BREAKING CHANGE: Complete redesign of backtest execution
- Add BacktestJob system with progress stages (validating, fetching_prices, calculating)
- Run backtests in background threads, UI polls for status
- Show progress label with current stage during execution
- Remove synchronous Databento API calls from page load
- Use static default entry spot for initial render (defers API call)
- Make refresh_workspace_seeded_units async with run.io_bound
This fixes:
- 'Connection lost' WebSocket timeout errors
- Slow page load (30s initial load)
- Backtest never completing
The job system provides:
- Non-blocking execution
- Progress tracking with stages
- Error handling with user-friendly messages
- Result caching for retrieval after completion
- Use run.io_bound() from NiceGUI to run Databento API calls in background thread
- Add loading state to Run Backtest button
- Show notification when backtest starts and completes
- Remove loading state on completion/error
This prevents 'Connection lost' errors when the backtest takes longer than the WebSocket timeout.
- on_form_change: Only update cost estimate, skip expensive derive_entry_spot
- Only call derive_entry_spot on date changes (start/end inputs)
- Other inputs (template, units, loan, LTV) just mark results stale
- This reduces lag from constant API polling
- Set default dates to 2024-07-01 to 2024-12-31 (valid for XNAS.BASIC)
- Catch all exceptions during entry spot derivation, not just ValueError
- Don't auto-run backtest on page load - let user configure first
- Use recent GLD price (~30) as fallback
- Add DATABENTO_DATASET_MIN_DATES for XNAS.BASIC (2024-07-01) and GLBX.MDP3 (2010-01-01)
- Validate start date against dataset minimum before running backtest
- Parse Databento API errors and show user-friendly messages
- Update date range hint to show dataset-specific availability
- Catch BentoClientError and show appropriate warning tone
- Pass data_source to derive_entry_spot in backtests.py
- Remove default 'synthetic' value for data_source in derive_entry_spot and validate_preview_inputs
- Update all tests to explicitly pass data_source parameter
- Improve error message with helpful suggestion for Databento/Yahoo Finance
- Change WindowPolicy from EXACT to BOUNDED for backtest fixture
- Pass data_source to run_read_only_scenario so real data can be used
- Fix injected provider identity preservation in BacktestPageService
- Add type: ignore for BacktestHistoricalProvider protocol assignment
- Revert TypedDict change to avoid cascading type issues in pages/
- Update tests to reflect new BOUNDED policy behavior
1. Fix Friday logic edge case comment
- Clarified get_default_backtest_dates() docstring
- Removed confusing 'at least a week old' comment
- Explicitly documented Friday behavior
2. Reorder validation checks in validate_date_range_for_symbol()
- Now checks start > end first (most fundamental)
- Then checks end > today (future dates)
- Finally checks symbol-specific bounds
- Users get most actionable error first
3. Add server-side numeric bounds validation
- New validate_numeric_inputs() function
- Validates units > 0, loan >= 0, 0 < LTV < 1
- Called in run_backtest() before service call
4. Add boundary tests
- Test start_date exactly at SYMBOL_MIN_DATES boundary
- Test same-day date range (start == end)
- Test end_date exactly today
- Test end_date tomorrow (future)
- Test validation order returns most actionable error
- Test near-zero and large values for units calculation
- Test LTV at boundaries (0, 1, 0.01, 0.99)
5. Add tests for validate_numeric_inputs
- Valid inputs, zero/negative values
- LTV boundary conditions
- Changed default date range from 5 days (Jan 2024) to 2 years (2022-2023)
- Added SYMBOL_MIN_DATES constant documenting data availability per symbol
- GLD minimum date: 2004-11-18 (ETF launch)
- GC futures minimum date: 1974-01-01
- XAU index minimum date: 1970-01-01
- Added UI hint showing GLD data availability from ETF launch
- Users can now run backtests across the full historical range
