Implemented missing AsYaml methods and added tests

Author: cmaglie

Diff for: arduino/sketch/profiles.go

@@ -76,7 +76,7 @@ type ProfileRequiredPlatforms []*ProfilePlatformReference
 
 // AsYaml outputs the required platforms as Yaml
 func (p *ProfileRequiredPlatforms) AsYaml() string {
-	res := ""
+	res := "    platforms:\n"
 	for _, platform := range *p {
 		res += platform.AsYaml()
 	}
@@ -89,7 +89,11 @@ type ProfileRequiredLibraries []*ProfileLibraryReference
 
 // AsYaml outputs the required libraries as Yaml
 func (p *ProfileRequiredLibraries) AsYaml() string {
-	return ""
+	res := "    libraries:\n"
+	for _, lib := range *p {
+		res += lib.AsYaml()
+	}
+	return res
 }
 
 // ProfilePlatformReference is a reference to a platform
@@ -187,6 +191,12 @@ func (l *ProfileLibraryReference) UnmarshalYAML(unmarshal func(interface{}) erro
 	return nil
 }
 
+// AsYaml outputs the required library as Yaml
+func (l *ProfileLibraryReference) AsYaml() string {
+	res := fmt.Sprintf("      - %s (%s)\n", l.Library, l.Version)
+	return res
+}
+
 func (l *ProfileLibraryReference) String() string {
 	return fmt.Sprintf("%s@%s", l.Library, l.Version)
 }

Diff for: arduino/sketch/profiles_test.go

@@ -24,7 +24,11 @@ import (
 )
 
 func TestProjectFileLoading(t *testing.T) {
-	proj, err := LoadProjectFile(paths.New("testdata", "SketchWithProfiles", "sketch.yml"))
+	sketchProj := paths.New("testdata", "SketchWithProfiles", "sketch.yml")
+	proj, err := LoadProjectFile(sketchProj)
 	require.NoError(t, err)
 	fmt.Println(proj)
+	golden, err := sketchProj.ReadFile()
+	require.NoError(t, err)
+	require.Equal(t, proj.AsYaml(), string(golden))
 }