Wrote test cases for FunctionProcessor (#181)

__tests__/services/FunctionProcessor.test.ts

@@ -0,0 +1,60 @@
+import { processFunction } from "../../src/services/BlockService/FunctionProcessor";
+import { Block } from "../../src/types/Block";
+import { Params } from "../../src/types/Params";
+
+describe('processFunction', () => {
+    let params: Params;
+
+    beforeEach(() => {
+        params = {
+            userInput: "",
+            currPath: null,
+            prevPath: null,
+            goToPath: jest.fn(),
+            setTextAreaValue: jest.fn(),
+            injectMessage: jest.fn(),
+            streamMessage: jest.fn(),
+            removeMessage: jest.fn(),
+            endStreamMessage: jest.fn(),
+            showToast: jest.fn(),
+            dismissToast: jest.fn(),
+            openChat: jest.fn()
+        };
+    });
+
+    it('should return undefined if block has no function', async () => {
+        const block: Block = { function: undefined };
+
+        const result = await processFunction(block, params);
+
+        expect(result).toBeUndefined();
+    });
+
+    it('should return the result of the function if it is not a promise', async () => {
+        const block: Block = { function: jest.fn(() => 'result') };
+
+        const result = await processFunction(block, params);
+
+        expect(result).toBe('result');
+    });
+
+    it('should return the resolved value of the function if it is a promise', async () => {
+        const block: Block = { function: jest.fn(() => Promise.resolve('resolved value')) };
+
+        const result = await processFunction(block, params);
+
+        expect(result).toBe('resolved value');
+    });
+
+    it('should handle function throwing an error', async () => {
+        const block: Block = { function: jest.fn(() => { throw new Error('error'); }) };
+
+        await expect(processFunction(block, params)).rejects.toThrow('error');
+    });
+
+    it('should handle function returning a rejected promise', async () => {
+        const block: Block = { function: jest.fn(() => Promise.reject('rejected value')) };
+
+        await expect(processFunction(block, params)).rejects.toBe('rejected value');
+    });
+});