From c25f85be4bd87a104abff8dd3851cb75b8dd1855 Mon Sep 17 00:00:00 2001
From: Daniel Gaiottino <daniel.gaiottino@gmail.com>
Date: Mon, 23 Aug 2021 12:32:45 +0200
Subject: [PATCH] Support sqlcommenter comments
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https://google.github.io/sqlcommenter/ makes it possible to add tracing comments that can be interpreted by e.g. GCPs query analyser.

https://github.com/volatiletech/sqlboiler/pull/872 added support for comments but they are prepended on a separate line and sqlcommenter requires the form `/* … */` to be added on the same line as the query which is why I’ve added this PR and the `qm.AppendComment` function.

For example:
```
q := shop.Customers(
  qm.AppendComment("shop.getAllCustomers"),
  qm.Select("id", "name"),
  qm.From("customers"),
)
```
will be:
```
SELECT id, name FROM customers; /* shop.getAllCustomers /*
```
---
 queries/query.go               | 38 ++++++++++++++++++++--------------
 queries/query_builders.go      | 17 +++++++++++++++
 queries/query_builders_test.go | 30 +++++++++++++++++++++++++++
 queries/query_test.go          | 11 ++++++++++
 4 files changed, 80 insertions(+), 16 deletions(-)

diff --git a/queries/query.go b/queries/query.go
index 5e99d4ebd..dc811dc39 100644
--- a/queries/query.go
+++ b/queries/query.go
@@ -30,22 +30,23 @@ type Query struct {
 	load     []string
 	loadMods map[string]Applicator
 
-	delete     bool
-	update     map[string]interface{}
-	withs      []argClause
-	selectCols []string
-	count      bool
-	from       []string
-	joins      []join
-	where      []where
-	groupBy    []string
-	orderBy    []argClause
-	having     []argClause
-	limit      *int
-	offset     int
-	forlock    string
-	distinct   string
-	comment    string
+	delete        bool
+	update        map[string]interface{}
+	withs         []argClause
+	selectCols    []string
+	count         bool
+	from          []string
+	joins         []join
+	where         []where
+	groupBy       []string
+	orderBy       []argClause
+	having        []argClause
+	limit         *int
+	offset        int
+	forlock       string
+	distinct      string
+	comment       string
+	appendComment string
 
 	// This field is a hack to allow a query to strip out the reference
 	// to deleted at is null.
@@ -281,6 +282,11 @@ func SetComment(q *Query, comment string) {
 	q.comment = comment
 }
 
+// SetAppendComment on the query.
+func SetAppendComment(q *Query, appendComment string) {
+	q.appendComment = appendComment
+}
+
 // SetUpdate on the query.
 func SetUpdate(q *Query, cols map[string]interface{}) {
 	q.update = cols
diff --git a/queries/query_builders.go b/queries/query_builders.go
index 7f5cc1a72..de6e7693d 100644
--- a/queries/query_builders.go
+++ b/queries/query_builders.go
@@ -134,6 +134,9 @@ func buildSelectQuery(q *Query) (*bytes.Buffer, []interface{}) {
 	writeModifiers(q, buf, &args)
 
 	buf.WriteByte(';')
+
+	writeAppendComment(q, buf)
+
 	return buf, args
 }
 
@@ -157,6 +160,8 @@ func buildDeleteQuery(q *Query) (*bytes.Buffer, []interface{}) {
 
 	buf.WriteByte(';')
 
+	writeAppendComment(q, buf)
+
 	return buf, args
 }
 
@@ -201,6 +206,8 @@ func buildUpdateQuery(q *Query) (*bytes.Buffer, []interface{}) {
 
 	buf.WriteByte(';')
 
+	writeAppendComment(q, buf)
+
 	return buf, args
 }
 
@@ -604,6 +611,16 @@ func writeComment(q *Query, buf *bytes.Buffer) {
 	}
 }
 
+func writeAppendComment(q *Query, buf *bytes.Buffer) {
+	if len(q.appendComment) == 0 {
+		return
+	}
+
+	buf.WriteString(" /* ")
+	buf.WriteString(q.appendComment)
+	buf.WriteString(" */ ")
+}
+
 func writeCTEs(q *Query, buf *bytes.Buffer, args *[]interface{}) {
 	if len(q.withs) == 0 {
 		return
diff --git a/queries/query_builders_test.go b/queries/query_builders_test.go
index 892d8dde0..f94dc2441 100644
--- a/queries/query_builders_test.go
+++ b/queries/query_builders_test.go
@@ -699,3 +699,33 @@ func TestWriteComment(t *testing.T) {
 		t.Errorf(`bad two lines comment, got: %s`, got)
 	}
 }
+
+func TestWriteAppendComment(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		appendComment   string
+		expectPredicate func(sql string) bool
+	}{
+		{"", func(sql string) bool {
+			return !strings.Contains(sql, "/*")
+		}},
+		{"comment", func(sql string) bool {
+			return strings.Contains(sql, "; /* comment */")
+		}},
+		{"first\nsecond", func(sql string) bool {
+			return strings.Contains(sql, "; /* first\nsecond */")
+		}},
+	}
+
+	for i, test := range tests {
+		q := &Query{
+			appendComment: test.appendComment,
+			dialect:       &drivers.Dialect{LQ: '"', RQ: '"', UseIndexPlaceholders: true, UseTopClause: false},
+		}
+		sql, _ := BuildQuery(q)
+		if !test.expectPredicate(sql) {
+			t.Errorf("%d) Unexpected built SQL query: %s", i, sql)
+		}
+	}
+}
diff --git a/queries/query_test.go b/queries/query_test.go
index f813ea61e..72557e1cc 100644
--- a/queries/query_test.go
+++ b/queries/query_test.go
@@ -654,6 +654,17 @@ func TestSetComment(t *testing.T) {
 	}
 }
 
+func TestSetAppendComment(t *testing.T) {
+	t.Parallel()
+
+	q := &Query{}
+	SetAppendComment(q, "my comment")
+
+	if q.appendComment != "my comment" {
+		t.Errorf("Got invalid comment: %s", q.appendComment)
+	}
+}
+
 func TestRemoveSoftDeleteWhere(t *testing.T) {
 	t.Parallel()