(#57) Added tests to verify ROI checks

Author: s1hofmann

lib/provider/opencv/image-processor.class.spec.ts

@@ -1,4 +1,5 @@
 import { resolve } from "path";
+import { Region } from "../../region.class";
 import { ImageProcessor } from "./image-processor.class";
 import { ImageReader } from "./image-reader.class";
 
@@ -37,3 +38,45 @@ describe("ImageProcessor", () => {
     expect(mat.empty).toBeFalsy();
   });
 });
+
+describe("ImageProcessor with ROI", () => {
+  it("negative left or top values are updated to 0", async () => {
+    // GIVEN
+    const imageReader = new ImageReader();
+    const imagePath = resolve(__dirname, "./__mocks__/mouse.png");
+    const image = await imageReader.load(imagePath);
+
+    // WHEN
+    const mat = await ImageProcessor.fromImageWithoutAlphaChannel(
+      image,
+      new Region(-100, -100, 10, 10)
+    );
+
+    // THEN
+    expect(image.hasAlphaChannel).toBeFalsy();
+    expect(mat.channels).toEqual(3);
+    expect(mat.rows).toEqual(10);
+    expect(mat.cols).toEqual(10);
+    expect(mat.empty).toBeFalsy();
+  });
+
+  it("values bigger than the input are updated to width and height", async () => {
+    // GIVEN
+    const imageReader = new ImageReader();
+    const imagePath = resolve(__dirname, "./__mocks__/mouse.png");
+    const image = await imageReader.load(imagePath);
+
+    // WHEN
+    const mat = await ImageProcessor.fromImageWithoutAlphaChannel(
+      image,
+      new Region(10, 10, image.width * 2, image.height * 2)
+    );
+
+    // THEN
+    expect(image.hasAlphaChannel).toBeFalsy();
+    expect(mat.channels).toEqual(3);
+    expect(mat.rows).toEqual(image.height - 10);
+    expect(mat.cols).toEqual(image.width - 10);
+    expect(mat.empty).toBeFalsy();
+  });
+});