QA: State Streaming — Google ADK

Prerequisites

• Demo is deployed and accessible at /demos/shared-state-streaming on the dashboard host
• Agent backend is healthy (/api/health); GOOGLE_API_KEY is set (or GOOGLE_GEMINI_BASE_URL points at the aimock proxy)
• Per-token granularity requires google-adk >= 1.24.0 on Vertex AI. Gemini Studio falls back to chunk-level deltas (still streams; just coarser).

Test Steps

1. Basic Functionality

• Navigate to /demos/shared-state-streaming; verify the page renders within 3s with the "Document" panel filling the viewport and the CopilotSidebar open by default on the right
• Verify the document panel shows the heading "Document" and the empty-state hint "Ask the agent to write something — its output will stream here token by token."
• Verify the char-count badge reads 0 chars and no "Live" badge is visible on initial load
• Verify the chat input placeholder reads "Ask me to write something..."
• Send "Hello" and verify the agent responds within 10s

2. Feature-Specific Checks

Suggestions

• Verify all 3 suggestion pills are visible with verbatim titles:
  • "Write a short poem"
  • "Draft an email"
  • "Explain quantum computing"

Per-Token State Streaming (Predict-State Mapping)

• Click "Write a short poem"
• Within 5s verify the "Live" badge appears next to the "Document" heading (data-testid="document-live-badge")
• Verify the document-content node mounts with text growing over time (each render contains MORE text than the prior one for at least 2 ticks); the char-count display ticks upward in lockstep
• Verify the inline blinking cursor element renders alongside the streaming text while the agent is running
• Verify the streamed output forms a coherent short poem about autumn leaves (a few stanzas / lines, not a single token)
• Once the agent finishes, verify the "Live" badge and the cursor disappear and the final document text remains rendered

Streaming Path Selector

• Confirm via the /api/health JSON or Railway logs whether the run used Vertex AI per-token deltas or Gemini Studio chunk-level deltas
• Either path is acceptable for this demo — the UI must still display token-by-token or chunk-by-chunk growth without freezing on the final value

Second Pill Re-Streams Cleanly

• In the same session, click "Draft an email"
• Verify the document area replaces the prior content (no concatenation) and the new content streams in
• Verify the "Live" badge re-mounts during the new run

3. Error Handling

• Send an empty message; verify it is a no-op
• Verify no uncaught console errors during any streaming cycle above

Expected Results

• Chat loads within 3 seconds; initial document streaming starts within 5 seconds of the triggering prompt
• The document text visibly grows on the page (not a single end-of-run update)
• The "Live" badge and blinking cursor reflect isRunning accurately
• No console errors, no stuck-state, no orphaned half-streamed output