Added marshalling tests based on json mock files

tests/mocks/empty.json

@@ -0,0 +1 @@
+{}

tests/unmarshalling_test.go

@@ -0,0 +1,83 @@
+package tests
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"testing"
+
+	a "activitypub"
+	j "jsonld"
+)
+
+const dir = "./mocks"
+
+var stopOnFailure = false
+
+type testPair struct {
+	path     string
+	expected bool
+	blank    a.ObjectOrLink
+	result   a.ObjectOrLink
+}
+
+type tests map[string]testPair
+
+var allTests tests = tests{
+	"nil": testPair{
+		path:     "./mocks/empty.json",
+		expected: true,
+		blank:    a.Object{},
+		result:   a.Object{},
+	},
+}
+
+func getFileContents(path string) []byte {
+	f, _ := os.Open(path)
+
+	data := make([]byte, 512)
+	io.ReadFull(f, data)
+	data = bytes.Trim(data, "\x00")
+
+	return data
+}
+
+func Test_ActivityPubUnmarshall(t *testing.T) {
+	var err error
+
+	var f = t.Errorf
+	if stopOnFailure {
+		f = t.Fatalf
+	}
+
+	if len(allTests) == 0 {
+		t.Skip("No tests found")
+	}
+
+	for _, pair := range allTests {
+		fmt.Printf("===          %s\n", pair.path)
+
+		data := getFileContents(pair.path)
+
+		object := pair.blank
+
+		err = j.Unmarshal(data, object)
+		if err != nil {
+			f("Error: %s", err)
+			continue
+		}
+		expLbl := ""
+		if !pair.expected {
+			expLbl = "not be "
+		}
+		if pair.expected != reflect.DeepEqual(object, pair.result) {
+			f("\n%#v\n should %sequal to\n%#v", object, expLbl, pair.result)
+			continue
+		}
+		if err == nil {
+			fmt.Print("---          PASS\n")
+		}
+	}
+}