adding better error handling around connections

sqlite.go

@@ -3,6 +3,7 @@ package lite
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"os"
 
@@ -11,6 +12,10 @@ import (
 	_ "github.com/ncruces/go-sqlite3/embed"
 )
 
+var (
+	ErrNotConnected = errors.New("the connect method must be called before any queries can be executed")
+)
+
 type database struct {
 	file   string
 	path   string
@@ -22,7 +27,7 @@ type Database interface {
 	Close() error
 	Exec(ctx context.Context, query string, args ...any) (sql.Result, error)
 	Query(ctx context.Context, query string, args ...any) (*sqlx.Rows, error)
-	QueryRow(ctx context.Context, query string, args ...any) *sqlx.Row
+	QueryRow(ctx context.Context, query string, args ...any) (*sqlx.Row, error)
 	QueryIn(ctx context.Context, query string, args ...any) (*sqlx.Rows, error)
 }
 
@@ -65,21 +70,33 @@ func (d *database) Close() error {
 
 // runs any updates, inserts, or any other queries that do not return rows
 func (d *database) Exec(ctx context.Context, query string, args ...any) (sql.Result, error) {
+	if d.sqlite == nil {
+		return nil, ErrNotConnected
+	}
 	return d.sqlite.ExecContext(ctx, query, args...)
 }
 
 // runs basic data queries
 func (d *database) Query(ctx context.Context, query string, args ...any) (*sqlx.Rows, error) {
+	if d.sqlite == nil {
+		return nil, ErrNotConnected
+	}
 	return d.sqlite.QueryxContext(ctx, query, args...)
 }
 
 // retrieves a single row from database
-func (d *database) QueryRow(ctx context.Context, query string, args ...any) *sqlx.Row {
-	return d.sqlite.QueryRowxContext(ctx, query, args...)
+func (d *database) QueryRow(ctx context.Context, query string, args ...any) (*sqlx.Row, error) {
+	if d.sqlite == nil {
+		return nil, ErrNotConnected
+	}
+	return d.sqlite.QueryRowxContext(ctx, query, args...), nil
 }
 
 // runs queries that require parameters in an IN clause
 func (d *database) QueryIn(ctx context.Context, query string, args ...any) (*sqlx.Rows, error) {
+	if d.sqlite == nil {
+		return nil, ErrNotConnected
+	}
 	q, ar, err := sqlx.In(query, args...)
 	if err != nil {
 		return nil, err