test: add unit test for MessageProcessor service

__tests__/services/MessageProcessor.test.ts

@@ -0,0 +1,94 @@
+import { expect } from "@jest/globals";
+import { processMessage } from "../../src/services/BlockService/MessageProcessor";
+import { Params } from "../../src/types/Params";
+import { Block } from "../../src/types/Block";
+
+describe("MessageProcessor", () => {
+	let mockParams: Params;
+	let mockBlock: Block;
+
+	// Mock Params with injectMessage function and empty Block
+	beforeEach(() => {
+		mockParams = {
+			injectMessage: jest.fn() as Params["injectMessage"],
+		} as Params;
+
+		mockBlock = {} as Block;
+	});
+
+	// No message in block
+	it("should not inject message if block has no message", async () => {
+		await processMessage(mockBlock, mockParams);
+
+		// Make sure injectMessage was not called
+		expect(mockParams.injectMessage).not.toHaveBeenCalled();
+	});
+
+	// Empty string message
+	it("should not inject message if block message is an empty string", async () => {
+		mockBlock.message = "   ";
+		await processMessage(mockBlock, mockParams);
+
+		// Make sure injectMessage was not called if the message just contains whitespace
+		expect(mockParams.injectMessage).not.toHaveBeenCalled();
+	});
+
+	// Valid string message
+	it("should inject message if block has a non-empty string message", async () => {
+		const message = "Test Message";
+		mockBlock.message = message;
+		await processMessage(mockBlock, mockParams);
+
+		// Make sure injectMessage was called with the correct message
+		expect(mockParams.injectMessage).toHaveBeenCalledWith(message);
+	});
+
+	// Function returning invalid content
+	it("should not inject message if block message is a function returning invalid content", async () => {
+		const functionResult = null;
+		mockBlock.message = jest.fn().mockReturnValue(functionResult);
+
+		await processMessage(mockBlock, mockParams);
+
+		// Make sure injectMessage was not called if function returns null
+		expect(mockParams.injectMessage).not.toHaveBeenCalledWith(functionResult);
+	});
+
+	// Function returning valid content
+	it("should inject message if block message is a function returning valid content", async () => {
+		const functionResult = "Function Result";
+		mockBlock.message = jest.fn().mockReturnValue(functionResult);
+
+		await processMessage(mockBlock, mockParams);
+
+		// Check if the message function was called with correct params
+		expect(mockBlock.message).toHaveBeenCalledWith(mockParams);
+
+		// Make sure injectMessage was called with the function's return value
+		expect(mockParams.injectMessage).toHaveBeenCalledWith(functionResult);
+	});
+
+	// Function returning a promise with invalid content
+	it("should not inject message if block message is a function returning a promise with invalid content", async () => {
+		mockBlock.message = jest.fn().mockResolvedValue(null);
+
+		await processMessage(mockBlock, mockParams);
+
+		// Make sure injectMessage was not called if content is invalid (null)
+		expect(mockParams.injectMessage).not.toHaveBeenCalled();
+	});
+
+	// Function returning a promise with valid content
+	it("should inject message if block message is a function returning a promise with valid content", async () => {
+		const promiseResult = "Async Function Result";
+		mockBlock.message = jest.fn().mockResolvedValue(promiseResult);
+
+		await processMessage(mockBlock, mockParams);
+
+		// Check if the message function was called with correct params
+		expect(mockBlock.message).toHaveBeenCalledWith(mockParams);
+
+		// Make sure injectMessage was called with the resolved promise value
+		expect(mockParams.injectMessage).toHaveBeenCalledWith(promiseResult);
+	});
+});