add layout for testing OSCBundle error cases

bundle.go

@@ -34,11 +34,11 @@ func (b *OSCBundle) ToBytes() ([]byte, error) {
 
 func BundleFromBytes(bytes []byte) (*OSCBundle, []byte, error) {
 	if len(bytes) < 20 {
-		return nil, bytes, errors.New("bundle has to be at least 20 bytes")
+		return nil, bytes, errors.New("OSC Bundle has to be at least 20 bytes")
 	}
 
 	if bytes[0] != 35 {
-		return nil, bytes, errors.New("bundle must start with a #")
+		return nil, bytes, errors.New("OSC Bundle must start with a #")
 	}
 
 	bundleHeader, bytesAfterBundleHeader, err := readOSCString(bytes)
@@ -48,7 +48,7 @@ func BundleFromBytes(bytes []byte) (*OSCBundle, []byte, error) {
 	}
 
 	if bundleHeader != "#bundle" {
-		return nil, bytesAfterBundleHeader, errors.New("bundle must start with #bundle string")
+		return nil, bytesAfterBundleHeader, errors.New("OSC Bundle must start with #bundle string")
 	}
 
 	timeTag, bytesAfterTimeTag, err := readOSCTimeTag(bytesAfterBundleHeader)

bundle_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestOSCBundleEncoding(t *testing.T) {
+func TestGoodOSCBundleEncoding(t *testing.T) {
 
 	testCases := []struct {
 		name     string
@@ -13,15 +13,15 @@ func TestOSCBundleEncoding(t *testing.T) {
 		expected []byte
 	}{
 		{
-			"simple contents single message",
-			&OSCBundle{
+			name: "simple contents single message",
+			bundle: &OSCBundle{
 				TimeTag: OSCTimeTag{
 					seconds:           32,
 					fractionalSeconds: 0,
 				},
 				Contents: []OSCPacket{&OSCMessage{Address: "/oscillator/4/frequency", Args: []OSCArg{{Type: "f", Value: float32(440)}}}},
 			},
-			[]byte{35, 98, 117, 110, 100, 108, 101, 0, 0, 0, 0,
+			expected: []byte{35, 98, 117, 110, 100, 108, 101, 0, 0, 0, 0,
 				32, 0, 0, 0, 0, 0, 0, 0, 32, 47, 111,
 				115, 99, 105, 108, 108, 97, 116, 111, 114, 47, 52,
 				47, 102, 114, 101, 113, 117, 101, 110, 99, 121, 0,
@@ -45,7 +45,31 @@ func TestOSCBundleEncoding(t *testing.T) {
 	}
 }
 
-func TestOSCBundleDecoding(t *testing.T) {
+func TestBadOSCBundleEncoding(t *testing.T) {
+
+	testCases := []struct {
+		name        string
+		bundle      *OSCBundle
+		errorString string
+	}{}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+
+			got, err := testCase.bundle.ToBytes()
+
+			if err == nil {
+				t.Fatalf("OSCBundle.ToBytes() expected to fail but got: %+v", got)
+			}
+
+			if err.Error() != testCase.errorString {
+				t.Fatalf("OSCBundle.ToBytes() got error '%s', expected '%s'", err.Error(), testCase.errorString)
+			}
+		})
+	}
+}
+
+func TestGoodOSCBundleDecoding(t *testing.T) {
 	testCases := []struct {
 		name     string
 		expected *OSCBundle
@@ -86,3 +110,48 @@ func TestOSCBundleDecoding(t *testing.T) {
 		})
 	}
 }
+
+func TestBadOSCBundleDecoding(t *testing.T) {
+	testCases := []struct {
+		name        string
+		bytes       []byte
+		errorString string
+	}{
+		{
+			name:        "empty byte array",
+			bytes:       []byte{},
+			errorString: "OSC Bundle has to be at least 20 bytes",
+		},
+		{
+			name:        "does not start with #",
+			bytes:       []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+			errorString: "OSC Bundle must start with a #",
+		},
+		{
+			name:        "does not start with #bundle",
+			bytes:       []byte{35, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+			errorString: "OSC Bundle must start with #bundle string",
+		},
+		{
+			name: "bundle header not properly null terminated",
+			bytes: []byte{35, 98, 117, 110, 100, 108, 101, 35, 0, 0, 0,
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				0, 0, 0, 0},
+			errorString: "OSC Bundle must start with #bundle string",
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			got, _, err := BundleFromBytes(testCase.bytes)
+
+			if err == nil {
+				t.Fatalf("BundleFromBytes expected to fail but got: %+v", got)
+			}
+
+			if err.Error() != testCase.errorString {
+				t.Fatalf("BundleFromBytes got error '%s', expected '%s'", err.Error(), testCase.errorString)
+			}
+		})
+	}
+}