New CLI flag for comparison customization

README.md

@@ -9,9 +9,15 @@ Locally, you can clone this repository, build it via the Makefile, and run it by
 make build
 ./bin/jsonDiff-darwin json1.json json2.json
 ```
-
 Make sure to use the appropriate binary for your OS. The above example is assuming you are on a Mac.
 
+## Additional CLI flags
+You can also use the `--byteskip` to skip the comparison if the second file has fewer bytes than the first.
+```bash
+./bin/jsonDiff-darwin json1.json json2.json --byteskip
+```
+
+
 # Viewing test coverage
 ```bash
 make tests-coverage && open coverage.html

compare.go

@@ -7,8 +7,9 @@ import (
 )
 
 type JSONDiff struct {
-	File1 File
-	File2 File
+	File1    File
+	File2    File
+	ByteSkip bool
 }
 
 func (j JSONDiff) FindDifferences() string {
@@ -24,6 +25,10 @@ func (j JSONDiff) FindDifferences() string {
 		return "No differences found."
 	}
 
+	if j.ByteSkip && len(j.File2.Bytes) < len(j.File1.Bytes) {
+		return "Second file smaller than first and byteskip enabled"
+	}
+
 	if diff := deep.Equal(j.File1.Map, j.File2.Map); diff != nil {
 		differences := "Differences found:"
 		for _, d := range diff {

compare_test.go

@@ -391,7 +391,7 @@ func TestJSONDiff_FindDifferencesWithSnykShape_Vulnerabilities(t *testing.T) {
 	}
 }
 
-func TestJSONDiff_FindDifference_NoBytes(t *testing.T) {
+func TestJSONDiff_FindDifferences_NoBytes(t *testing.T) {
 	j := JSONDiff{
 		File1: File{
 			Bytes: nil,
@@ -408,7 +408,7 @@ func TestJSONDiff_FindDifference_NoBytes(t *testing.T) {
 	}
 }
 
-func TestJSONDiff_FindDifference_NoMap(t *testing.T) {
+func TestJSONDiff_FindDifferences_NoMap(t *testing.T) {
 	j := JSONDiff{
 		File1: File{
 			Bytes: []byte(`{"key1": "value1"}`),
@@ -424,3 +424,22 @@ func TestJSONDiff_FindDifference_NoMap(t *testing.T) {
 		t.Errorf("JSONDiff.FindDifferences() = %v, want %v", got, "No map defined for File1 and/or File2.")
 	}
 }
+
+func TestJSONDiff_FindDIfferences_ByteSkip(t *testing.T) {
+	j := JSONDiff{
+		File1: File{
+			Bytes: []byte(`{"key1": "value1"}, {"key2": "value2"}`),
+			Map:   map[string]interface{}{"key1": "value1", "key2": "value2"},
+		},
+		File2: File{
+			Bytes: []byte(`{"key1": "value1"}`),
+			Map:   map[string]interface{}{"key1": "value1"},
+		},
+		ByteSkip: true,
+	}
+
+	expected := "Second file smaller than first and byteskip enabled"
+	if got := j.FindDifferences(); got != expected {
+		t.Errorf("JSONDiff.FindDifferences() = %v, want %v", got, expected)
+	}
+}

runner.go

@@ -14,12 +14,11 @@ type Runner struct {
 func (r Runner) Run(reader FileReader) (string, error) {
 	if len(r.Arguments) < 2 {
 		return "", errors.New("please provide two JSON files to compare")
-
 	}
 
-	args := r.Arguments[0:2]
+	fileArgs := r.Arguments[0:2]
 	var files []File
-	for _, arg := range args {
+	for _, arg := range fileArgs {
 		file := File{
 			Reader: reader,
 		}
@@ -35,5 +34,9 @@ func (r Runner) Run(reader FileReader) (string, error) {
 		File2: files[1],
 	}
 
+	if (len(r.Arguments) == 3) && (r.Arguments[2] == "--byteskip") {
+		comparator.ByteSkip = true
+	}
+
 	return comparator.FindDifferences(), nil
 }

runner_test.go

@@ -66,3 +66,19 @@ func TestRunner_Run_InvalidFiles(t *testing.T) {
 		t.Errorf("Expected error, but got did not get one")
 	}
 }
+
+func TestRunner_Run_ByteSkip(t *testing.T) {
+	mockFileReader := MockFileReader{
+		Content: []byte(`{"key1": "value1"}`),
+		Err:     nil,
+	}
+
+	runner := Runner{
+		Arguments: []string{"file1.json", "file2.json", "--byteskip"},
+	}
+
+	_, err := runner.Run(mockFileReader)
+	if err != nil {
+		t.Fatalf("Expected no error, but got %v", err)
+	}
+}