t-youtube/backend/tests/test_summarizer.py

import pytest
import os
import httpx
import aiosqlite
import summarizer
from unittest.mock import patch, MagicMock, AsyncMock

class MockTranscript:
    def fetch(self):
        return [
            {"text": "Welcome to this video tutorial.", "start": 0.0, "duration": 3.0},
            {"text": "Today we are learning about Svelte 5 and runes.", "start": 3.0, "duration": 4.0}
        ]

class MockTranscriptList:
    def __init__(self, transcript):
        self.transcript = transcript

    def find_manually_created_transcript(self, languages):
        return self.transcript

    def find_generated_transcript(self, languages):
        return self.transcript

    def __iter__(self):
        return iter([self.transcript])

@pytest.mark.asyncio
async def test_download_transcript_success():
    mock_trans = MockTranscript()
    mock_list = MockTranscriptList(mock_trans)

    with patch("youtube_transcript_api.YouTubeTranscriptApi.list_transcripts", return_value=mock_list):
        text = summarizer.download_transcript("test_vid")
        assert text == "Welcome to this video tutorial. Today we are learning about Svelte 5 and runes."

@pytest.mark.asyncio
async def test_summarize_video_success(test_db):
    # Insert a pending video in db first
    await test_db.execute("""
        INSERT INTO videos (video_id, title, url, status)
        VALUES ('summarize_vid', 'Video to Summarize', 'https://www.youtube.com/watch?v=summarize_vid', 'pending')
    """)
    await test_db.commit()

    mock_trans = MockTranscript()
    mock_list = MockTranscriptList(mock_trans)

    # Mock Claude HTTP response
    mock_response = MagicMock(spec=httpx.Response)
    mock_response.status_code = 200
    mock_response.json.return_value = {
        "content": [
            {
                "text": "**Mock Core Hook**\n- Takeaway 1\n- Takeaway 2\nVerdict line."
            }
        ]
    }

    # Patch both transcript api and httpx AsyncClient post call
    with patch("youtube_transcript_api.YouTubeTranscriptApi.list_transcripts", return_value=mock_list), \
         patch("httpx.AsyncClient.post", new_callable=AsyncMock, return_value=mock_response) as mock_post:

        summary = await summarizer.summarize_video("summarize_vid")

        # Verify API request details
        mock_post.assert_called_once()
        url = mock_post.call_args[0][0]
        assert "bytecatcode.org" in url

        headers = mock_post.call_args[1]["headers"]
        assert "x-api-key" in headers
        assert headers["User-Agent"] is not None

        payload = mock_post.call_args[1]["json"]
        assert payload["model"] == "claude-haiku-4-5-20251001"
        assert len(payload["messages"]) == 1

        assert summary == "**Mock Core Hook**\n- Takeaway 1\n- Takeaway 2\nVerdict line."

    # Query db to verify transcript & summary were saved
    cursor = await test_db.execute("SELECT * FROM videos WHERE video_id = 'summarize_vid'")
    video = await cursor.fetchone()
    assert video is not None
    assert video["transcript"] == "Welcome to this video tutorial. Today we are learning about Svelte 5 and runes."
    assert video["summary"] == "**Mock Core Hook**\n- Takeaway 1\n- Takeaway 2\nVerdict line."

@pytest.mark.asyncio
async def test_summarize_all_pending(test_db):
    # Insert multiple videos, one pending and one already summarized
    await test_db.execute("""
        INSERT INTO videos (video_id, title, url, summary, status)
        VALUES
        ('pending_vid', 'Pending Video', 'https://youtube.com/watch?v=pending_vid', '', 'pending'),
        ('done_vid', 'Done Video', 'https://youtube.com/watch?v=done_vid', 'Existing summary', 'pending')
    """)
    await test_db.commit()

    mock_trans = MockTranscript()
    mock_list = MockTranscriptList(mock_trans)

    mock_response = MagicMock(spec=httpx.Response)
    mock_response.status_code = 200
    mock_response.json.return_value = {
        "content": [{"text": "Fresh summary"}]
    }

    with patch("youtube_transcript_api.YouTubeTranscriptApi.list_transcripts", return_value=mock_list), \
         patch("httpx.AsyncClient.post", new_callable=AsyncMock, return_value=mock_response) as mock_post:

        await summarizer.summarize_all_pending()

        # Should only call API once for 'pending_vid'
        mock_post.assert_called_once()
        payload = mock_post.call_args[1]["json"]
        assert "Welcome to this video tutorial." in payload["messages"][0]["content"]

    # Verify db states
    cursor = await test_db.execute("SELECT video_id, summary FROM videos ORDER BY video_id")
    videos = await cursor.fetchall()
    assert videos[0]["video_id"] == "done_vid"
    assert videos[0]["summary"] == "Existing summary" # Untouched

    assert videos[1]["video_id"] == "pending_vid"
    assert videos[1]["summary"] == "Fresh summary" # Updated