improve test coverage, error reporting for Select()

2 files changed, 17 insertions, 3 deletions

diff --git a/internal/assert/assert.go b/internal/assert/assert.go
index 26f91ff..6e641ca 100644
--- a/internal/assert/assert.go
+++ b/internal/assert/assert.go
@@ -4,6 +4,8 @@
 package assert
 
 import (
+	"cmp"
+	"errors"
 	"reflect"
 	"testing"
 )
@@ -26,6 +28,12 @@ func DeepEqual[V any](t testing.TB, actual, expected V) {
 	}
 }
 
+// ErrEqual is a test assertion.
+func ErrEqual(t testing.TB, actual error, expected string) {
+	t.Helper()
+	Equal(t, cmp.Or(actual, errors.New("<success>")).Error(), expected)
+}
+
 // SliceEqual is a test assertion.
 func SliceEqual[V comparable](t testing.TB, actual []V, expected ...V) {
 	t.Helper()
diff --git a/internal/mock/mock.go b/internal/mock/mock.go
index d3358c4..ecbb03e 100644
--- a/internal/mock/mock.go
+++ b/internal/mock/mock.go
@@ -245,8 +245,9 @@ func (r result) RowsAffected() (int64, error) {
 // Rows is a mock response for a Query() or QueryRow() call.
 // It is constructed by [ResponseSet.ExpectQuery].
 type Rows struct {
-	columns []string
-	results [][]any
+	columns    []string
+	results    [][]any
+	closeError error
 }
 
 // AndReturnColumns configures the set of column names that will be returend by this query.
@@ -272,6 +273,11 @@ func (r *Rows) WithRow(values ...any) *Rows {
 	return r
 }
 
+// AndCloseFailsWith sets up Close() for this Rows to fail with the provided error message.
+func (r *Rows) AndCloseFailsWith(err error) {
+	r.closeError = err
+}
+
 type rows struct {
 	r      Rows
 	closed bool
@@ -285,7 +291,7 @@ func (r *rows) Columns() []string {
 // Close implements the [driver.Rows] interface.
 func (r *rows) Close() error {
 	r.closed = true
-	return nil
+	return r.r.closeError
 }
 
 // Next implements the [driver.Rows] interface.