error-action: add marshal yaml

lib/workflow/job.go

@@ -16,6 +16,10 @@ type Job struct {
 
 type ErrorAction string
 
+func (er ErrorAction) MarshalYAML() (interface{}, error) {
+	return er.String(), nil
+}
+
 func (ea *ErrorAction) UnmarshalYAML(value *yaml.Node) error {
 	if value.IsZero() {
 		*ea = ErrorActionStopJob

lib/workflow/job_test.go

@@ -88,3 +88,45 @@ func TestErrorAction_UnmarshalYAML(t *testing.T) {
 		})
 	}
 }
+
+func TestErrorAction_MarshalYAML(t *testing.T) {
+	tests := []struct {
+		name string
+		er   ErrorAction
+		want []byte
+	}{
+		{
+			name: "continue",
+			er:   ErrorActionContinue,
+			want: []byte("E: continue"),
+		},
+		{
+			name: "stop-job",
+			er:   ErrorActionStopJob,
+			want: []byte("E: stop-job"),
+		},
+		{
+			name: "stop-action",
+			er:   ErrorActionStopAction,
+			want: []byte("E: stop-action"),
+		},
+		{
+			name: "stop-run",
+			er:   ErrorActionStopRun,
+			want: []byte("E: stop-run"),
+		},
+	}
+	type placeholder struct {
+		E ErrorAction `yaml:"E"`
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			e := placeholder{E: tt.er}
+			got, err := yaml.Marshal(e)
+			if !assert.NoError(t, err) {
+				return
+			}
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}