add custom bool true type

yaml/types/bool.go

@@ -0,0 +1,28 @@
+package types
+
+import "strconv"
+
+// BoolTrue is a custom Yaml boolean type that defaults to true.
+type BoolTrue struct {
+	value bool
+}
+
+// UnmarshalYAML implements custom Yaml unmarshaling.
+func (b *BoolTrue) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var s string
+	err := unmarshal(&s)
+	if err != nil {
+		return err
+	}
+
+	b.value, err = strconv.ParseBool(s)
+	if err != nil {
+		b.value = true
+	}
+	return nil
+}
+
+// Bool returns the bool value.
+func (b BoolTrue) Bool() bool {
+	return b.value
+}

yaml/types/bool_test.go

@@ -0,0 +1,54 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/franela/goblin"
+	"gopkg.in/yaml.v2"
+)
+
+func TestBoolTrue(t *testing.T) {
+	g := goblin.Goblin(t)
+
+	g.Describe("Yaml bool type", func() {
+		g.Describe("given a yaml file", func() {
+
+			g.It("should unmarshal true", func() {
+				in := []byte("true")
+				out := BoolTrue{}
+				err := yaml.Unmarshal(in, &out)
+				if err != nil {
+					g.Fail(err)
+				}
+				g.Assert(out.Bool()).Equal(true)
+			})
+
+			g.It("should unmarshal false", func() {
+				in := []byte("false")
+				out := BoolTrue{}
+				err := yaml.Unmarshal(in, &out)
+				if err != nil {
+					g.Fail(err)
+				}
+				g.Assert(out.Bool()).Equal(false)
+			})
+
+			g.It("should unmarshal true when empty", func() {
+				in := []byte("")
+				out := BoolTrue{}
+				err := yaml.Unmarshal(in, &out)
+				if err != nil {
+					g.Fail(err)
+				}
+				g.Assert(out.Bool()).Equal(false)
+			})
+
+			g.It("should throw error when invalid", func() {
+				in := []byte("{ }") // string value should fail parse
+				out := BoolTrue{}
+				err := yaml.Unmarshal(in, &out)
+				g.Assert(err != nil).IsTrue("expects error")
+			})
+		})
+	})
+}