gps-denied-desktop/docs/03_tests/25_real_time_streaming_pipeline_spec.md

System Integration Test: Real-Time Streaming Pipeline

Summary

Validate real-time streaming of results via SSE as images are processed (AC-8 requirement).

Components Under Test

• Image Input Pipeline
• Vision Layers (L1, L2, L3)
• Factor Graph Optimizer
• Result Manager
• SSE Event Streamer
• Flight Manager

Test Scenario

Per AC-8: "Results of image processing should appear immediately to user, so that user shouldn't wait for the whole route to complete."

Test that:

1. Images uploaded and queued
2. Processing starts immediately
3. Results streamed to client < 1s after processing
4. Refinements sent when trajectory updated
5. User can analyze early results before flight completes

Test Cases

Test Case 1: Immediate Result Delivery

• Upload 10 images
• Connect SSE client
• Measure time from image processed to event received
• Target: < 1 second latency (AC-8 "immediately")

Test Case 2: Progressive Results

• Upload 30 images
• Monitor SSE stream
• Verify first results available before image 30 processed
• Target: First result within 10 seconds of upload

Test Case 3: Refinement Notifications

• Process 20 images
• New GPS anchor added (image 20)
• Factor graph refines trajectory for images 1-19
• Verify "trajectory_refined" event sent
• Target: Refinement notification within 2 seconds

Test Case 4: Multiple Concurrent Clients

• 3 clients connect to same flight SSE stream
• All receive events simultaneously
• No delays between clients
• Target: All clients receive within 100ms of each other

Test Case 5: Late-Joining Client

• Flight already processing (10 images done)
• New client connects
• Receives catch-up of existing results plus live stream
• Target: Seamless experience

Test Case 6: Backpressure Handling

• Process images rapidly (50 images in 60 seconds)
• Verify SSE can handle high event rate
• No event loss or buffer overflow
• Target: All events delivered, no loss

Success Criteria

• Result latency < 1 second (AC-8)
• First results available immediately
• Refinements streamed when they occur
• Multiple clients supported
• No event loss under load

Maximum Expected Time

• Setup: < 5 seconds
• Process 30 images with streaming: < 150 seconds
• Total test: < 180 seconds

Pass/Fail Criteria

Passes If: AC-8 requirements met, latency < 1s, refinements streamed, no event loss Fails If: Latency > 2s, events lost, clients not notified of refinements