isStructPtr and unmarshal functions

confection.go

@@ -0,0 +1,29 @@
+package confection2
+
+import (
+	"encoding/json"
+	"reflect"
+)
+
+var (
+	// config stores application config.
+	config interface{}
+)
+
+func isStructPtr(target interface{}) bool {
+	if val := reflect.ValueOf(target); val.Kind() == reflect.Ptr {
+		if val = reflect.Indirect(val); val.Kind() == reflect.Struct {
+			return true
+		}
+	}
+
+	return false
+}
+
+func unmarshal(body []byte, target interface{}) error {
+	if err := json.Unmarshal(body, target); err != nil {
+		return err
+	}
+
+	return nil
+}

confection_test.go

@@ -0,0 +1,44 @@
+package confection2
+
+import "testing"
+
+type testConf struct {
+	Foo string `json:"foo"`
+	Bar int    `json:"bar"`
+}
+
+const (
+	goodJSON = `{"foo": "baz", "bar": 1}`
+	badJSON  = `{"foo": "noooo...`
+)
+
+func TestIsStructPtr(t *testing.T) {
+	if ok := isStructPtr(1); ok {
+		t.Error("Integer recognized as a struct pointer")
+	}
+	if ok := isStructPtr(testConf{}); ok {
+		t.Error("Struct instance recognized as a struct pointer")
+	}
+	if ok := isStructPtr(&testConf{}); !ok {
+		t.Error("Struct pointer was not recognized")
+	}
+}
+
+func TestUnmarshal(t *testing.T) {
+	conf := testConf{}
+	var i interface{} = &conf
+
+	if err := unmarshal([]byte(badJSON), i); err == nil {
+		t.Error("Expected error")
+	}
+
+	if err := unmarshal([]byte(goodJSON), i); err != nil {
+		t.Error("Unexpected error")
+	}
+	if conf.Foo != "baz" {
+		t.Errorf("Expected Foo to equal %q, got %q", "baz", conf.Foo)
+	}
+	if conf.Bar != 1 {
+		t.Errorf("Expected Bar to equal %q, got %q", 1, conf.Bar)
+	}
+}