ByAccountAndProject) Less(i, j int) bool {
 	return tt[i].String() < tt[j].String()
 }
 
+// If tuple contains more than largeLimit entries, start tuple list on the new line for easier sorting/editing.
+// Otherwise omit the first line continuation for more compact representation.
+const largeLimit = 3
+
 func (tt Tuples) String() string {
 	if len(tt) == 0 {
 		return ""
 	}
 
-	bufs := make(map[reflect.Type]*bytes.Buffer)
-
+	tm := make(map[Source][]string)
 	for _, t := range tt {
-		st := reflect.TypeOf(t.Source)
-		if st == nil {
-			panic(fmt.Sprintf("unknown source in tuple: %v", t))
-		}
-
-		buf, ok := bufs[st]
-		if !ok {
-			buf = &bytes.Buffer{}
-			bufs[st] = buf
-		}
-
-		var eol string
-		if buf.Len() == 0 {
-			buf.WriteString(fmt.Sprintf("%s=\t", t.Source.VarName()))
-			eol = `\`
-		}
-		s := t.String()
-		if strings.HasPrefix(s, "#") {
-			eol = ""
-		} else if eol == "" {
-			eol = ` \`
-		}
-		buf.WriteString(fmt.Sprintf("%s\n\t\t%s", eol, s))
+		tm[t.Source] = append(tm[t.Source], t.String())
 	}
 
 	var ss []string
-	for _, buf := range bufs {
-		s := buf.String()
-		if len(s) > 0 {
-			ss = append(ss, s)
+	for s, ee := range tm {
+		buf := bytes.NewBufferString(fmt.Sprintf("%s=\t", s.VarName()))
+		large := len(ee) > largeLimit
+		if large {
+			buf.WriteString("\\\n")
+		}
+		for i := 0; i < len(ee); i += 1 {
+			if i > 0 || large {
+				buf.WriteString("\t\t")
+			}
+			buf.WriteString(ee[i])
+			if i < len(ee)-1 {
+				buf.WriteString(" \\\n")
+			}
 		}
+		ss = append(ss, buf.String())
 	}
 	sort.Sort(sort.StringSlice(ss))
 

tuple/tuple_online_test.go

@@ -12,8 +12,7 @@ func TestUniqueProjectAndTag(t *testing.T) {
 # github.com/json-iterator/go v1.1.7
 # github.com/ugorji/go v1.1.7`
 
-	expected := `GH_TUPLE=	\
-		json-iterator:go:v1.1.7:json_iterator_go/vendor/github.com/json-iterator/go \
+	expected := `GH_TUPLE=	json-iterator:go:v1.1.7:json_iterator_go/vendor/github.com/json-iterator/go \
 		ugorji:go:23ab95ef5dc3:ugorji_go/vendor/github.com/ugorji/go
 `
 

tuple/tuple_test.go

@@ -186,8 +186,7 @@ gitlab.com/gitlab-org/gitaly-proto/go/gitalypb
 		ugorji:go:e444a5086c43:ugorji_go/vendor/github.com/ugorji/go \
 		user:pkg:v3.0.0:user_pkg/vendor/gopkg.in/user/pkg.v3
 
-GL_TUPLE=	\
-		gitlab-org:gitaly-proto:v1.32.0:gitlab_org_gitaly_proto/vendor/gitlab.com/gitlab-org/gitaly-proto \
+GL_TUPLE=	gitlab-org:gitaly-proto:v1.32.0:gitlab_org_gitaly_proto/vendor/gitlab.com/gitlab-org/gitaly-proto \
 		gitlab-org:labkit:0c3fc7cdd57c:gitlab_org_labkit/vendor/gitlab.com/gitlab-org/labkit
 		# Mirrors for the following packages are not currently known, please look them up and handle these tuples manually:
 		#	::v1.0.0:group_name/vendor/another.vanity_url.org/account/project
@@ -226,6 +225,6 @@ func TestUniqueGroups(t *testing.T) {
 	}
 	out := tt.String()
 	if out != expected {
-		t.Errorf("expected output %s, got %s", expected, out)
+		t.Errorf("expected output\n%s, got\n%s", expected, out)
 	}
 }