Corrections to the new test cases

patchutils.go

@@ -241,26 +241,32 @@ func MixedModePath(oldSourcePath, newSourcePath string, oldDiff, newDiff io.Read
 	switch {
 	case !oldSourceStat.IsDir() && !newSourceStat.IsDir():
 		// Both sources are files
-		oldD, err := diff.NewFileDiffReader(oldDiff).Read()
+		oldDiffs, err := diff.NewMultiFileDiffReader(oldDiff).ReadAllFiles()
 		if err != nil {
 			return "", fmt.Errorf("parsing oldDiff for %q: %w",
 				oldSourcePath, err)
 		}
-
-		if oldSourcePath != oldD.OrigName {
-			return "", fmt.Errorf("filenames mismatch for oldSourcePath: %q and oldDiff: %q",
-				oldSourcePath, oldD.OrigName)
+		var oldD *diff.FileDiff
+		if len(oldDiffs) > 0 {
+			oldD = oldDiffs[0]
+			if oldSourcePath != oldD.OrigName {
+				return "", fmt.Errorf("filenames mismatch for oldSourcePath: %q and oldDiff: %q",
+					oldSourcePath, oldD.OrigName)
+			}
 		}
 
-		newD, err := diff.NewFileDiffReader(newDiff).Read()
+		newDiffs, err := diff.NewMultiFileDiffReader(newDiff).ReadAllFiles()
 		if err != nil {
 			return "", fmt.Errorf("parsing newDiff for %q: %w",
 				newSourcePath, err)
 		}
-
-		if newSourcePath != newD.OrigName {
-			return "", fmt.Errorf("filenames mismatch for newSourcePath: %q and newDiff: %q",
-				newSourcePath, newD.OrigName)
+		var newD *diff.FileDiff
+		if len(newDiffs) > 0 {
+			newD = newDiffs[0]
+			if newSourcePath != newD.OrigName {
+				return "", fmt.Errorf("filenames mismatch for newSourcePath: %q and newDiff: %q",
+					newSourcePath, newD.OrigName)
+			}
 		}
 
 		resultString, err := mixedModeFilePath(oldSourcePath, newSourcePath, oldD, newD)
@@ -312,6 +318,9 @@ func applyDiff(source string, diffFile *diff.FileDiff) (string, error) {
 			if strings.HasPrefix(line, "+") {
 				newBody = append(newBody, line[1:])
 			} else {
+				if currentOrgSourceI > int32(len(sourceBody)) {
+					return "", errors.New("diff content is out of source content")
+				}
 				if line[1:] != sourceBody[currentOrgSourceI-1] {
 					return "", fmt.Errorf(
 						"line %d in source (%q) and diff (%q): %w",
@@ -525,7 +534,7 @@ func mixedModeDirPath(oldSourcePath, newSourcePath string, oldDiff, newDiff io.R
 	}
 
 	// New files have been added to the new version
-	for filename := range oldFileDiffs {
+	for filename := range newFileDiffs {
 		result += fmt.Sprintf("Only in %s: %s\n", filepath.Dir(filename),
 			filepath.Base(filename))
 	}
@@ -561,18 +570,18 @@ func convertChunksIntoFileDiff(chunks []dbd.Chunk, fileDiff *diff.FileDiff) {
 		NewStartLine:  currentNewI,
 	}
 	// Delete empty chunks in the beginning
-	for len(chunks) > 0 && len(chunks[0].Added) == 0 && len(chunks[0].Deleted) == 0 && len(chunks[0].Equal) == 0 {
+	for len(chunks) > 0 && chunks[0].Added == nil && chunks[0].Deleted == nil && chunks[0].Equal == nil {
 		chunks = chunks[1:]
 	}
 	// Delete empty chunks in the end
 	last := len(chunks) - 1
-	for len(chunks) > 0 && len(chunks[last].Added) == 0 && len(chunks[last].Deleted) == 0 && len(chunks[last].Equal) == 0 {
+	for len(chunks) > 0 && chunks[last].Added == nil && chunks[last].Deleted == nil && chunks[last].Equal == nil {
 		chunks = chunks[:last]
 		last--
 	}
 
 	// If chunks contains only one element with only unchanged lines
-	if len(chunks) == 1 && len(chunks[0].Added) == 0 && len(chunks[0].Deleted) == 0 {
+	if len(chunks) == 1 && chunks[0].Added == nil && chunks[0].Deleted == nil {
 		return
 	}
 
@@ -584,7 +593,7 @@ func convertChunksIntoFileDiff(chunks []dbd.Chunk, fileDiff *diff.FileDiff) {
 	}
 
 	// If first chunk contains only equal lines, we are adding last contextLines to currentHunk
-	if len(chunks[0].Added) == 0 && len(chunks[0].Deleted) == 0 {
+	if chunks[0].Added == nil && chunks[0].Deleted == nil {
 		currentOldI += int32(len(chunks[0].Equal))
 		currentNewI += int32(len(chunks[0].Equal))
 		if len(chunks[0].Equal) > contextLines {
@@ -616,7 +625,7 @@ func convertChunksIntoFileDiff(chunks []dbd.Chunk, fileDiff *diff.FileDiff) {
 			}
 		}
 		// Removing processed equal lines from last chunk
-		chunks[last].Equal = []string{}
+		chunks[last].Equal = nil
 	}
 
 	for _, c := range chunks {
@@ -637,8 +646,8 @@ func convertChunksIntoFileDiff(chunks []dbd.Chunk, fileDiff *diff.FileDiff) {
 				for _, line := range c.Equal[:contextLines] {
 					currentHunkBody = append(currentHunkBody, " "+line)
 				}
-				currentHunk.OrigLines = currentOldI + contextLines + 1 - currentHunk.OrigStartLine
-				currentHunk.NewLines = currentNewI + contextLines + 1 - currentHunk.NewStartLine
+				currentHunk.OrigLines = currentOldI + contextLines - currentHunk.OrigStartLine
+				currentHunk.NewLines = currentNewI + contextLines - currentHunk.NewStartLine
 				currentHunk.Body = []byte(strings.Join(currentHunkBody, "\n") + "\n")
 				fileDiff.Hunks = append(fileDiff.Hunks, currentHunk)
 			}
@@ -653,7 +662,7 @@ func convertChunksIntoFileDiff(chunks []dbd.Chunk, fileDiff *diff.FileDiff) {
 
 			// Clean currentHunkBody
 			currentHunkBody = []string{}
-			for _, line := range c.Equal[len(c.Equal)-contextLines-1:] {
+			for _, line := range c.Equal[len(c.Equal)-contextLines:] {
 				currentHunkBody = append(currentHunkBody, " "+line)
 			}
 

patchutils_test.go

@@ -127,6 +127,14 @@ var mixedModePathFileTests = []struct {
 		resultFile:  "mi_f7_od_nd.diff",
 		wantErr:     false,
 	},
+	{
+		oldSource:   "mixed_old_source/f6_no_changes_to_olddiff.txt",
+		oldDiffFile: "mi_f6_os_od.diff",
+		newSource:   "mixed_new_source/f6_no_changes_to_olddiff.txt",
+		newDiffFile: "mi_f6_ns_nd.diff",
+		resultFile:  "mi_f6_od_nd.diff",
+		wantErr:     false,
+	},
 	{
 		oldSource:   "mixed_old_source",
 		oldDiffFile: "mi_os_od.diff",
@@ -176,19 +184,17 @@ func init() {
 func TestInterDiffMode(t *testing.T) {
 	for _, tt := range interDiffFileTests {
 		t.Run(tt.resultFile, func(t *testing.T) {
-			var fileA, errA = os.Open(tt.diffAFile)
-			var fileB, errB = os.Open(tt.diffBFile)
-
-			if errA != nil {
+			fileA, err := os.Open(tt.diffAFile)
+			if err != nil {
 				t.Errorf("Error in opening %s file.", tt.diffAFile)
 			}
-
-			if errB != nil {
+
+			fileB, err := os.Open(tt.diffBFile)
+			if err != nil {
 				t.Errorf("Error in opening %s file.", tt.diffBFile)
 			}
 
 			correctResult, err := ioutil.ReadFile(tt.resultFile)
-
 			if err != nil {
 				t.Error(err)
 			}
@@ -197,11 +203,13 @@ func TestInterDiffMode(t *testing.T) {
 			var readerB io.Reader = fileB
 
 			currentResult, err := InterDiff(readerA, readerB)
-
+
+			want := normalizeNewlines(correctResult)
+			got := normalizeNewlines([]byte(currentResult))			
 			if (tt.wantErr == nil) && (err == nil) {
-				if d := cmp.Diff(normalizeNewlines(correctResult), normalizeNewlines([]byte(currentResult))); d != "" {
+				if !cmp.Equal(want, got){
 					t.Errorf("File contents mismatch for %s (-want +got):\n%s",
-						tt.resultFile, d)
+						tt.resultFile, cmp.Diff(want, got))
 				}
 			} else if !errors.Is(err, tt.wantErr) {
 				t.Errorf("Interdiff mode for %q: got error %v; want error %v", tt.resultFile, err, tt.wantErr)
@@ -234,10 +242,13 @@ func TestApplyDiff(t *testing.T) {
 			}
 
 			currentResult, err := applyDiff(string(source), d)
+
+			want := normalizeNewlines(correctResult)
+			got := normalizeNewlines([]byte(currentResult))				
 			if (tt.wantErr == nil) && (err == nil) {
-				if d := cmp.Diff(normalizeNewlines(correctResult), normalizeNewlines([]byte(currentResult))); d != "" {
+				if !cmp.Equal(want, got) {
 					t.Errorf("File contents mismatch for %s (-want +got):\n%s",
-						tt.resultFile, d)
+						 tt.resultFile, cmp.Diff(want, got))
 				}
 			} else if !errors.Is(err, tt.wantErr) {
 				t.Errorf("Applying diff for %q: got error %v; want error %v", tt.resultFile, err, tt.wantErr)
@@ -293,10 +304,12 @@ func TestMixedMode(t *testing.T) {
 				t.Errorf("printing result diff for file %q: %v",
 					tt.resultFile, err)
 			}
-
-			if d := cmp.Diff(normalizeNewlines(correctResult), normalizeNewlines([]byte(currentResult))); d != "" {
+
+			want := normalizeNewlines(correctResult)
+			got := normalizeNewlines([]byte(currentResult))				
+			if !cmp.Equal(want, got) {
 				t.Errorf("File contents mismatch for %s (-want +got):\n%s",
-					tt.resultFile, d)
+					 tt.resultFile, cmp.Diff(want, got))
 			}
 		})
 	}
@@ -335,10 +348,12 @@ func TestMixedModeFile(t *testing.T) {
 			if err != nil {
 				t.Errorf("Mixed mode for %q: got error %v; want error nil", tt.resultFile, err)
 			}
-
-			if d := cmp.Diff(normalizeNewlines(correctResult), normalizeNewlines([]byte(currentResult))); d != "" {
+
+			want := normalizeNewlines(correctResult)
+			got := normalizeNewlines([]byte(currentResult))	
+			if !cmp.Equal(want, got) {
 				t.Errorf("File contents mismatch for %s (-want +got):\n%s",
-					tt.resultFile, d)
+					 tt.resultFile, cmp.Diff(want, got))
 			}
 		})
 	}
@@ -370,10 +385,12 @@ func TestMixedModePath(t *testing.T) {
 				if err != nil {
 					t.Errorf("MixedModePath for %q: got error %v; want error nil", tt.resultFile, err)
 				}
-
-				if d := cmp.Diff(normalizeNewlines(correctResult), normalizeNewlines([]byte(currentResult))); d != "" {
+
+				want := normalizeNewlines(correctResult)
+				got := normalizeNewlines([]byte(currentResult))	
+				if !cmp.Equal(want, got) {
 					t.Errorf("File contents mismatch for %s (-want +got):\n%s",
-						tt.resultFile, d)
+						 tt.resultFile, cmp.Diff(want, got))
 				}
 			}
 		})

test_examples/mi_f6_ns_nd.diff

@@ -5,7 +5,5 @@
  Do-do-do-do ah-ah-ah, do-do-do-do, Cities of Gold.
  Do-do-do-do, Cities of Gold. Ah-ah-ah-ah-ah…
 -some day we will find The Cities of Gold.
-\ No newline at end of file
 +some day we will find The Cities of Gold.
 +some day we will find The Cities of Silver.
-\ No newline at end of file

test_examples/mi_f6_od_nd.diff

@@ -1,18 +1,12 @@
---- mixed_updated_old_source/f6_no_changes_to_olddiff.txt	2020-10-30 11:12:55.910740594 +0000
+--- mixed_old_source/f6_no_changes_to_olddiff.txt
 +++ mixed_updated_new_source/f6_no_changes_to_olddiff.txt	2020-10-30 11:32:22.322300642 +0000
-@@ -1,5 +1,6 @@
+@@ -1,4 +1,5 @@
  Text is generated in https://vole.wtf/text-generator/
  Children of the sun,
 +Children of the sun,
  see your time has just begun,
  searching for your ways,
- through adventures every day.
-@@ -11,4 +12,5 @@
- Ah-ah-ah-ah-ah… some day we will find The Cities of Gold.
- Do-do-do-do ah-ah-ah, do-do-do-do, Cities of Gold.
+@@ -13,2 +14,3 @@
  Do-do-do-do, Cities of Gold. Ah-ah-ah-ah-ah…
--some day we will find The Cities of Gold.
-\ No newline at end of file
-+some day we will find The Cities of Gold.
+ some day we will find The Cities of Gold.
 +some day we will find The Cities of Silver.
-\ No newline at end of file

test_examples/mi_nd_od.diff

@@ -4,14 +4,13 @@ Only in mixed_updated_new_source: f3_deleted_in_olddiff.txt
 +++ mixed_old_source/f5_same_in_both_sources.txt
 --- mixed_updated_new_source/f6_no_changes_to_olddiff.txt
 +++ mixed_old_source/f6_no_changes_to_olddiff.txt
-@@ -1,6 +1,5 @@
+@@ -1,5 +1,4 @@
  Text is generated in https://vole.wtf/text-generator/
  Children of the sun,
 -Children of the sun,
  see your time has just begun,
  searching for your ways,
 @@ -14,3 +13,2 @@
- Do-do-do-do ah-ah-ah, do-do-do-do, Cities of Gold.
  Do-do-do-do, Cities of Gold. Ah-ah-ah-ah-ah…
  some day we will find The Cities of Gold.
 -some day we will find The Cities of Silver.
@@ -42,3 +41,4 @@ Only in mixed_updated_new_source: f3_deleted_in_olddiff.txt
 -flowers, rivers, sand and sea,
  snowflakes and the stars are free.
  Every day and night,
+Only in mixed_updated_old_source: f2_added_in_old_diff.txt

test_examples/mi_od_nd.diff

@@ -4,14 +4,13 @@ Only in mixed_updated_new_source: f3_deleted_in_olddiff.txt
 +++ mixed_new_source/f5_same_in_both_sources.txt
 --- mixed_old_source/f6_no_changes_to_olddiff.txt
 +++ mixed_updated_new_source/f6_no_changes_to_olddiff.txt
-@@ -1,5 +1,6 @@
+@@ -1,4 +1,5 @@
  Text is generated in https://vole.wtf/text-generator/
  Children of the sun,
 +Children of the sun,
  see your time has just begun,
  searching for your ways,
 @@ -13,2 +14,3 @@
- Do-do-do-do ah-ah-ah, do-do-do-do, Cities of Gold.
  Do-do-do-do, Cities of Gold. Ah-ah-ah-ah-ah…
  some day we will find The Cities of Gold.
 +some day we will find The Cities of Silver.
@@ -43,4 +42,3 @@ Only in mixed_updated_new_source: f3_deleted_in_olddiff.txt
  snowflakes and the stars are free.
  Every day and night,
 Only in mixed_updated_old_source: f2_added_in_old_diff.txt
-Only in mixed_updated_old_source: f2_added_in_old_diff.txt