diff --git a/api/core/span_context_test.go b/api/core/span_context_test.go
new file mode 100644
index 000000000..a8e15d055
--- /dev/null
+++ b/api/core/span_context_test.go
@@ -0,0 +1,137 @@
+// Copyright 2019, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package core
+
+import (
+	"testing"
+)
+
+func TestHasTraceID(t *testing.T) {
+	for _, testcase := range []struct {
+		name string
+		tid  TraceID
+		want bool
+	}{
+		{
+			name: "both",
+			tid:  TraceID{High: uint64(42), Low: uint64(42)},
+			want: true,
+		}, {
+			name: "neither",
+			tid:  TraceID{},
+			want: false,
+		}, {
+			name: "high",
+			tid:  TraceID{High: uint64(42)},
+			want: true,
+		}, {
+			name: "low",
+			tid:  TraceID{Low: uint64(42)},
+			want: true,
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			//proto: func (sc SpanContext) HasTraceID() bool{}
+			sc := SpanContext{TraceID: testcase.tid}
+			have := sc.HasTraceID()
+			if have != testcase.want {
+				t.Errorf("Want: %v, but have: %v", testcase.want, have)
+			}
+		})
+	}
+}
+
+func TestHasSpanID(t *testing.T) {
+	for _, testcase := range []struct {
+		name string
+		sc   SpanContext
+		want bool
+	}{
+		{
+			name: "has",
+			sc:   SpanContext{SpanID: uint64(42)},
+			want: true,
+		}, {
+			name: "hasnt",
+			sc:   SpanContext{},
+			want: false,
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			//proto: func (sc SpanContext) HasSpanID() bool {}
+			have := testcase.sc.HasSpanID()
+			if have != testcase.want {
+				t.Errorf("Want: %v, but have: %v", testcase.want, have)
+			}
+		})
+	}
+}
+
+func TestSpanIDString(t *testing.T) {
+	for _, testcase := range []struct {
+		name string
+		sc   SpanContext
+		want string
+	}{
+		{
+			name: "fourtytwo",
+			sc:   SpanContext{SpanID: uint64(42)},
+			want: `000..02a`,
+		}, {
+			name: "empty",
+			sc:   SpanContext{},
+			want: `000..000`,
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			//proto: func (sc SpanContext) SpanIDString() string {}
+			have := testcase.sc.SpanIDString()
+			if have != testcase.want {
+				t.Errorf("Want: %s, but have: %s", testcase.want, have)
+			}
+		})
+	}
+}
+
+func TestTraceIDString(t *testing.T) {
+	for _, testcase := range []struct {
+		name string
+		sc   SpanContext
+		want string
+	}{
+		{
+			name: "fourtytwo",
+			sc: SpanContext{
+				TraceID: TraceID{
+					High: uint64(42),
+					Low:  uint64(42),
+				},
+			},
+			want: `000..02a`,
+		}, {
+			name: "empty",
+			sc:   SpanContext{TraceID: TraceID{}},
+			want: `000..000`,
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			//proto: func (sc SpanContext) TraceIDString() string {}
+			have := testcase.sc.TraceIDString()
+			if have != testcase.want {
+				t.Errorf("Want: %s, but have: %s", testcase.want, have)
+			}
+		})
+	}
+}