From 6d3df1469c831c26fc09f39c3417b0254911e2c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=88=E6=9D=A8=E6=96=87?= <wenermail@gmail.com>
Date: Wed, 5 May 2021 22:09:55 +0800
Subject: [PATCH] dialect/sql: include nested builder errors on join (#1533)

* sql.Builder Join include Querier's error

* sql.Builder Join ignore nil error

Co-authored-by: Ariel Mashraki <7413593+a8m@users.noreply.github.com>

Co-authored-by: Ariel Mashraki <7413593+a8m@users.noreply.github.com>
---
 dialect/sql/builder.go      | 16 +++++++++++++++-
 dialect/sql/builder_test.go |  5 +++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/dialect/sql/builder.go b/dialect/sql/builder.go
index ef2ea5a80..61a71d508 100644
--- a/dialect/sql/builder.go
+++ b/dialect/sql/builder.go
@@ -29,6 +29,11 @@ type Querier interface {
 	Query() (string, []interface{})
 }
 
+// querierErr allowed propagate Querier's inner error
+type querierErr interface {
+	Err() error
+}
+
 // ColumnBuilder is a builder for column definition in table creation.
 type ColumnBuilder struct {
 	Builder
@@ -2091,6 +2096,7 @@ func (s *Selector) Query() (string, []interface{}) {
 		b.WriteString(strconv.Itoa(*s.offset))
 	}
 	s.total = b.total
+	s.AddError(b.Err())
 	return b.String(), b.args
 }
 
@@ -2326,7 +2332,10 @@ func (b *Builder) Reset() *Builder {
 
 // AddError appends an error to the builder errors.
 func (b *Builder) AddError(err error) *Builder {
-	b.errs = append(b.errs, err)
+	// allowed nil error make build process easier
+	if err != nil {
+		b.errs = append(b.errs, err)
+	}
 	return b
 }
 
@@ -2488,6 +2497,11 @@ func (b *Builder) join(qs []Querier, sep string) *Builder {
 		b.WriteString(query)
 		b.args = append(b.args, args...)
 		b.total += len(args)
+		if qe, ok := q.(querierErr); ok {
+			if err := qe.Err(); err != nil {
+				b.AddError(err)
+			}
+		}
 	}
 	return b
 }
diff --git a/dialect/sql/builder_test.go b/dialect/sql/builder_test.go
index 610f4020c..99f66ad6f 100644
--- a/dialect/sql/builder_test.go
+++ b/dialect/sql/builder_test.go
@@ -1490,6 +1490,11 @@ func TestBuilder_Err(t *testing.T) {
 	require.EqualError(t, b.Err(), "invalid")
 	b.AddError(fmt.Errorf("unexpected"))
 	require.EqualError(t, b.Err(), "invalid; unexpected")
+	b.Where(P(func(builder *Builder) {
+		builder.AddError(fmt.Errorf("inner"))
+	}))
+	_, _ = b.Query()
+	require.EqualError(t, b.Err(), "invalid; unexpected; inner")
 }
 
 func TestSelector_OrderByExpr(t *testing.T) {