fix(sqlbuilder): return build error from selector.statement

internal/sqlbuilder/select.go

@@ -424,9 +424,12 @@ func (sel *selector) As(alias string) db.Selector {
 	})
 }
 
-func (sel *selector) statement() *exql.Statement {
-	sq, _ := sel.build()
-	return sq.statement()
+func (sel *selector) statement() (*exql.Statement, error) {
+	sq, err := sel.build()
+	if err != nil {
+		return nil, err
+	}
+	return sq.statement(), nil
 }
 
 func (sel *selector) QueryRow() (*sql.Row, error) {
@@ -502,7 +505,11 @@ func (sel *selector) build() (*selectorQuery, error) {
 }
 
 func (sel *selector) Compile() (string, error) {
-	return sel.statement().Compile(sel.template())
+	s, err := sel.statement()
+	if err != nil {
+		return "", err
+	}
+	return s.Compile(sel.template())
 }
 
 func (sel *selector) Prev() immutable.Immutable {

internal/sqlbuilder/select_nil_test.go

@@ -0,0 +1,43 @@
+package sqlbuilder
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAsWithoutFromDoesNotNilPanic(t *testing.T) {
+	b := &sqlBuilder{t: newTemplateWithUtils(&testTemplate)}
+
+	// Valid path still works.
+	assert.Contains(t, b.SelectFrom("artist").As("a").String(), "artist")
+
+	// As without From used to nil-deref inside statement(); now surface a real error.
+	defer func() {
+		r := recover()
+		if r == nil {
+			t.Fatal("expected panic with error message, got none")
+		}
+		msg, ok := r.(string)
+		if !ok {
+			t.Fatalf("expected string panic, got %T %v", r, r)
+		}
+		if strings.Contains(msg, "nil pointer") || strings.Contains(msg, "invalid memory") {
+			t.Fatalf("still nil-pointer style panic: %s", msg)
+		}
+		if !strings.Contains(msg, "As()") {
+			t.Fatalf("unexpected error message: %s", msg)
+		}
+	}()
+	_ = b.Select("id").As("alias").String()
+}
+
+func TestSelectorStatementReturnsBuildError(t *testing.T) {
+	b := &sqlBuilder{t: newTemplateWithUtils(&testTemplate)}
+	sel := b.Select("id").As("alias").(*selector)
+	st, err := sel.statement()
+	assert.Nil(t, st)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "As()")
+}