Small increase in test coverage

Improving test coverage

Change-Id: I0e4da35f24b16d143cf0e4045182ae7d93d13b1c

go.sum

@@ -478,6 +478,7 @@ github.com/spf13/viper v1.0.2 h1:Ncr3ZIuJn322w2k1qmzXDnkLAdQMlJqBa9kfAH+irso=
 github.com/spf13/viper v1.0.2/go.mod h1:A8kyI5cUJhb8N+3pkfONlcEcZbueH6nhAm0Fq7SrnBM=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
 github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v0.0.0-20151208002404-e3a8ff8ce365/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=

pkg/util/yaml/writer.go

@@ -6,6 +6,13 @@ import (
 	"sigs.k8s.io/yaml"
 )
 
+const (
+	// DotYamlSeparator yaml separator
+	DotYamlSeparator = "...\n"
+	// DashYamlSeparator yaml separator
+	DashYamlSeparator = "---\n"
+)
+
 // WriteOut dumps any yaml competible document to writer, adding yaml separator `---`
 // at the beginning of the document, and `...` at the end
 func WriteOut(dst io.Writer, src interface{}) error {
@@ -15,7 +22,7 @@ func WriteOut(dst io.Writer, src interface{}) error {
 		return err
 	}
 	// add separator for each document
-	_, err = dst.Write([]byte("---\n"))
+	_, err = dst.Write([]byte(DashYamlSeparator))
 	if err != nil {
 		return err
 	}
@@ -24,7 +31,7 @@ func WriteOut(dst io.Writer, src interface{}) error {
 		return err
 	}
 	// add separator for each document
-	_, err = dst.Write([]byte("...\n"))
+	_, err = dst.Write([]byte(DotYamlSeparator))
 	if err != nil {
 		return err
 	}

pkg/util/yaml/writer_test.go

@@ -2,6 +2,7 @@ package yaml_test
 
 import (
 	"bytes"
+	"io"
 	"regexp"
 	"testing"
 	"time"
@@ -13,6 +14,25 @@ import (
 	utilyaml "opendev.org/airship/airshipctl/pkg/util/yaml"
 )
 
+// FakeYaml Used to emulate yaml
+type FakeYaml struct {
+	Key string
+}
+
+// FakeErrorDashWriter fake object to simulate errors of writer
+type FakeErrorDashWriter struct {
+	Err   error
+	Match string
+}
+
+func (f *FakeErrorDashWriter) Write(b []byte) (int, error) {
+	if string(b) == f.Match {
+		// arbitrary error from io package
+		return 0, f.Err
+	}
+	return len(b), nil
+}
+
 func TestWriteOut(t *testing.T) {
 
 	// Create some object, that can be marshaled into yaml
@@ -53,3 +73,26 @@ func TestWriteOut(t *testing.T) {
 	// Compare original object with reverse marshaled
 	assert.Equal(t, ob, &rob)
 }
+
+func TestWriteOutErrorsWrongYaml(t *testing.T) {
+	src := make(chan int)
+	var b bytes.Buffer
+	assert.Error(t, utilyaml.WriteOut(&b, src))
+}
+
+func TestWriteOutErrorsErrorWriter(t *testing.T) {
+	// Some easy to match yaml
+	fakeYaml := FakeYaml{Key: "value"}
+	fakeWriter := &FakeErrorDashWriter{Err: io.ErrUnexpectedEOF}
+
+	strings := []string{
+		utilyaml.DotYamlSeparator,
+		utilyaml.DashYamlSeparator,
+		"Key: value\n",
+	}
+	for _, str := range strings {
+		fakeWriter.Match = str
+		assert.Error(t, utilyaml.WriteOut(fakeWriter, fakeYaml))
+
+	}
+}