fix: make --find-renames work with --output=dyff

diff/diff.go

@@ -256,10 +256,8 @@ func doDiff(report *Report, key string, oldContent *manifest.MappingResult, newC
 		}
 	case newContent == nil:
 		changeType = "REMOVE"
-		if oldContent != nil {
-			subjectKind = oldContent.Kind
-		}
-		if !options.StructuredOutput() && oldContent != nil {
+		subjectKind = oldContent.Kind
+		if !options.StructuredOutput() {
 			emptyMapping := &manifest.MappingResult{}
 			diffs = diffMappingResults(oldContent, emptyMapping, options.StripTrailingCR)
 		}

diff/report.go

@@ -110,12 +110,12 @@ func printDyffReport(r *Report, to io.Writer) {
 
 	currentInputFile, newInputFile, _ := ytbx.LoadFiles(currentFile.Name(), newFile.Name())
 
-	report, _ := dyff.CompareInputFiles(
-		currentInputFile, newInputFile,
+	var compareOptions []dyff.CompareOption
+	compareOptions = append(compareOptions,
 		dyff.IgnoreWhitespaceChanges(true),
 		dyff.KubernetesEntityDetection(true),
-		dyff.DetectRenames(true),
 	)
+	report, _ := dyff.CompareInputFiles(currentInputFile, newInputFile, compareOptions...)
 	reportWriter := &dyff.HumanReport{
 		Report:               report,
 		OmitHeader:           true,

diff/report_test.go

@@ -1,8 +1,10 @@
 package diff
 
 import (
+	"bytes"
 	"testing"
 
+	"github.com/aryann/difflib"
 	"github.com/stretchr/testify/require"
 )
 
@@ -34,3 +36,142 @@ func TestLoadFromKey(t *testing.T) {
 		require.Equal(t, expectedTemplateSpec, *templateSpec)
 	}
 }
+
+func TestPrintDyffReport(t *testing.T) {
+	report := &Report{
+		Entries: []ReportEntry{
+			{
+				Key:        "default, nginx, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "MODIFY",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.Common},
+					{Payload: "kind: Deployment", Delta: difflib.Common},
+					{Payload: "metadata:", Delta: difflib.Common},
+					{Payload: "  name: nginx", Delta: difflib.Common},
+					{Payload: "spec:", Delta: difflib.Common},
+					{Payload: "  replicas: 2", Delta: difflib.LeftOnly},
+					{Payload: "  replicas: 3", Delta: difflib.RightOnly},
+				},
+			},
+		},
+	}
+
+	var buf bytes.Buffer
+	printDyffReport(report, &buf)
+
+	output := buf.String()
+	require.NotEmpty(t, output)
+	require.Contains(t, output, "replicas", "Expected dyff output to mention replicas field")
+	require.Contains(t, output, "- 2", "Expected dyff output to show original replicas value")
+	require.Contains(t, output, "+ 3", "Expected dyff output to show updated replicas value")
+}
+
+func TestPrintDyffReportWithAddAndRemove(t *testing.T) {
+	report := &Report{
+		Entries: []ReportEntry{
+			{
+				Key:        "default, old-app, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "REMOVE",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.LeftOnly},
+					{Payload: "kind: Deployment", Delta: difflib.LeftOnly},
+					{Payload: "metadata:", Delta: difflib.LeftOnly},
+					{Payload: "  name: old-app", Delta: difflib.LeftOnly},
+				},
+			},
+			{
+				Key:        "default, new-app, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "ADD",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.RightOnly},
+					{Payload: "kind: Deployment", Delta: difflib.RightOnly},
+					{Payload: "metadata:", Delta: difflib.RightOnly},
+					{Payload: "  name: new-app", Delta: difflib.RightOnly},
+				},
+			},
+		},
+	}
+
+	var buf bytes.Buffer
+	printDyffReport(report, &buf)
+
+	output := buf.String()
+	require.NotEmpty(t, output)
+	require.Contains(t, output, "old-app", "Expected dyff output to show removed resource old-app")
+	require.Contains(t, output, "new-app", "Expected dyff output to show added resource new-app")
+}
+
+func TestPrintDyffReportDoesNotMergeAddRemove(t *testing.T) {
+	addRemoveReport := &Report{
+		Entries: []ReportEntry{
+			{
+				Key:        "default, old-app, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "REMOVE",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.LeftOnly},
+					{Payload: "kind: Deployment", Delta: difflib.LeftOnly},
+					{Payload: "metadata:", Delta: difflib.LeftOnly},
+					{Payload: "  name: old-app", Delta: difflib.LeftOnly},
+				},
+			},
+			{
+				Key:        "default, new-app, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "ADD",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.RightOnly},
+					{Payload: "kind: Deployment", Delta: difflib.RightOnly},
+					{Payload: "metadata:", Delta: difflib.RightOnly},
+					{Payload: "  name: new-app", Delta: difflib.RightOnly},
+				},
+			},
+		},
+	}
+
+	modifyReport := &Report{
+		Entries: []ReportEntry{
+			{
+				Key:        "default, app, Deployment (apps)",
+				Kind:       "Deployment",
+				ChangeType: "MODIFY",
+				Diffs: []difflib.DiffRecord{
+					{Payload: "apiVersion: apps/v1", Delta: difflib.Common},
+					{Payload: "kind: Deployment", Delta: difflib.Common},
+					{Payload: "metadata:", Delta: difflib.Common},
+					{Payload: "  name: app", Delta: difflib.Common},
+					{Payload: "  name: old-app", Delta: difflib.LeftOnly},
+					{Payload: "  name: new-app", Delta: difflib.RightOnly},
+				},
+			},
+		},
+	}
+
+	var addRemoveBuf bytes.Buffer
+	printDyffReport(addRemoveReport, &addRemoveBuf)
+	addRemoveOutput := addRemoveBuf.String()
+
+	var modifyBuf bytes.Buffer
+	printDyffReport(modifyReport, &modifyBuf)
+	modifyOutput := modifyBuf.String()
+
+	require.NotEqual(t, addRemoveOutput, modifyOutput,
+		"ADD+REMOVE output should differ from MODIFY output to verify dyff does not merge them as a rename")
+	require.Contains(t, addRemoveOutput, "old-app")
+	require.Contains(t, addRemoveOutput, "new-app")
+}
+
+func TestPrintDyffReportEmpty(t *testing.T) {
+	report := &Report{
+		Entries: []ReportEntry{},
+	}
+
+	var buf bytes.Buffer
+	printDyffReport(report, &buf)
+
+	output := buf.String()
+	require.Equal(t, "\n", output)
+}