(#547) New matcher toHaveColor that verifies pixel colors on screen

lib/expect/matchers/toHaveColor.function.spec.ts

@@ -0,0 +1,66 @@
+import { RGBA, screen } from "../../../index";
+import { Point } from "../../point.class";
+import { mockPartial } from "sneer";
+import { toHaveColor } from "./toHaveColor.function";
+
+// jest.mock("jimp", () => {});
+
+const targetPoint = new Point(400, 400);
+
+describe(".toHaveColor", () => {
+  it("should succeed when screen pixel has the correct RGBA value", async () => {
+    // GIVEN
+    screen.colorAt = mockPartial(() => {
+      return new RGBA(0, 0, 0, 0);
+    });
+
+    // WHEN
+    const result = await toHaveColor(targetPoint, new RGBA(0, 0, 0, 0));
+
+    // THEN
+    expect(result.pass).toBeTruthy();
+  });
+
+  it("should fail when the screen pixel has the incorrect RGBA value", async () => {
+    // GIVEN
+    screen.colorAt = mockPartial(() => {
+      return new RGBA(255, 0, 5, 0);
+    });
+
+    // WHEN
+    const result = await toHaveColor(targetPoint, new RGBA(0, 0, 0, 0));
+
+    // THEN
+    expect(result.pass).toBeFalsy();
+  });
+
+  it("should succeed when the screen pixel has the correct RGBA value", async () => {
+    // GIVEN
+    screen.colorAt = mockPartial(() => {
+      return new RGBA(0, 0, 0, 0);
+    });
+    expect.extend({
+      toHaveColor,
+    });
+
+    // WHEN
+
+    // THEN
+    await expect(targetPoint).toHaveColor(new RGBA(0, 0, 0, 0));
+  });
+
+  it("should succeed when the screen pixel has the incorrect RGBA value", async () => {
+    // GIVEN
+    screen.colorAt = mockPartial(() => {
+      return new RGBA(255, 0, 5, 0);
+    });
+    expect.extend({
+      toHaveColor,
+    });
+
+    // WHEN
+
+    // THEN
+    await expect(targetPoint).not.toHaveColor(new RGBA(0, 0, 0, 0));
+  });
+});

lib/expect/matchers/toHaveColor.function.ts

@@ -0,0 +1,19 @@
+import { Point, RGBA, screen } from "../../../index";
+
+export const toHaveColor = async (received: Point, needle: RGBA) => {
+  const color = await screen.colorAt(received);
+  const match = color.toHex() === needle.toHex();
+  if (match) {
+    return {
+      message: () =>
+        `Expected pixel ${received.toString()} not to to have color ${needle.toHex()}`,
+      pass: true,
+    };
+  } else {
+    return {
+      message: () =>
+        `Expected pixel ${received.toString()} to have color ${needle.toHex()} but is ${color.toHex()}`,
+      pass: false,
+    };
+  }
+};