Add rotating image step

config/example.json

@@ -12,6 +12,13 @@
                 "height": 720,
                 "upscale": false
             }
+        },
+        {
+            "name": "rotate image",
+            "type": 0,
+            "options": {
+                "angle": 90.0
+            }
         }
     ],
     "output": {

pipelines/executable_step.go

@@ -24,3 +24,17 @@ func (s ResizeImageStep) Execute(src image.Image) (image.Image, error) {
 	src = imaging.Resize(src, s.Options.Width, s.Options.Height, imaging.Linear)
 	return src, nil
 }
+
+// Rotate image
+
+type RotateImageStep struct {
+	Step
+	Options struct {
+		Angle float64 `json:"angle"`
+	} `json:"options"`
+}
+
+func (s RotateImageStep) Execute(src image.Image) (image.Image, error) {
+	src = imaging.Rotate(src, s.Options.Angle, image.Black)
+	return src, nil
+}

pipelines/pipeline_test.go

@@ -9,6 +9,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+// pipeline deserialization
+
 func TestImagePipelineDeserialization(t *testing.T) {
 	const Payload string = `{
 		"name": "example pipeline",
@@ -61,6 +63,8 @@ func TestVideoPipelineDeserialization(t *testing.T) {
 	})
 }
 
+// image pipeline steps
+
 func TestResizeImage(t *testing.T) {
 	const Payload string = `{
 		"name": "example pipeline",
@@ -100,6 +104,45 @@ func TestResizeImage(t *testing.T) {
 	})
 }
 
+func TestRotateImage(t *testing.T) {
+	const Payload string = `{
+		"name": "example pipeline",
+		"type": 1,
+		"removeMetadata": false,
+		"steps": [
+			{
+				"name": "rotate image",
+				"type": 1,
+				"options": {
+					"angle": 90.0
+				}
+			}
+		]
+	}`
+	const Bucket string = "pipeline_test_03"
+
+	t.Run("Image rotating is successful", func(t *testing.T) {
+		wd, _ := os.Getwd()
+		pipe := DeserializePipelines([][]byte{[]byte(Payload)})[0]
+
+		storageProvider := storage.GetFileSystemStorageProvider("test", "..")
+
+		_, err := storageProvider.StoreExisting(Bucket, "source.jpg", filepath.Join(wd, "../tests/files/900x900.jpg"))
+		assert.Nil(t, err, "Test file should be readable")
+		assert.FileExists(t, storageProvider.GetPath(Bucket, "source.jpg"))
+
+		dest, err := pipe.Run("source.jpg", Bucket, storageProvider)
+		assert.Nil(t, err)
+		assert.FileExists(t, storageProvider.GetPath(Bucket, dest))
+
+		// clean up
+		os.Remove(storageProvider.GetPath(Bucket, "source.jpg"))
+		os.Remove(storageProvider.GetPath(Bucket, dest))
+	})
+}
+
+// output options
+
 func TestEncodeImageWithJpegQuality(t *testing.T) {
 	const Payload string = `{
 		"name": "example pipeline",
@@ -122,7 +165,7 @@ func TestEncodeImageWithJpegQuality(t *testing.T) {
 	}`
 	const Bucket string = "pipeline_test_02"
 
-	t.Run("Image resizing is successful", func(t *testing.T) {
+	t.Run("Image encoding with jpeg quality is successful", func(t *testing.T) {
 		wd, _ := os.Getwd()
 		pipe := DeserializePipelines([][]byte{[]byte(Payload)})[0]
 

pipelines/step.go

@@ -9,6 +9,7 @@ type StepType int
 
 const (
 	TypeResizeImageStep StepType = iota
+	TypeRotateImageStep
 )
 
 type Step struct {
@@ -19,12 +20,20 @@ type Step struct {
 
 func (s Step) GetExecutable() (IExecutableStep, error) {
 	switch s.GetType() {
+
 	case TypeResizeImageStep:
 		step := ResizeImageStep{}
 		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
 			return nil, err
 		}
 		return step, nil
+
+	case TypeRotateImageStep:
+		step := RotateImageStep{}
+		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
+			return nil, err
+		}
+		return step, nil
 	}
 
 	return nil, errors.New("invalid type")