ninth version

internal/marketdata/loader.go

@@ -30,7 +30,6 @@ func (l *Loader) SetClock(clock timeutil.Clock) {
 func (l Loader) BackfillDaily(ctx context.Context, instruments []domain.Instrument, from, to time.Time) error {
 	eligible := 0
 	succeeded := 0
-	var firstErr error
 	for _, instrument := range instruments {
 		if !instrument.Enabled || instrument.Quarantine {
 			continue
@@ -38,18 +37,15 @@ func (l Loader) BackfillDaily(ctx context.Context, instruments []domain.Instrume
 		eligible++
 		candles, err := l.gateway.GetCandles(ctx, instrument.InstrumentUID, "day", from, to)
 		if err != nil {
-			if firstErr == nil {
-				firstErr = fmt.Errorf("load candles %s: %w", instrument.Ticker, err)
-			}
-			continue
+			return fmt.Errorf("load daily candles %s: %w", instrument.Ticker, err)
 		}
 		if err := l.repo.UpsertDailyCandles(ctx, candles); err != nil {
 			return fmt.Errorf("persist candles %s: %w", instrument.Ticker, err)
 		}
 		succeeded++
 	}
-	if eligible > 0 && succeeded == 0 && firstErr != nil {
-		return fmt.Errorf("all daily candle loads failed: %w", firstErr)
+	if eligible > 0 && succeeded == 0 {
+		return fmt.Errorf("no daily candles loaded for eligible instruments")
 	}
 	return nil
 }
@@ -57,7 +53,6 @@ func (l Loader) BackfillDaily(ctx context.Context, instruments []domain.Instrume
 func (l Loader) BackfillMinute(ctx context.Context, instruments []domain.Instrument, from, to time.Time) error {
 	eligible := 0
 	succeeded := 0
-	var firstErr error
 	for _, instrument := range instruments {
 		if !instrument.Enabled || instrument.Quarantine {
 			continue
@@ -65,18 +60,15 @@ func (l Loader) BackfillMinute(ctx context.Context, instruments []domain.Instrum
 		eligible++
 		candles, err := l.gateway.GetCandles(ctx, instrument.InstrumentUID, "minute", from, to)
 		if err != nil {
-			if firstErr == nil {
-				firstErr = fmt.Errorf("load minute candles %s: %w", instrument.Ticker, err)
-			}
-			continue
+			return fmt.Errorf("load minute candles %s: %w", instrument.Ticker, err)
 		}
 		if err := l.repo.UpsertMinuteCandles(ctx, candles); err != nil {
 			return fmt.Errorf("persist minute candles %s: %w", instrument.Ticker, err)
 		}
 		succeeded++
 	}
-	if eligible > 0 && succeeded == 0 && firstErr != nil {
-		return fmt.Errorf("all minute candle loads failed: %w", firstErr)
+	if eligible > 0 && succeeded == 0 {
+		return fmt.Errorf("no minute candles loaded for eligible instruments")
 	}
 	return nil
 }

internal/marketdata/loader_test.go

@@ -2,6 +2,7 @@ package marketdata
 
 import (
 	"context"
+	"errors"
 	"strings"
 	"testing"
 	"time"
@@ -9,6 +10,7 @@ import (
 	"github.com/shopspring/decimal"
 
 	"overnight-trading-bot/internal/domain"
+	"overnight-trading-bot/internal/testutil"
 	"overnight-trading-bot/internal/tinvest"
 )
 
@@ -41,3 +43,45 @@ func TestLatestQuoteUsesExchangeTimestampForFreshness(t *testing.T) {
 		t.Fatalf("LatestQuote err=%v, want stale exchange timestamp rejection", err)
 	}
 }
+
+func TestBackfillDailyFailsOnAnyEligibleInstrumentError(t *testing.T) {
+	ctx := context.Background()
+	gateway := tinvest.NewFakeGateway()
+	repo := testutil.NewMemoryRepository()
+	gateway.Candles["ok"] = []domain.Candle{{
+		InstrumentUID: "ok",
+		TradeDate:     time.Date(2026, 6, 8, 0, 0, 0, 0, time.UTC),
+		Close:         decimal.NewFromInt(100),
+	}}
+	gateway.CandleErrors["bad"] = errors.New("candles unavailable")
+	loader := NewLoader(repo, gateway)
+
+	err := loader.BackfillDaily(ctx, []domain.Instrument{
+		{InstrumentUID: "ok", Ticker: "OK", Enabled: true},
+		{InstrumentUID: "bad", Ticker: "BAD", Enabled: true},
+	}, time.Date(2026, 6, 1, 0, 0, 0, 0, time.UTC), time.Date(2026, 6, 8, 0, 0, 0, 0, time.UTC))
+	if err == nil {
+		t.Fatal("expected per-instrument backfill error")
+	}
+}
+
+func TestBackfillMinuteFailsOnAnyEligibleInstrumentError(t *testing.T) {
+	ctx := context.Background()
+	gateway := tinvest.NewFakeGateway()
+	repo := testutil.NewMemoryRepository()
+	gateway.Candles["ok"] = []domain.Candle{{
+		InstrumentUID: "ok",
+		TradeDate:     time.Date(2026, 6, 8, 18, 10, 0, 0, time.UTC),
+		Close:         decimal.NewFromInt(100),
+	}}
+	gateway.CandleErrors["bad"] = errors.New("minute candles unavailable")
+	loader := NewLoader(repo, gateway)
+
+	err := loader.BackfillMinute(ctx, []domain.Instrument{
+		{InstrumentUID: "ok", Ticker: "OK", Enabled: true},
+		{InstrumentUID: "bad", Ticker: "BAD", Enabled: true},
+	}, time.Date(2026, 6, 8, 18, 0, 0, 0, time.UTC), time.Date(2026, 6, 8, 19, 0, 0, 0, time.UTC))
+	if err == nil {
+		t.Fatal("expected per-instrument minute backfill error")
+	}
+}