import { TranscriptService } from "../transcript.service";
import { CacheService } from "../cache.service";
import { fetchTranscript } from "youtube-transcript-plus";
// Mock the dependencies
jest.mock("../cache.service");
jest.mock("youtube-transcript-plus", () => ({
fetchTranscript: jest.fn(),
}));
const mockFetchTranscript = fetchTranscript as jest.Mock;
const MockCacheService = CacheService;
describe("TranscriptService", () => {
let transcriptService: TranscriptService;
let cacheService: jest.Mocked<CacheService>;
beforeEach(() => {
// Reset mocks before each test
jest.clearAllMocks();
// Provide a mock implementation of CacheService
cacheService = new MockCacheService(null);
transcriptService = new TranscriptService(cacheService);
});
describe("getTranscriptSegments", () => {
const mockSubtitles = [
{ start: "0", dur: "5", text: "This is the hook." },
{ start: "40", dur: "5", text: "This is the middle." },
{ start: "80", dur: "5", text: "This is the outro." },
];
it("should return a { hook, outro } object for format 'key_segments'", async () => {
// @ts-ignore
transcriptService.fetchAndCacheRawTranscript = jest
.fn()
.mockResolvedValue(mockSubtitles);
const result = await transcriptService.getTranscriptSegments(
"video1",
"en",
"key_segments"
);
expect(result).toEqual({
hook: "This is the hook.",
outro: "This is the outro.",
});
});
it("should return a { transcript } object for format 'full_text'", async () => {
// @ts-ignore
transcriptService.fetchAndCacheRawTranscript = jest
.fn()
.mockResolvedValue(mockSubtitles);
const result = await transcriptService.getTranscriptSegments(
"video1",
"en",
"full_text"
);
expect(result).toEqual({
transcript: "This is the hook. This is the middle. This is the outro.",
});
});
it("should return null if the transcript is empty", async () => {
// @ts-ignore
transcriptService.fetchAndCacheRawTranscript = jest
.fn()
.mockResolvedValue([]);
const result = await transcriptService.getTranscriptSegments("video1");
expect(result).toBeNull();
});
it("should return null if the transcript is null", async () => {
// @ts-ignore
transcriptService.fetchAndCacheRawTranscript = jest
.fn()
.mockResolvedValue(null);
const result = await transcriptService.getTranscriptSegments("video1");
expect(result).toBeNull();
});
it("should default to format 'key_segments' and lang 'en'", async () => {
// @ts-ignore
transcriptService.fetchAndCacheRawTranscript = jest
.fn()
.mockResolvedValue(mockSubtitles);
const result = await transcriptService.getTranscriptSegments("video1");
expect(result).toEqual({
hook: "This is the hook.",
outro: "This is the outro.",
});
expect(transcriptService.fetchAndCacheRawTranscript).toHaveBeenCalledWith(
"video1",
"en"
);
});
});
describe("fetchAndCacheRawTranscript", () => {
const mockApiResponse = [{ text: "hello world", offset: 0, duration: 1 }];
const expectedSubtitles = [{ text: "hello world", start: "0", dur: "1" }];
const videoId = "video1";
const lang = "en";
const cacheKey = "someCacheKey";
beforeEach(() => {
cacheService.createOperationKey.mockReturnValue(cacheKey);
});
it("should call fetchTranscript when cache is empty and return mapped data", async () => {
cacheService.getOrSet.mockImplementation(async (key, operation) =>
operation()
);
mockFetchTranscript.mockResolvedValue(mockApiResponse);
// @ts-ignore
const result = await transcriptService.fetchAndCacheRawTranscript(
videoId,
lang
);
expect(cacheService.getOrSet).toHaveBeenCalledWith(
cacheKey,
expect.any(Function),
expect.any(Number),
expect.any(String),
expect.any(Object)
);
expect(mockFetchTranscript).toHaveBeenCalledWith(videoId, { lang });
expect(result).toEqual(expectedSubtitles);
});
it("should return an empty array if fetchTranscript call fails", async () => {
cacheService.getOrSet.mockImplementation(async (key, operation) =>
operation()
);
mockFetchTranscript.mockRejectedValue(new Error("Fetch failed"));
// @ts-ignore
const result = await transcriptService.fetchAndCacheRawTranscript(
videoId,
lang
);
expect(result).toEqual([]);
});
it("should return data from cache without calling fetchTranscript", async () => {
cacheService.getOrSet.mockResolvedValue(expectedSubtitles);
// @ts-ignore
const result = await transcriptService.fetchAndCacheRawTranscript(
videoId,
lang
);
expect(cacheService.getOrSet).toHaveBeenCalledWith(
cacheKey,
expect.any(Function),
expect.any(Number),
expect.any(String),
expect.any(Object)
);
expect(mockFetchTranscript).not.toHaveBeenCalled();
expect(result).toEqual(expectedSubtitles);
});
});
describe("extractHook and extractOutro", () => {
describe("extractHook", () => {
it("should return text from the first 40 seconds for a long video", () => {
const subtitles = [
{ start: "10", dur: "5", text: "Part 1." },
{ start: "30", dur: "5", text: "Part 2." },
{ start: "50", dur: "5", text: "Part 3." },
];
// @ts-ignore
const result = transcriptService.extractHook(subtitles);
expect(result).toBe("Part 1. Part 2.");
});
it("should return the entire text for a video shorter than 40 seconds", () => {
const subtitles = [
{ start: "5", dur: "5", text: "Short video." },
{ start: "15", dur: "5", text: "All of it." },
];
// @ts-ignore
const result = transcriptService.extractHook(subtitles);
expect(result).toBe("Short video. All of it.");
});
it("should return an empty string for an empty transcript", () => {
// @ts-ignore
const result = transcriptService.extractHook([]);
expect(result).toBe("");
});
});
describe("extractOutro", () => {
it("should return text from the last 30 seconds for a long video", () => {
const subtitles = [
{ start: "10", dur: "5", text: "Part 1." },
{ start: "50", dur: "5", text: "Part 2." },
{ start: "70", dur: "5", text: "Part 3." },
];
// @ts-ignore
const result = transcriptService.extractOutro(subtitles);
expect(result).toBe("Part 2. Part 3.");
});
it("should return the entire text for a video shorter than 30 seconds", () => {
const subtitles = [
{ start: "5", dur: "5", text: "Short video." },
{ start: "15", dur: "5", text: "All of it." },
];
// @ts-ignore
const result = transcriptService.extractOutro(subtitles);
expect(result).toBe("Short video. All of it.");
});
it("should return an empty string for an empty transcript", () => {
// @ts-ignore
const result = transcriptService.extractOutro([]);
expect(result).toBe("");
});
});
});
});
