fix(goctl): api format with reader input (#1722)

resolves #1721

tools/goctl/api/format/format_test.go

@@ -1,15 +1,21 @@
 package format
 
 import (
+	"fmt"
+	"io/fs"
+	"io/ioutil"
+	"os"
+	"path"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 const (
 	notFormattedStr = `
 type Request struct {
-  Name string ` + "`" + `path:"name,options=you|me"` + "`" + `  
+  Name string ` + "`" + `path:"name,options=you|me"` + "`" + `
 }
 type Response struct {
   Message string ` + "`" + `json:"message"` + "`" + `
@@ -45,3 +51,26 @@ func TestFormat(t *testing.T) {
 	_, err = apiFormat(notFormattedStr, false)
 	assert.Errorf(t, err, " line 7:13 can not found declaration 'Student' in context")
 }
+
+func Test_apiFormatReader_issue1721(t *testing.T) {
+	dir, err := os.MkdirTemp("", "goctl-api-format")
+	require.NoError(t, err)
+	defer os.RemoveAll(dir)
+	subDir := path.Join(dir, "sub")
+	err = os.MkdirAll(subDir, fs.ModePerm)
+	require.NoError(t, err)
+
+	importedFilename := path.Join(dir, "foo.api")
+	err = ioutil.WriteFile(importedFilename, []byte{}, fs.ModePerm)
+	require.NoError(t, err)
+
+	filename := path.Join(subDir, "bar.api")
+	err = ioutil.WriteFile(filename, []byte(fmt.Sprintf(`import "%s"`, importedFilename)), 0644)
+	require.NoError(t, err)
+
+	f, err := os.Open(filename)
+	require.NoError(t, err)
+
+	err = apiFormatReader(f, filename, false)
+	assert.NoError(t, err)
+}