fix(go): backfill realtime plate from binding

go/vehicle-gateway/internal/realtime/snapshot_writer_test.go

@@ -3,6 +3,7 @@ package realtime
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"strings"
 	"testing"
 
@@ -126,6 +127,109 @@ func TestSnapshotWriterUpsertsRealtimeLocationWhenCoordinatesExist(t *testing.T)
 	}
 }
 
+func TestSnapshotWriterBackfillsPlateFromBindingByVIN(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	resolver := &recordingPlateResolver{plate: "沪A12345"}
+	writer := NewSnapshotWriterWithPlateResolver(exec, resolver)
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolGB32960,
+		MessageID:    "0x02",
+		VIN:          "VIN001",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed:       map[string]any{"data_units": []any{}},
+		Fields: map[string]any{
+			envelope.FieldLatitude:  30.590151,
+			envelope.FieldLongitude: 121.069881,
+		},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+
+	if resolver.vin != "VIN001" {
+		t.Fatalf("resolver vin = %q", resolver.vin)
+	}
+	if len(exec.calls) != 2 {
+		t.Fatalf("exec calls = %d, want 2", len(exec.calls))
+	}
+	if got, want := exec.calls[0].args[5], "沪A12345"; got != want {
+		t.Fatalf("snapshot plate arg = %#v, want %q", got, want)
+	}
+	if got, want := exec.calls[1].args[5], "沪A12345"; got != want {
+		t.Fatalf("location plate arg = %#v, want %q", got, want)
+	}
+}
+
+func TestSnapshotWriterKeepsEventPlateWhenPresent(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	resolver := &recordingPlateResolver{plate: "沪B99999"}
+	writer := NewSnapshotWriterWithPlateResolver(exec, resolver)
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolJT808,
+		MessageID:    "0x0200",
+		VIN:          "VIN001",
+		Plate:        "沪A12345",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Fields: map[string]any{
+			envelope.FieldLatitude:  30.590151,
+			envelope.FieldLongitude: 121.069881,
+		},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+
+	if resolver.vin != "" {
+		t.Fatalf("resolver should not be called, got vin=%q", resolver.vin)
+	}
+	if got, want := exec.calls[0].args[5], "沪A12345"; got != want {
+		t.Fatalf("snapshot plate arg = %#v, want %q", got, want)
+	}
+}
+
+func TestSnapshotWriterIgnoresMissingBindingPlate(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	writer := NewSnapshotWriterWithPlateResolver(exec, &recordingPlateResolver{err: sql.ErrNoRows})
+
+	if err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolGB32960,
+		MessageID:    "0x02",
+		VIN:          "VIN001",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed:       map[string]any{"data_units": []any{}},
+		Fields:       map[string]any{envelope.FieldSOCPercent: 90},
+	}); err != nil {
+		t.Fatalf("Update() error = %v", err)
+	}
+	if got := exec.calls[0].args[5]; got != "" {
+		t.Fatalf("snapshot plate arg = %#v, want empty", got)
+	}
+}
+
+func TestSnapshotWriterReturnsUnexpectedPlateLookupError(t *testing.T) {
+	exec := &recordingSnapshotExec{}
+	writer := NewSnapshotWriterWithPlateResolver(exec, &recordingPlateResolver{err: errors.New("db down")})
+
+	err := writer.Update(context.Background(), envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolGB32960,
+		MessageID:    "0x02",
+		VIN:          "VIN001",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918601000,
+		Parsed:       map[string]any{"data_units": []any{}},
+		Fields:       map[string]any{envelope.FieldSOCPercent: 90},
+	})
+	if err == nil || !strings.Contains(err.Error(), "db down") {
+		t.Fatalf("Update() error = %v, want db down", err)
+	}
+	if len(exec.calls) != 0 {
+		t.Fatalf("exec calls = %d, want 0", len(exec.calls))
+	}
+}
+
 func TestSnapshotWriterSkipsUnknownVehicleKey(t *testing.T) {
 	exec := &recordingSnapshotExec{}
 	writer := NewSnapshotWriter(exec)
@@ -176,3 +280,14 @@ func (e *recordingSnapshotExec) ExecContext(_ context.Context, query string, arg
 	e.calls = append(e.calls, snapshotExecCall{query: query, args: args})
 	return nil, nil
 }
+
+type recordingPlateResolver struct {
+	vin   string
+	plate string
+	err   error
+}
+
+func (r *recordingPlateResolver) PlateByVIN(_ context.Context, vin string) (string, error) {
+	r.vin = vin
+	return r.plate, r.err
+}