Merge pull request #169 from segmentio/jeremy/remove-internal-message

Remove message internal-only restriction and add ValidateFields

alias.go

@@ -19,10 +19,6 @@ type Alias struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Alias) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Alias) Validate() error {
 	if len(msg.UserId) == 0 {
 		return FieldError{

analytics.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"strconv"
 	"sync"
 
 	"bytes"
@@ -14,7 +15,6 @@ import (
 
 // Version of the client.
 const Version = "3.0.0"
-const unimplementedError = "not implemented"
 
 // This interface is the main API exposed by the analytics package.
 // Values that satsify this interface are returned by the client constructors
@@ -291,7 +291,7 @@ func (c *client) upload(b []byte) error {
 
 	req.Header.Add("User-Agent", "analytics-go (version: "+Version+")")
 	req.Header.Add("Content-Type", "application/json")
-	req.Header.Add("Content-Length", string(len(b)))
+	req.Header.Add("Content-Length", strconv.Itoa(len(b)))
 	req.SetBasicAuth(c.key, "")
 
 	res, err := c.http.Do(req)

analytics_test.go

@@ -67,13 +67,11 @@ func (l testLogger) Errorf(format string, args ...interface{}) {
 }
 
 var _ Message = (*testErrorMessage)(nil)
+
 // Instances of this type are used to force message validation errors in unit
 // tests.
 type testErrorMessage struct{}
 
-func (m testErrorMessage) internal() {
-}
-
 func (m testErrorMessage) Validate() error { return testError }
 
 var (
@@ -336,9 +334,6 @@ var _ Message = (*customMessage)(nil)
 type customMessage struct {
 }
 
-func (c *customMessage) internal() {
-}
-
 func (c *customMessage) Validate() error {
 	return nil
 }

group.go

@@ -21,10 +21,6 @@ type Group struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Group) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Group) Validate() error {
 	if len(msg.GroupId) == 0 {
 		return FieldError{

identify.go

@@ -20,10 +20,6 @@ type Identify struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Identify) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Identify) Validate() error {
 	if len(msg.UserId) == 0 && len(msg.AnonymousId) == 0 {
 		return FieldError{

message.go

@@ -36,9 +36,6 @@ type Message interface {
 	// Validate validates the internal structure of the message, the method must return
 	// nil if the message is valid, or an error describing what went wrong.
 	Validate() error
-
-	// internal is an unexposed interface function to ensure only types defined within this package can satisfy the Message interface. Invoking this method will panic.
-	internal()
 }
 
 // Takes a message id as first argument and returns it, unless it's the zero-

page.go

@@ -21,10 +21,6 @@ type Page struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Page) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Page) Validate() error {
 	if len(msg.UserId) == 0 && len(msg.AnonymousId) == 0 {
 		return FieldError{

screen.go

@@ -21,10 +21,6 @@ type Screen struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Screen) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Screen) Validate() error {
 	if len(msg.UserId) == 0 && len(msg.AnonymousId) == 0 {
 		return FieldError{

track.go

@@ -21,10 +21,6 @@ type Track struct {
 	Integrations Integrations `json:"integrations,omitempty"`
 }
 
-func (msg Track) internal() {
-	panic(unimplementedError)
-}
-
 func (msg Track) Validate() error {
 	if len(msg.Event) == 0 {
 		return FieldError{

validate.go

@@ -0,0 +1,65 @@
+package analytics
+
+type FieldGetter interface {
+	GetField(field string) (interface{}, bool)
+}
+
+func getString(msg FieldGetter, field string) string {
+	if val, ok := msg.GetField(field); ok {
+		if str, ok := val.(string); ok {
+			return str
+		}
+	}
+	return ""
+}
+
+func ValidateFields(msg FieldGetter) error {
+	typ, _ := msg.GetField("type")
+	if str, ok := typ.(string); ok {
+		switch str {
+		case "alias":
+			return Alias{
+				Type:       "alias",
+				UserId:     getString(msg, "userId"),
+				PreviousId: getString(msg, "previousId"),
+			}.Validate()
+		case "group":
+			return Group{
+				Type:        "group",
+				UserId:      getString(msg, "userId"),
+				AnonymousId: getString(msg, "anonymousId"),
+				GroupId:     getString(msg, "groupId"),
+			}.Validate()
+		case "identify":
+			return Identify{
+				Type:        "identify",
+				UserId:      getString(msg, "userId"),
+				AnonymousId: getString(msg, "anonymousId"),
+			}.Validate()
+		case "page":
+			return Page{
+				Type:        "page",
+				UserId:      getString(msg, "userId"),
+				AnonymousId: getString(msg, "anonymousId"),
+			}.Validate()
+		case "screen":
+			return Screen{
+				Type:        "screen",
+				UserId:      getString(msg, "userId"),
+				AnonymousId: getString(msg, "anonymousId"),
+			}.Validate()
+		case "track":
+			return Track{
+				Type:        "track",
+				UserId:      getString(msg, "userId"),
+				AnonymousId: getString(msg, "anonymousId"),
+				Event:       getString(msg, "event"),
+			}.Validate()
+		}
+	}
+	return FieldError{
+		Type:  "analytics.Event",
+		Name:  "Type",
+		Value: typ,
+	}
+}