gen: Turn SQL comments into Go comments (sqlc-dev#136)

Remove comments from SQL and add them as Go comments

Author: kyleconroy

internal/dinosql/gen.go

@@ -143,6 +143,7 @@ func (v GoQueryValue) Scan() string {
 // A struct used to generate methods and fields on the Queries struct
 type GoQuery struct {
 	Cmd          string
+	Comments     []string
 	MethodName   string
 	FieldName    string
 	ConstantName string
@@ -646,6 +647,7 @@ func (r Result) GoQueries() []GoQuery {
 			MethodName:   query.Name,
 			SourceName:   query.Filename,
 			SQL:          code,
+			Comments:     query.Comments,
 		}
 
 		if len(query.Params) == 1 {
@@ -862,7 +864,8 @@ import (
 
 {{range .GoQueries}}
 {{if eq .SourceName $.SourceName}}
-const {{.ConstantName}} = {{$.Q}}{{.SQL}}
+const {{.ConstantName}} = {{$.Q}}-- name: {{.MethodName}} {{.Cmd}}
+{{.SQL}}
 {{$.Q}}
 
 {{if .Arg.EmitStruct}}
@@ -880,6 +883,7 @@ type {{.Ret.Type}} struct { {{- range .Ret.Struct.Fields}}
 {{end}}
 
 {{if eq .Cmd ":one"}}
+{{range .Comments}}//{{.}}{{end}}
 func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ({{.Ret.Type}}, error) {
   	{{- if $.EmitPreparedQueries}}
 	row := q.queryRow(ctx, q.{{.FieldName}}, {{.ConstantName}}, {{.Arg.Params}})
@@ -893,6 +897,7 @@ func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ({{.Ret.Ty
 {{end}}
 
 {{if eq .Cmd ":many"}}
+{{range .Comments}}//{{.}}{{end}}
 func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ([]{{.Ret.Type}}, error) {
   	{{- if $.EmitPreparedQueries}}
 	rows, err := q.query(ctx, q.{{.FieldName}}, {{.ConstantName}}, {{.Arg.Params}})
@@ -922,6 +927,7 @@ func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ([]{{.Ret.
 {{end}}
 
 {{if eq .Cmd ":exec"}}
+{{range .Comments}}//{{.}}{{end}}
 func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) error {
   	{{- if $.EmitPreparedQueries}}
 	_, err := q.exec(ctx, q.{{.FieldName}}, {{.ConstantName}}, {{.Arg.Params}})
@@ -933,6 +939,7 @@ func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) error {
 {{end}}
 
 {{if eq .Cmd ":execrows"}}
+{{range .Comments}}//{{.}}{{end}}
 func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) (int64, error) {
   	{{- if $.EmitPreparedQueries}}
 	result, err := q.exec(ctx, q.{{.FieldName}}, {{.ConstantName}}, {{.Arg.Params}})

internal/dinosql/parser.go

@@ -1,6 +1,7 @@
 package dinosql
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -153,11 +154,12 @@ type Parameter struct {
 // Name and Cmd may be empty
 // Maybe I don't need the SQL string if I have the raw Stmt?
 type Query struct {
-	SQL     string
-	Columns []core.Column
-	Params  []Parameter
-	Name    string
-	Cmd     string // TODO: Pick a better name. One of: one, many, exec, execrows
+	SQL      string
+	Columns  []core.Column
+	Params   []Parameter
+	Name     string
+	Cmd      string // TODO: Pick a better name. One of: one, many, exec, execrows
+	Comments []string
 
 	// XXX: Hack
 	NeedsEdit bool
@@ -409,16 +411,38 @@ func parseQuery(c core.Catalog, stmt nodes.Node, source string) (*Query, error)
 		return nil, err
 	}
 
+	trimmed, comments, err := stripComments(rawSQL)
+	if err != nil {
+		return nil, err
+	}
+
 	return &Query{
 		Cmd:       cmd,
+		Comments:  comments,
 		Name:      name,
 		Params:    params,
 		Columns:   cols,
-		SQL:       rawSQL,
+		SQL:       trimmed,
 		NeedsEdit: needsEdit(stmt),
 	}, nil
 }
 
+func stripComments(sql string) (string, []string, error) {
+	s := bufio.NewScanner(strings.NewReader(sql))
+	var lines, comments []string
+	for s.Scan() {
+		if strings.HasPrefix(s.Text(), "-- name:") {
+			continue
+		}
+		if strings.HasPrefix(s.Text(), "--") {
+			comments = append(comments, strings.TrimPrefix(s.Text(), "--"))
+			continue
+		}
+		lines = append(lines, s.Text())
+	}
+	return strings.Join(lines, "\n"), comments, s.Err()
+}
+
 type QueryCatalog struct {
 	catalog core.Catalog
 	ctes    map[string]core.Table

internal/dinosql/testdata/ondeck/city.sql.go

@@ -9,6 +9,7 @@ FROM city
 WHERE slug = $1;
 
 -- name: CreateCity :one
+-- Create a new city. The slug must be unique
 INSERT INTO city (
     name,
     slug