Start moving to a common set of test cases

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "testcases"]
+	path = testcases
+	url = https://github.com/go-irc/irc-parser-tests/

.travis.yml

@@ -9,6 +9,8 @@ before_install:
   # Linting deps
   - go get github.com/alecthomas/gometalinter
   - gometalinter --install
+  # Remove the go file from the test cases dir as it fails linting
+  - rm ./testcases/*.go
 
 script:
   - gometalinter --fast ./... -D gas

README.md

@@ -33,6 +33,11 @@ As a result of this, there are multiple import locations.
   tagged as stable
 * `github.com/go-irc/irc` should be used to develop against the master branch
 
+## Development
+
+In order to run the tests, make sure all submodules are up to date. If you are
+just using this library, these are not needed.
+
 ## Example
 
 ```go

client_test.go

@@ -120,7 +120,7 @@ func TestClientHandler(t *testing.T) {
 	})
 
 	assert.EqualValues(t, []*Message{
-		&Message{
+		{
 			Tags:    Tags{},
 			Prefix:  &Prefix{},
 			Command: "001",
@@ -133,7 +133,7 @@ func TestClientHandler(t *testing.T) {
 	err = c.Run()
 	assert.Equal(t, io.EOF, err)
 	assert.EqualValues(t, []*Message{
-		&Message{
+		{
 			Tags:    Tags{},
 			Prefix:  &Prefix{Name: "world"},
 			Command: "CTCP",
@@ -147,7 +147,7 @@ func TestClientHandler(t *testing.T) {
 	err = c.Run()
 	assert.Equal(t, io.EOF, err)
 	assert.EqualValues(t, []*Message{
-		&Message{
+		{
 			Tags:    Tags{},
 			Prefix:  &Prefix{Name: "world"},
 			Command: "PRIVMSG",

parser.go

@@ -59,15 +59,16 @@ func ParseTagValue(v string) TagValue {
 
 		if c == '\\' {
 			c2, _, err := input.ReadRune()
+
+			// If we got a backslash then the end of the tag value, we should
+			// just ignore the backslash.
 			if err != nil {
-				ret.WriteRune(c)
 				break
 			}
 
 			if replacement, ok := tagDecodeSlashMap[c2]; ok {
 				ret.WriteRune(replacement)
 			} else {
-				ret.WriteRune(c)
 				ret.WriteRune(c2)
 			}
 		} else {
@@ -305,6 +306,12 @@ func ParseMessage(line string) (*Message, error) {
 	c.Command = strings.ToUpper(c.Params[0])
 	c.Params = c.Params[1:]
 
+	// If there are no params, set it to nil, to make writing tests and other
+	// things simpler.
+	if len(c.Params) == 0 {
+		c.Params = nil
+	}
+
 	return c, nil
 }
 
@@ -354,6 +361,11 @@ func (m *Message) Copy() *Message {
 	// Copy the Params slice
 	newMessage.Params = append(make([]string, 0, len(m.Params)), m.Params...)
 
+	// Similar to parsing, if Params is empty, set it to nil
+	if len(newMessage.Params) == 0 {
+		newMessage.Params = nil
+	}
+
 	return newMessage
 }