file: add HasSection method (#308)

Co-authored-by: Joe Chen <jc@unknwon.io>

file.go

@@ -142,6 +142,12 @@ func (f *File) GetSection(name string) (*Section, error) {
 	return secs[0], err
 }
 
+// HasSection returns true if the file contains a section with given name.
+func (f *File) HasSection(name string) bool {
+	section, _ := f.GetSection(name)
+	return section != nil
+}
+
 // SectionsByName returns all sections with given name.
 func (f *File) SectionsByName(name string) ([]*Section, error) {
 	if len(name) == 0 {

file_test.go

@@ -237,6 +237,20 @@ func TestFile_GetSection(t *testing.T) {
 	})
 }
 
+func TestFile_HasSection(t *testing.T) {
+	f, err := Load(fullConf)
+	require.NoError(t, err)
+	require.NotNil(t, f)
+
+	sec := f.HasSection("author")
+	assert.True(t, sec)
+
+	t.Run("section not exists", func(t *testing.T) {
+		nonexistent := f.HasSection("404")
+		assert.False(t, nonexistent)
+	})
+}
+
 func TestFile_Section(t *testing.T) {
 	t.Run("get a section", func(t *testing.T) {
 		f, err := Load(fullConf)