Add unit test for crop

Author: Doug Toppin

source/image-handler/test/image-handler/crop.spec.ts

@@ -10,16 +10,21 @@ import { ImageEdits, StatusCodes } from "../../lib";
 const s3Client = new S3();
 const rekognitionClient = new Rekognition();
 
+// base64 encoded images
+const image_png_1x1 = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==";
+const image_png_white_5x5 = "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFAQAAAAClFBtIAAAABGdBTUEAALGPC/xhBQAAACBjSFJNAAB6JgAAgIQAAPoAAACA6AAAdTAAAOpgAAA6mAAAF3CculE8AAAAAmJLR0QAAd2KE6QAAAAHdElNRQfnAxYODhUMhxdmAAAADElEQVQI12P4wQCFABhCBNn4i/hQAAAAJXRFWHRkYXRlOmNyZWF0ZQAyMDIzLTAzLTIyVDE0OjE0OjIxKzAwOjAwtK8ALAAAACV0RVh0ZGF0ZTptb2RpZnkAMjAyMy0wMy0yMlQxNDoxNDoyMSswMDowMMXyuJAAAAAASUVORK5CYII=";
+const image_png_white_1x1 = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAACXBIWXMAAAsTAAALEwEAmpwYAAAADElEQVR4nGP4//8/AAX+Av4N70a4AAAAAElFTkSuQmCC";
+
 describe("crop", () => {
   it("Should pass if a cropping area value is out of bounds", async () => {
     // Arrange
     const originalImage = Buffer.from(
-      "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==",
+      image_png_1x1,
       "base64"
     );
     const image = sharp(originalImage, { failOnError: false }).withMetadata();
     const edits: ImageEdits = {
-      crop: { left: 0, right: 0, width: 100, height: 100 },
+      crop: { left: 0, top: 0, width: 100, height: 100 },
     };
 
     // Act
@@ -36,4 +41,69 @@ describe("crop", () => {
       });
     }
   });
+
+  // confirm that crops perform as expected
+  it("Should pass with a standard crop", async () => {
+    // 5x5 png
+    const originalImage = Buffer.from(
+      image_png_white_5x5,
+      "base64"
+    );
+    const image = sharp(originalImage, { failOnError: false }).withMetadata();
+    const edits: ImageEdits = {
+      crop: { left: 0, top: 0, width: 1, height: 1 },
+    };
+
+    // crop an image and compare with the result expected
+    try {
+      const imageHandler = new ImageHandler(s3Client, rekognitionClient);
+      const result = await imageHandler.applyEdits(image, edits, false);
+      const resultBuffer = await result.toBuffer();
+      expect(resultBuffer).toEqual(
+        Buffer.from(
+          image_png_white_1x1,
+          "base64"
+        )
+      );
+    } catch (error) {
+      console.log(error);
+      throw (error);
+    }
+  });
+
+  // confirm that an invalid attribute sharp crop request containing *right* rather than *top* returns as a cropping error,
+  // note that this only confirms the behavior of the image-handler in this case,
+  // it is not an accurate description of the actual error
+  it("Should fail with an invalid crop request", async () => {
+    // 5x5 png
+    const originalImage = Buffer.from(
+      image_png_white_5x5,
+      "base64"
+    );
+    const image = sharp(originalImage, { failOnError: false }).withMetadata();
+    const edits: ImageEdits = {
+      crop: { left: 0, right: 0, width: 1, height: 1 },
+    };
+
+    // crop an image and compare with the result expected
+    try {
+      const imageHandler = new ImageHandler(s3Client, rekognitionClient);
+      const result = await imageHandler.applyEdits(image, edits, false);
+      const resultBuffer = await result.toBuffer();
+      expect(resultBuffer).toEqual(
+        Buffer.from(
+          image_png_white_1x1,
+          "base64"
+        )
+      );
+    } catch (error) {
+      // Assert
+      expect(error).toMatchObject({
+        status: StatusCodes.BAD_REQUEST,
+        code: "Crop::AreaOutOfBounds",
+        message:
+          "The cropping area you provided exceeds the boundaries of the original image. Please try choosing a correct cropping value.",
+      });
+    }
+  });
 });