Improve output description for SetRequest diff. (#796)

Author: wenovus

gnmidiff/README.md

@@ -6,8 +6,8 @@ $ go install ./gnmidiff
 $ gnmidiff setrequest cmd/demo/setrequest.textproto cmd/demo/setrequest2.textproto
 
 SetRequestIntentDiff(-A, +B):
--------- deletes --------
-+ /network-instances/network-instance[name=VrfBlue]: deleted
+-------- deletes/replaces --------
++ /network-instances/network-instance[name=VrfBlue]: deleted or replaced only in B
 -------- updates --------
 m /system/config/hostname:
   - "violetsareblue"

gnmidiff/diff.go

@@ -92,6 +92,12 @@ type Format struct {
 	aName string
 	// bName is an optional custom name for B in the diff.
 	bName string
+	// deleteTitle is an optional custom name when titling the diff section
+	// with delete paths.
+	deleteTitle string
+	// deleteDesc is an optional custom description when describing a
+	// delete path in the diff.
+	deleteDesc string
 }
 
 func formatJSONValue(value interface{}) interface{} {
@@ -115,11 +121,17 @@ func (diff StructuredDiff) Format(f Format) string {
 	if f.bName == "" {
 		f.bName = "B"
 	}
+	if f.deleteTitle == "" {
+		f.deleteDesc = "deletes"
+	}
+	if f.deleteDesc == "" {
+		f.deleteTitle = "deleted only in %s"
+	}
 	b.WriteString(fmt.Sprintf("%s(-%s, +%s):\n", f.title, f.aName, f.bName))
 
 	deleteDiff := diff.DeleteDiff.format(f)
 	if deleteDiff != "" {
-		b.WriteString("-------- deletes --------\n")
+		b.WriteString(fmt.Sprintf("-------- %s --------\n", f.deleteTitle))
 		b.WriteString(deleteDiff)
 		b.WriteString("-------- updates --------\n")
 	}
@@ -177,7 +189,15 @@ func (diff DeleteDiff) format(f Format) string {
 		}
 		sort.Strings(paths)
 		for _, path := range paths {
-			b.WriteString(fmt.Sprintf("%c %s: deleted\n", symbol, path))
+			b.WriteString(fmt.Sprintf("%c %s: "+f.deleteDesc, symbol, path))
+			switch symbol {
+			case '-':
+				b.WriteString(fmt.Sprintf(" only in %s\n", f.aName))
+			case '+':
+				b.WriteString(fmt.Sprintf(" only in %s\n", f.bName))
+			default:
+				b.WriteString("\n")
+			}
 		}
 	}
 

gnmidiff/setrequest.go

@@ -37,6 +37,8 @@ func (diff SetRequestIntentDiff) Format(f Format) string {
 	f.title = "SetRequestIntentDiff"
 	f.aName = "A"
 	f.bName = "B"
+	f.deleteTitle = "deletes/replaces"
+	f.deleteDesc = "deleted or replaced"
 	return StructuredDiff(diff).Format(f)
 }
 

gnmidiff/setrequest_test.go

@@ -80,9 +80,9 @@ func TestSetRequestDiffFormat(t *testing.T) {
 		},
 		inFormat: Format{},
 		want: `SetRequestIntentDiff(-A, +B):
--------- deletes --------
-- /interfaces/interface[name=eth1]: deleted
-+ /interfaces/interface[name=eth2]: deleted
+-------- deletes/replaces --------
+- /interfaces/interface[name=eth1]: deleted or replaced only in A
++ /interfaces/interface[name=eth2]: deleted or replaced only in B
 -------- updates --------
 - /interfaces/interface[name=eth1]/config/name: "eth1"
 - /interfaces/interface[name=eth1]/name: "eth1"
@@ -146,10 +146,10 @@ m /interfaces/interface[name=eth0]/subinterfaces/subinterface[index=0]/state/nam
 			Full: true,
 		},
 		want: `SetRequestIntentDiff(-A, +B):
--------- deletes --------
-  /interfaces/interface[name=eth0]: deleted
-- /interfaces/interface[name=eth1]: deleted
-+ /interfaces/interface[name=eth2]: deleted
+-------- deletes/replaces --------
+  /interfaces/interface[name=eth0]: deleted or replaced
+- /interfaces/interface[name=eth1]: deleted or replaced only in A
++ /interfaces/interface[name=eth2]: deleted or replaced only in B
 -------- updates --------
   /interfaces/interface[name=eth0]/config/description: "I am an eth port"
   /interfaces/interface[name=eth0]/config/name: "eth0"