added template for output

backvendor/display.go

@@ -0,0 +1,40 @@
+package backvendor
+
+import (
+	"fmt"
+	"io"
+	"text/template"
+)
+
+const defaultTemplate string = "@{{if .Rev}}{{.Rev}}{{end}}{{if .Tag}} ={{.Tag}}{{end}}{{if .Ver}} ~{{.Ver}}{{end}}"
+
+//TemplateError Returned when there's an error creating a template from the arguments
+type TemplateError template.Template
+
+func (t TemplateError) Error(template template.Template) string {
+	return fmt.Sprintf("display: Error creating template from %v", template)
+}
+
+//Display a Reference using a template
+func Display(writer io.Writer, customTemplate string, ref *Reference) error {
+	if customTemplate == "" {
+		tmpl, err := template.New("output").Parse(defaultTemplate)
+		if err != nil {
+			return err
+		}
+		err = tmpl.Execute(writer, ref)
+		if err != nil {
+			return err
+		}
+	} else {
+		tmpl, err := template.New("output").Parse(customTemplate)
+		if err != nil {
+			return err
+		}
+		err = tmpl.Execute(writer, ref)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

backvendor/display_test.go

@@ -0,0 +1,43 @@
+package backvendor
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestDisplay(t *testing.T) {
+	ref := &Reference{Rev: "4309345093405934509", Tag: "v0.0.1", Ver: "v0.0.0.20181785"}
+	var builder strings.Builder
+	err := Display(&builder, "", ref)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestDisplayGarbage(t *testing.T) {
+	ref := &Reference{Rev: "4309345093405934509", Tag: "v0.0.1", Ver: "v0.0.0.20181785"}
+	var builder strings.Builder
+	err := Display(&builder, "{{.", ref)
+	if err == nil {
+		t.Fatal("Should have failed with Error")
+	}
+}
+
+func TestDisplayNoTag(t *testing.T) {
+	ref := &Reference{Rev: "4309345093405934509", Ver: "v0.0.0.20181785"}
+	var builder strings.Builder
+	err := Display(&builder, "", ref)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestDisplayTemplate(t *testing.T) {
+	ref := &Reference{Rev: "4309345093405934509", Ver: "v0.0.0.20181785"}
+	var builder strings.Builder
+	err := Display(&builder, "{{if .Tag}}:{{.Tag}}{{end}}{{if .Ver}}:{{.Ver}}{{end}}", ref)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+}

main.go

@@ -36,6 +36,7 @@ var importPath = flag.String("importpath", "", "top-level import path")
 var depsFlag = flag.Bool("deps", true, "show vendored dependencies")
 var excludeFrom = flag.String("exclude-from", "", "ignore directory entries matching globs in `exclusions`")
 var debugFlag = flag.Bool("debug", false, "show debugging output")
+var template = flag.String("template", "", "go template to use for output with Rev, Tag and Ver")
 
 var errorShown = false
 
@@ -47,18 +48,11 @@ func displayUnknown(name string) {
 	}
 }
 
-func display(name string, ref *backvendor.Reference) {
-	fmt.Print(name)
-	if ref.Rev != "" {
-		fmt.Print("@", ref.Rev)
-	}
-	if ref.Tag != "" {
-		fmt.Print(" =", ref.Tag)
-	}
-	if ref.Ver != "" {
-		fmt.Print(" ~", ref.Ver)
-	}
-	fmt.Print("\n")
+func display(template string, name string, ref *backvendor.Reference) {
+	var builder strings.Builder
+	builder.WriteString(name)
+	backvendor.Display(&builder, template, ref)
+	fmt.Println(builder.String())
 }
 
 func showTopLevel(src *backvendor.GoSource) {
@@ -78,7 +72,7 @@ func showTopLevel(src *backvendor.GoSource) {
 	case backvendor.ErrorVersionNotFound:
 		displayUnknown("*" + main.Root)
 	case nil:
-		display("*"+main.Root, project)
+		display(*template, "*"+main.Root, project)
 	default:
 		log.Fatalf("%s: %s", src.Path, err)
 	}
@@ -105,7 +99,7 @@ func showVendored(src *backvendor.GoSource) {
 		case backvendor.ErrorVersionNotFound:
 			displayUnknown(project.Root)
 		case nil:
-			display(project.Root, vp)
+			display(*template, project.Root, vp)
 		default:
 			log.Fatalf("%s: %s\n", project.Root, err)
 		}