Moves determining content types into theme_client

This ensures that users of phoenix.LoadAsset will have the data
correctly loaded based on content type. Binary data will be set as
the attachment, compared to the value which was done previously.

Though, theme-watch pretty much has the same implementation of LoadAsset
which should be resolved in order to reduce unnecessary duplication.

fixes #11

load_asset_test.go

@@ -39,7 +39,7 @@ func (s *LoadAssetSuite) TestWhenAFileIsEmpty() {
 	assert.False(s.T(), asset.IsValid(), "The returned asset should not be considered valid")
 }
 
-func (s *LoadAssetSuite) TestWhenAFileContainsData() {
+func (s *LoadAssetSuite) TestWhenAFileContainsTextData() {
 	root, filename, err := s.allocateFile("hello world")
 	if err != nil {
 		log.Fatal(err)
@@ -48,6 +48,19 @@ func (s *LoadAssetSuite) TestWhenAFileContainsData() {
 	asset, err := LoadAsset(root, filename)
 	assert.Nil(s.T(), err, "There should not be an error returned")
 	assert.True(s.T(), asset.IsValid(), "Files that contain data should be valid")
+	assert.Equal(s.T(), "hello world", asset.Value)
+}
+
+func (s *LoadAssetSuite) TestWhenAFileContainsBinaryData() {
+	root, filename, err := s.allocateFile(string(BinaryTestData()))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	asset, err := LoadAsset(root, filename)
+	assert.Nil(s.T(), err, "There should not be an error returned")
+	assert.True(s.T(), asset.IsValid(), "Files that contain data should be valid")
+	assert.True(s.T(), len(asset.Attachment) > 0, "The attachment should not be blank")
 }
 
 func (s *LoadAssetSuite) TestWhenFileIsADirectory() {

theme_client.go

@@ -2,6 +2,7 @@ package phoenix
 
 import (
 	"crypto/tls"
+	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -50,10 +51,29 @@ func LoadAsset(root, filename string) (asset Asset, err error) {
 	if err != nil {
 		return
 	}
-	asset = Asset{Value: string(buffer), Key: filename}
+
+	asset = Asset{Key: filename}
+	if contentTypeFor(buffer) == "text" {
+		asset.Value = string(buffer)
+	} else {
+		asset.Attachment = encode64(buffer)
+	}
 	return
 }
 
+func contentTypeFor(data []byte) string {
+	contentType := http.DetectContentType(data)
+	if strings.Contains(contentType, "text") {
+		return "text"
+	} else {
+		return "binary"
+	}
+}
+
+func encode64(data []byte) string {
+	return base64.StdEncoding.EncodeToString(data)
+}
+
 type EventType int
 
 func (e EventType) String() string {

utils.go

@@ -1,7 +1,10 @@
 package phoenix
 
 import (
+	"bytes"
 	"fmt"
+	"image"
+	"image/png"
 	"io/ioutil"
 	"log"
 	"os"
@@ -32,3 +35,10 @@ func TestFixture(name string) string {
 	}
 	return string(bytes)
 }
+
+func BinaryTestData() []byte {
+	img := image.NewRGBA(image.Rect(0, 0, 10, 10))
+	buff := bytes.NewBuffer([]byte{})
+	png.Encode(buff, img)
+	return buff.Bytes()
+}