fix: brew dependency: string or struct (#1559)

Signed-off-by: Carlos Alexandro Becker <caarlos0@gmail.com>

pkg/config/config.go

@@ -45,6 +45,28 @@ type HomebrewDependency struct {
 	Type string `yaml:",omitempty"`
 }
 
+// type alias to prevent stack overflowing in the custom unmarshaler
+type homebrewDependency HomebrewDependency
+
+// UnmarshalYAML is a custom unmarshaler that accept brew deps in both the old and new format.
+func (a *HomebrewDependency) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var str string
+	if err := unmarshal(&str); err == nil {
+		a.Name = str
+		return nil
+	}
+
+	var dep homebrewDependency
+	if err := unmarshal(&dep); err != nil {
+		return err
+	}
+
+	a.Name = dep.Name
+	a.Type = dep.Type
+
+	return nil
+}
+
 // String of the repo, e.g. owner/name
 func (r Repo) String() string {
 	if r.Owner == "" && r.Name == "" {

pkg/config/config_homebrew_dependency_test.go

@@ -0,0 +1,72 @@
+package config
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestUnmarshalHomebrewDependency(t *testing.T) {
+	t.Run("string arr", func(t *testing.T) {
+		var conf = `
+brews:
+- name: foo
+  dependencies:
+  - foo
+  - bar
+`
+		buf := strings.NewReader(conf)
+		prop, err := LoadReader(buf)
+
+		require.NoError(t, err)
+		require.Equal(t, []HomebrewDependency{
+			{
+				Name: "foo",
+			}, {
+				Name: "bar",
+			},
+		}, prop.Brews[0].Dependencies)
+	})
+
+	t.Run("mixed", func(t *testing.T) {
+		var conf = `
+brews:
+- name: foo
+  dependencies:
+  - name: foo
+  - bar
+  - name: foobar
+    type: optional
+`
+		buf := strings.NewReader(conf)
+		prop, err := LoadReader(buf)
+
+		require.NoError(t, err)
+		require.Equal(t, []HomebrewDependency{
+			{
+				Name: "foo",
+			}, {
+				Name: "bar",
+			}, {
+				Name: "foobar",
+				Type: "optional",
+			},
+		}, prop.Brews[0].Dependencies)
+	})
+
+	t.Run("mixed", func(t *testing.T) {
+		var conf = `
+brews:
+- name: foo
+  dependencies:
+  - name: foo
+  - namer: bar
+  - asdda
+`
+		buf := strings.NewReader(conf)
+		_, err := LoadReader(buf)
+
+		require.EqualError(t, err, "yaml: unmarshal errors:\n  line 6: field namer not found in type config.homebrewDependency")
+	})
+}