Add negative tests for MsgVersion.

This commit adds tests for the error paths when encoding and decoding
MsgVersion.

msgversion_test.go

@@ -8,8 +8,10 @@ import (
 	"bytes"
 	"github.com/conformal/btcwire"
 	"github.com/davecgh/go-spew/spew"
+	"io"
 	"net"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 )
@@ -225,6 +227,112 @@ func TestVersionWire(t *testing.T) {
 	}
 }
 
+// TestVersionWireErrors performs negative tests against wire encode and
+// decode of MsgGetHeaders to confirm error paths work correctly.
+func TestVersionWireErrors(t *testing.T) {
+	// Use protocol version 60002 specifically here instead of the latest
+	// because the test data is using bytes encoded with that protocol
+	// version.
+	pver := uint32(60002)
+	btcwireErr := &btcwire.MessageError{}
+
+	// Copy the base version and change the user agent to exceed max limits.
+	bvc := *baseVersion
+	exceedUAVer := &bvc
+	newUA := "/" + strings.Repeat("t", btcwire.MaxUserAgentLen-8+1) + ":0.0.1/"
+	exceedUAVer.UserAgent = newUA
+
+	// Encode the new UA length as a varint.
+	var newUAVarIntBuf bytes.Buffer
+	err := btcwire.TstWriteVarInt(&newUAVarIntBuf, pver, uint64(len(newUA)))
+	if err != nil {
+		t.Errorf("writeVarInt: error %v", err)
+	}
+
+	// Make a new buffer big enough to hold the base version plus the new
+	// bytes for the bigger varint to hold the new size of the user agent
+	// and the new user agent string.  Then stich it all together.
+	newLen := len(baseVersionEncoded) - len(baseVersion.UserAgent)
+	newLen = newLen + len(newUAVarIntBuf.Bytes()) - 1 + len(newUA)
+	exceedUAVerEncoded := make([]byte, newLen)
+	copy(exceedUAVerEncoded, baseVersionEncoded[0:80])
+	copy(exceedUAVerEncoded[80:], newUAVarIntBuf.Bytes())
+	copy(exceedUAVerEncoded[83:], []byte(newUA))
+	copy(exceedUAVerEncoded[83+len(newUA):], baseVersionEncoded[97:100])
+
+	tests := []struct {
+		in       *btcwire.MsgVersion // Value to encode
+		buf      []byte              // Wire encoding
+		pver     uint32              // Protocol version for wire encoding
+		max      int                 // Max size of fixed buffer to induce errors
+		writeErr error               // Expected write error
+		readErr  error               // Expected read error
+	}{
+		// Force error in protocol version.
+		{baseVersion, baseVersionEncoded, pver, 0, io.ErrShortWrite, io.EOF},
+		// Force error in services.
+		{baseVersion, baseVersionEncoded, pver, 4, io.ErrShortWrite, io.EOF},
+		// Force error in timestamp.
+		{baseVersion, baseVersionEncoded, pver, 12, io.ErrShortWrite, io.EOF},
+		// Force error in remote address.
+		{baseVersion, baseVersionEncoded, pver, 20, io.ErrShortWrite, io.EOF},
+		// Force error in local address.
+		{baseVersion, baseVersionEncoded, pver, 46, io.ErrShortWrite, io.EOF},
+		// Force error in nonce.
+		{baseVersion, baseVersionEncoded, pver, 72, io.ErrShortWrite, io.EOF},
+		// Force error in user agent length.
+		{baseVersion, baseVersionEncoded, pver, 80, io.ErrShortWrite, io.EOF},
+		// Force error in user agent.
+		{baseVersion, baseVersionEncoded, pver, 81, io.ErrShortWrite, io.EOF},
+		// Force error in last block.
+		{baseVersion, baseVersionEncoded, pver, 97, io.ErrShortWrite, io.EOF},
+		// Force error due to user agent too big.
+		{exceedUAVer, exceedUAVerEncoded, pver, newLen, btcwireErr, btcwireErr},
+	}
+
+	t.Logf("Running %d tests", len(tests))
+	for i, test := range tests {
+		// Encode to wire format.
+		w := newFixedWriter(test.max)
+		err := test.in.BtcEncode(w, test.pver)
+		if reflect.TypeOf(err) != reflect.TypeOf(test.writeErr) {
+			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
+				i, err, test.writeErr)
+			continue
+		}
+
+		// For errors which are not of type btcwire.MessageError, check
+		// them for equality.
+		if _, ok := err.(*btcwire.MessageError); !ok {
+			if err != test.writeErr {
+				t.Errorf("BtcEncode #%d wrong error got: %v, "+
+					"want: %v", i, err, test.writeErr)
+				continue
+			}
+		}
+
+		// Decode from wire format.
+		var msg btcwire.MsgVersion
+		r := newFixedReader(test.max, test.buf)
+		err = msg.BtcDecode(r, test.pver)
+		if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
+			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
+				i, err, test.readErr)
+			continue
+		}
+
+		// For errors which are not of type btcwire.MessageError, check
+		// them for equality.
+		if _, ok := err.(*btcwire.MessageError); !ok {
+			if err != test.readErr {
+				t.Errorf("BtcDecode #%d wrong error got: %v, "+
+					"want: %v", i, err, test.readErr)
+				continue
+			}
+		}
+	}
+}
+
 // baseVersion is used in the various tests as a baseline MsgVersion.
 var baseVersion *btcwire.MsgVersion = &btcwire.MsgVersion{
 	ProtocolVersion: 60002,

test_coverage.txt

@@ -1,10 +1,12 @@
 
 github.com/conformal/btcwire/message.go		 ReadMessage				 100.00% (37/37)
 github.com/conformal/btcwire/message.go		 WriteMessage				 100.00% (27/27)
+github.com/conformal/btcwire/msgversion.go	 MsgVersion.BtcDecode			 100.00% (25/25)
 github.com/conformal/btcwire/msgtx.go		 MsgTx.Copy				 100.00% (24/24)
 github.com/conformal/btcwire/common.go		 readVarInt				 100.00% (24/24)
-github.com/conformal/btcwire/message.go		 makeEmptyMessage			 100.00% (20/20)
+github.com/conformal/btcwire/msgversion.go	 MsgVersion.BtcEncode			 100.00% (22/22)
 github.com/conformal/btcwire/netaddress.go	 readNetAddress				 100.00% (20/20)
+github.com/conformal/btcwire/message.go		 makeEmptyMessage			 100.00% (20/20)
 github.com/conformal/btcwire/msggetblocks.go	 MsgGetBlocks.BtcDecode			 100.00% (19/19)
 github.com/conformal/btcwire/msggetheaders.go	 MsgGetHeaders.BtcDecode		 100.00% (19/19)
 github.com/conformal/btcwire/msggetblocks.go	 MsgGetBlocks.BtcEncode			 100.00% (18/18)
@@ -12,35 +14,34 @@ github.com/conformal/btcwire/msggetheaders.go	 MsgGetHeaders.BtcEncode		 100.00%
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.BtcDecodeTxLoc		 100.00% (16/16)
 github.com/conformal/btcwire/common.go		 writeVarInt				 100.00% (16/16)
 github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.BtcDecode			 100.00% (16/16)
+github.com/conformal/btcwire/shahash.go		 NewShaHashFromStr			 100.00% (15/15)
 github.com/conformal/btcwire/msgaddr.go		 MsgAddr.BtcEncode			 100.00% (15/15)
 github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.BtcEncode			 100.00% (15/15)
-github.com/conformal/btcwire/shahash.go		 NewShaHashFromStr			 100.00% (15/15)
 github.com/conformal/btcwire/netaddress.go	 writeNetAddress			 100.00% (14/14)
-github.com/conformal/btcwire/msginv.go		 MsgInv.BtcDecode			 100.00% (13/13)
 github.com/conformal/btcwire/msggetdata.go	 MsgGetData.BtcDecode			 100.00% (13/13)
+github.com/conformal/btcwire/msginv.go		 MsgInv.BtcDecode			 100.00% (13/13)
 github.com/conformal/btcwire/msgnotfound.go	 MsgNotFound.BtcDecode			 100.00% (13/13)
 github.com/conformal/btcwire/msgaddr.go		 MsgAddr.BtcDecode			 100.00% (13/13)
 github.com/conformal/btcwire/msginv.go		 MsgInv.BtcEncode			 100.00% (12/12)
 github.com/conformal/btcwire/msggetdata.go	 MsgGetData.BtcEncode			 100.00% (12/12)
-github.com/conformal/btcwire/msgnotfound.go	 MsgNotFound.BtcEncode			 100.00% (12/12)
 github.com/conformal/btcwire/protocol.go	 ServiceFlag.String			 100.00% (12/12)
+github.com/conformal/btcwire/msgnotfound.go	 MsgNotFound.BtcEncode			 100.00% (12/12)
+github.com/conformal/btcwire/message.go		 discardInput				 100.00% (10/10)
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.BtcDecode			 100.00% (10/10)
 github.com/conformal/btcwire/blockheader.go	 readBlockHeader			 100.00% (10/10)
-github.com/conformal/btcwire/message.go		 discardInput				 100.00% (10/10)
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.BtcEncode			 100.00% (9/9)
-github.com/conformal/btcwire/msgalert.go	 MsgAlert.BtcEncode			 100.00% (8/8)
-github.com/conformal/btcwire/blockheader.go	 writeBlockHeader			 100.00% (8/8)
 github.com/conformal/btcwire/msgalert.go	 MsgAlert.BtcDecode			 100.00% (8/8)
 github.com/conformal/btcwire/common.go		 readVarString				 100.00% (8/8)
-github.com/conformal/btcwire/msgpong.go		 MsgPong.BtcEncode			 100.00% (7/7)
+github.com/conformal/btcwire/msgalert.go	 MsgAlert.BtcEncode			 100.00% (8/8)
-github.com/conformal/btcwire/common.go		 randomUint64				 100.00% (7/7)
+github.com/conformal/btcwire/blockheader.go	 writeBlockHeader			 100.00% (8/8)
 github.com/conformal/btcwire/common.go		 writeVarString				 100.00% (7/7)
-github.com/conformal/btcwire/msgversion.go	 NewMsgVersionFromConn			 100.00% (7/7)
-github.com/conformal/btcwire/msgpong.go		 MsgPong.BtcDecode			 100.00% (7/7)
 github.com/conformal/btcwire/message.go		 readMessageHeader			 100.00% (7/7)
 github.com/conformal/btcwire/common.go		 DoubleSha256				 100.00% (7/7)
-github.com/conformal/btcwire/shahash.go		 NewShaHash				 100.00% (5/5)
+github.com/conformal/btcwire/common.go		 randomUint64				 100.00% (7/7)
-github.com/conformal/btcwire/common.go		 writeElements				 100.00% (5/5)
+github.com/conformal/btcwire/msgpong.go		 MsgPong.BtcEncode			 100.00% (7/7)
+github.com/conformal/btcwire/msgversion.go	 NewMsgVersionFromConn			 100.00% (7/7)
+github.com/conformal/btcwire/msgpong.go		 MsgPong.BtcDecode			 100.00% (7/7)
+github.com/conformal/btcwire/blockheader.go	 BlockHeader.BlockSha			 100.00% (5/5)
 github.com/conformal/btcwire/msginv.go		 MsgInv.AddInvVect			 100.00% (5/5)
 github.com/conformal/btcwire/msgnotfound.go	 MsgNotFound.AddInvVect			 100.00% (5/5)
 github.com/conformal/btcwire/msgping.go		 MsgPing.BtcDecode			 100.00% (5/5)
@@ -48,33 +49,34 @@ github.com/conformal/btcwire/msgping.go		 MsgPing.BtcEncode			 100.00% (5/5)
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.TxShas			 100.00% (5/5)
 github.com/conformal/btcwire/common.go		 readElements				 100.00% (5/5)
 github.com/conformal/btcwire/msgtx.go		 MsgTx.TxSha				 100.00% (5/5)
+github.com/conformal/btcwire/shahash.go		 NewShaHash				 100.00% (5/5)
 github.com/conformal/btcwire/shahash.go		 ShaHash.SetBytes			 100.00% (5/5)
-github.com/conformal/btcwire/blockheader.go	 BlockHeader.BlockSha			 100.00% (5/5)
 github.com/conformal/btcwire/netaddress.go	 NewNetAddress				 100.00% (5/5)
 github.com/conformal/btcwire/msggetblocks.go	 MsgGetBlocks.AddBlockLocatorHash	 100.00% (5/5)
-github.com/conformal/btcwire/msgaddr.go		 MsgAddr.AddAddress			 100.00% (5/5)
 github.com/conformal/btcwire/msggetdata.go	 MsgGetData.AddInvVect			 100.00% (5/5)
+github.com/conformal/btcwire/msgaddr.go		 MsgAddr.AddAddress			 100.00% (5/5)
 github.com/conformal/btcwire/msggetheaders.go	 MsgGetHeaders.AddBlockLocatorHash	 100.00% (5/5)
 github.com/conformal/btcwire/msgaddr.go		 MsgAddr.AddAddresses			 100.00% (5/5)
 github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.AddBlockHeader		 100.00% (5/5)
-github.com/conformal/btcwire/shahash.go		 ShaHash.String				 100.00% (4/4)
+github.com/conformal/btcwire/common.go		 writeElements				 100.00% (5/5)
-github.com/conformal/btcwire/invvect.go		 writeInvVect				 100.00% (4/4)
 github.com/conformal/btcwire/netaddress.go	 maxNetAddressPayload			 100.00% (4/4)
 github.com/conformal/btcwire/invvect.go		 readInvVect				 100.00% (4/4)
-github.com/conformal/btcwire/msgmempool.go	 MsgMemPool.BtcDecode			 100.00% (4/4)
-github.com/conformal/btcwire/msgping.go		 MsgPing.MaxPayloadLength		 100.00% (4/4)
-github.com/conformal/btcwire/msgpong.go		 MsgPong.MaxPayloadLength		 100.00% (4/4)
 github.com/conformal/btcwire/msgmempool.go	 MsgMemPool.BtcEncode			 100.00% (4/4)
+github.com/conformal/btcwire/msgpong.go		 MsgPong.MaxPayloadLength		 100.00% (4/4)
+github.com/conformal/btcwire/msgping.go		 MsgPing.MaxPayloadLength		 100.00% (4/4)
+github.com/conformal/btcwire/msgmempool.go	 MsgMemPool.BtcDecode			 100.00% (4/4)
+github.com/conformal/btcwire/invvect.go		 writeInvVect				 100.00% (4/4)
+github.com/conformal/btcwire/shahash.go		 ShaHash.String				 100.00% (4/4)
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.AddTransaction		 100.00% (3/3)
-github.com/conformal/btcwire/invvect.go		 InvType.String				 100.00% (3/3)
-github.com/conformal/btcwire/error.go		 MessageError.Error			 100.00% (3/3)
-github.com/conformal/btcwire/shahash.go		 ShaHash.Bytes				 100.00% (3/3)
-github.com/conformal/btcwire/msgaddr.go		 MsgAddr.MaxPayloadLength		 100.00% (3/3)
 github.com/conformal/btcwire/netaddress.go	 NetAddress.HasService			 100.00% (3/3)
 github.com/conformal/btcwire/msgversion.go	 MsgVersion.HasService			 100.00% (3/3)
-github.com/conformal/btcwire/netaddress.go	 NetAddress.SetAddress			 100.00% (2/2)
+github.com/conformal/btcwire/shahash.go		 ShaHash.Bytes				 100.00% (3/3)
+github.com/conformal/btcwire/invvect.go		 InvType.String				 100.00% (3/3)
+github.com/conformal/btcwire/error.go		 MessageError.Error			 100.00% (3/3)
+github.com/conformal/btcwire/msgaddr.go		 MsgAddr.MaxPayloadLength		 100.00% (3/3)
 github.com/conformal/btcwire/msgblock.go	 MsgBlock.ClearTransactions		 100.00% (2/2)
-github.com/conformal/btcwire/invvect.go		 NewInvVect				 100.00% (1/1)
+github.com/conformal/btcwire/netaddress.go	 NetAddress.SetAddress			 100.00% (2/2)
+github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.Command			 100.00% (1/1)
 github.com/conformal/btcwire/blockheader.go	 NewBlockHeader				 100.00% (1/1)
 github.com/conformal/btcwire/common.go		 readElement				 100.00% (1/1)
 github.com/conformal/btcwire/common.go		 writeElement				 100.00% (1/1)
@@ -104,7 +106,6 @@ github.com/conformal/btcwire/msggetdata.go	 NewMsgGetData				 100.00% (1/1)
 github.com/conformal/btcwire/msggetheaders.go	 MsgGetHeaders.Command			 100.00% (1/1)
 github.com/conformal/btcwire/msggetheaders.go	 MsgGetHeaders.MaxPayloadLength		 100.00% (1/1)
 github.com/conformal/btcwire/msggetheaders.go	 NewMsgGetHeaders			 100.00% (1/1)
-github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.Command			 100.00% (1/1)
 github.com/conformal/btcwire/msgheaders.go	 MsgHeaders.MaxPayloadLength		 100.00% (1/1)
 github.com/conformal/btcwire/msgheaders.go	 NewMsgHeaders				 100.00% (1/1)
 github.com/conformal/btcwire/msginv.go		 MsgInv.Command				 100.00% (1/1)
@@ -139,15 +140,14 @@ github.com/conformal/btcwire/msgversion.go	 MsgVersion.MaxPayloadLength		 100.00
 github.com/conformal/btcwire/msgversion.go	 NewMsgVersion				 100.00% (1/1)
 github.com/conformal/btcwire/netaddress.go	 NetAddress.AddService			 100.00% (1/1)
 github.com/conformal/btcwire/shahash.go		 ShaHash.IsEqual			 100.00% (1/1)
+github.com/conformal/btcwire/invvect.go		 NewInvVect				 100.00% (1/1)
 github.com/conformal/btcwire/msgtx.go		 MsgTx.BtcDecode			 80.00% (20/25)
 github.com/conformal/btcwire/msgtx.go		 MsgTx.BtcEncode			 78.26% (18/23)
 github.com/conformal/btcwire/msgtx.go		 readTxIn				 76.47% (13/17)
 github.com/conformal/btcwire/msgtx.go		 readTxOut				 75.00% (9/12)
-github.com/conformal/btcwire/msgtx.go		 writeOutPoint				 75.00% (3/4)
 github.com/conformal/btcwire/msgtx.go		 readOutPoint				 75.00% (3/4)
+github.com/conformal/btcwire/msgtx.go		 writeOutPoint				 75.00% (3/4)
 github.com/conformal/btcwire/msgtx.go		 writeTxIn				 73.33% (11/15)
 github.com/conformal/btcwire/msgtx.go		 writeTxOut				 72.73% (8/11)
-github.com/conformal/btcwire/msgversion.go	 MsgVersion.BtcDecode			 68.00% (17/25)
+github.com/conformal/btcwire			 ---------------------------------	 97.18% (897/923)
-github.com/conformal/btcwire/msgversion.go	 MsgVersion.BtcEncode			 63.64% (14/22)
-github.com/conformal/btcwire			 ---------------------------------	 95.45% (881/923)