allow to set errors for rows scan

* 9a36c2e more examples and tests for rows
* 908877e cannot mock rows.Columns error so far

rows_test.go

@@ -0,0 +1,209 @@
+package sqlmock
+
+import (
+	"database/sql"
+	"fmt"
+	"testing"
+)
+
+func ExampleRows() {
+	db, mock, err := New()
+	if err != nil {
+		fmt.Println("failed to open sqlmock database:", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id", "title"}).
+		AddRow(1, "one").
+		AddRow(2, "two")
+
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	rs, _ := db.Query("SELECT")
+	defer rs.Close()
+
+	for rs.Next() {
+		var id int
+		var title string
+		rs.Scan(&id, &title)
+		fmt.Println("scanned id:", id, "and title:", title)
+	}
+
+	if rs.Err() != nil {
+		fmt.Println("got rows error:", rs.Err())
+	}
+	// Output: scanned id: 1 and title: one
+	// scanned id: 2 and title: two
+}
+
+func ExampleRows_rowError() {
+	db, mock, err := New()
+	if err != nil {
+		fmt.Println("failed to open sqlmock database:", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id", "title"}).
+		AddRow(0, "one").
+		AddRow(1, "two").
+		RowError(1, fmt.Errorf("row error"))
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	rs, _ := db.Query("SELECT")
+	defer rs.Close()
+
+	for rs.Next() {
+		var id int
+		var title string
+		rs.Scan(&id, &title)
+		fmt.Println("scanned id:", id, "and title:", title)
+	}
+
+	if rs.Err() != nil {
+		fmt.Println("got rows error:", rs.Err())
+	}
+	// Output: scanned id: 0 and title: one
+	// got rows error: row error
+}
+
+func ExampleRows_closeError() {
+	db, mock, err := New()
+	if err != nil {
+		fmt.Println("failed to open sqlmock database:", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id", "title"}).CloseError(fmt.Errorf("close error"))
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	rs, _ := db.Query("SELECT")
+
+	// Note: that close will return error only before rows EOF
+	// that is a default sql package behavior. If you run rs.Next()
+	// it will handle the error internally and return nil bellow
+	if err := rs.Close(); err != nil {
+		fmt.Println("got error:", err)
+	}
+
+	// Output: got error: close error
+}
+
+func TestAllowsToSetRowsErrors(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id", "title"}).
+		AddRow(0, "one").
+		AddRow(1, "two").
+		RowError(1, fmt.Errorf("error"))
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	rs, err := db.Query("SELECT")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+	defer rs.Close()
+
+	if !rs.Next() {
+		t.Fatal("expected the first row to be available")
+	}
+	if rs.Err() != nil {
+		t.Fatalf("unexpected error: %s", rs.Err())
+	}
+
+	if rs.Next() {
+		t.Fatal("was not expecting the second row, since there should be an error")
+	}
+	if rs.Err() == nil {
+		t.Fatal("expected an error, but got none")
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestRowsCloseError(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id"}).CloseError(fmt.Errorf("close error"))
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	rs, err := db.Query("SELECT")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	if err := rs.Close(); err == nil {
+		t.Fatal("expected a close error")
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestQuerySingleRow(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	rows := NewRows([]string{"id"}).
+		AddRow(1).
+		AddRow(2)
+	mock.ExpectQuery("SELECT").WillReturnRows(rows)
+
+	var id int
+	if err := db.QueryRow("SELECT").Scan(&id); err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	mock.ExpectQuery("SELECT").WillReturnRows(NewRows([]string{"id"}))
+	if err := db.QueryRow("SELECT").Scan(&id); err != sql.ErrNoRows {
+		t.Fatal("expected sql no rows error")
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// @TODO: the only way to mock columns error would be
+// to return nil instead of rows, but rows.Close will
+// panic due to a bug in go sql package
+func TODO_TestRowsColumnsError(t *testing.T) {
+	t.Parallel()
+	db, mock, err := New()
+	if err != nil {
+		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
+	}
+	defer db.Close()
+
+	mock.ExpectQuery("SELECT").WillReturnRows(nil)
+
+	rs, err := db.Query("SELECT")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	_, err = rs.Columns()
+	if err == nil {
+		t.Fatal("expected an error for columns")
+	}
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}