Fixed SendComplex

api/message.go

@@ -1,7 +1,7 @@
 package api
 
 import (
-	"io"
+	"mime/multipart"
 
 	"github.com/diamondburned/arikawa/discord"
 	"github.com/diamondburned/arikawa/internal/httputil"
@@ -132,12 +132,11 @@ func (c *Client) SendMessageComplex(
 			httputil.WithJSONBody(c, data))
 	}
 
-	writer := func(w io.Writer) error {
-		return data.WriteMultipart(c, w)
+	writer := func(mw *multipart.Writer) error {
+		return data.WriteMultipart(c, mw)
 	}
 
-	resp, err := c.MeanwhileBody(writer, "POST", URL,
-		httputil.MultipartRequest)
+	resp, err := c.MeanwhileMultipart(writer, "POST", URL)
 	if err != nil {
 		return nil, err
 	}

api/message_send.go

@@ -1,12 +1,8 @@
 package api
 
 import (
-	"fmt"
 	"io"
-	"log"
 	"mime/multipart"
-	"net/http"
-	"net/textproto"
 	"strconv"
 	"strings"
 
@@ -15,12 +11,13 @@ import (
 	"github.com/pkg/errors"
 )
 
+const AttachmentSpoilerPrefix = "SPOILER_"
+
 var quoteEscaper = strings.NewReplacer(`\`, `\\`, `"`, `\"`)
 
 type SendMessageFile struct {
-	Name        string
-	ContentType string // auto-detect if empty
-	Reader      io.Reader
+	Name   string
+	Reader io.Reader
 }
 
 type SendMessageData struct {
@@ -34,9 +31,9 @@ type SendMessageData struct {
 }
 
 func (data *SendMessageData) WriteMultipart(
-	c json.Driver, w io.Writer) error {
+	c json.Driver, body *multipart.Writer) error {
 
-	return writeMultipart(c, w, data, data.Files)
+	return writeMultipart(c, body, data, data.Files)
 }
 
 type ExecuteWebhookData struct {
@@ -47,87 +44,39 @@ type ExecuteWebhookData struct {
 }
 
 func (data *ExecuteWebhookData) WriteMultipart(
-	c json.Driver, w io.Writer) error {
+	c json.Driver, body *multipart.Writer) error {
 
-	return writeMultipart(c, w, data, data.Files)
+	return writeMultipart(c, body, data, data.Files)
 }
 
 func writeMultipart(
-	c json.Driver, w io.Writer,
+	c json.Driver, body *multipart.Writer,
 	item interface{}, files []SendMessageFile) error {
 
-	body := multipart.NewWriter(w)
+	defer body.Close()
 
 	// Encode the JSON body first
-	h := textproto.MIMEHeader{}
-	h.Set("Content-Disposition", `form-data; name="payload_json"`)
-	h.Set("Content-Type", "application/json")
-
-	w, err := body.CreatePart(h)
+	w, err := body.CreateFormField("payload_json")
 	if err != nil {
 		return errors.Wrap(err, "Failed to create bodypart for JSON")
 	}
 
-	j, err := c.Marshal(item)
-	log.Println(string(j), err)
-
 	if err := c.EncodeStream(w, item); err != nil {
 		return errors.Wrap(err, "Failed to encode JSON")
 	}
 
-	// Content-Type buffer
-	var buf []byte
-
 	for i, file := range files {
-		h := textproto.MIMEHeader{}
-		h.Set("Content-Disposition", fmt.Sprintf(
-			`form-data; name="file%d"; filename="%s"`,
-			i, quoteEscaper.Replace(file.Name),
-		))
+		num := strconv.Itoa(i)
 
-		var bufUsed int
-
-		if file.ContentType == "" {
-			if buf == nil {
-				buf = make([]byte, 512)
-			}
-
-			n, err := file.Reader.Read(buf)
-			if err != nil {
-				return errors.Wrap(err, "Failed to read first 512 bytes for "+
-					strconv.Itoa(i))
-			}
-
-			file.ContentType = http.DetectContentType(buf[:n])
-			files[i] = file
-			bufUsed = n
-		}
-
-		h.Set("Content-Type", file.ContentType)
-
-		w, err := body.CreatePart(h)
+		w, err := body.CreateFormFile("file"+num, file.Name)
 		if err != nil {
-			return errors.Wrap(err, "Failed to create bodypart for "+
-				strconv.Itoa(i))
-		}
-
-		if bufUsed > 0 {
-			// Prematurely write
-			if _, err := w.Write(buf[:bufUsed]); err != nil {
-				return errors.Wrap(err, "Failed to write buffer for "+
-					strconv.Itoa(i))
-			}
+			return errors.Wrap(err, "Failed to create bodypart for "+num)
 		}
 
 		if _, err := io.Copy(w, file.Reader); err != nil {
-			return errors.Wrap(err, "Failed to write file for "+
-				strconv.Itoa(i))
+			return errors.Wrap(err, "Failed to write for file "+num)
 		}
 	}
 
-	if err := body.Close(); err != nil {
-		return errors.Wrap(err, "Failed to close body writer")
-	}
-
 	return nil
 }

api/webhook.go

@@ -1,7 +1,7 @@
 package api
 
 import (
-	"io"
+	"mime/multipart"
 	"net/url"
 
 	"github.com/diamondburned/arikawa/discord"
@@ -120,11 +120,11 @@ func (c *Client) ExecuteWebhook(
 			httputil.WithJSONBody(c, data))
 	}
 
-	writer := func(w io.Writer) error {
-		return data.WriteMultipart(c, w)
+	writer := func(mw *multipart.Writer) error {
+		return data.WriteMultipart(c, mw)
 	}
 
-	resp, err := c.MeanwhileBody(writer, "POST", URL)
+	resp, err := c.MeanwhileMultipart(writer, "POST", URL)
 	if err != nil {
 		return nil, err
 	}

internal/httputil/client.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
+	"mime/multipart"
 	"net/http"
 	"time"
 
@@ -31,7 +32,8 @@ func NewClient() Client {
 	}
 }
 
-func (c *Client) MeanwhileBody(bodyWriter func(io.Writer) error,
+func (c *Client) MeanwhileMultipart(
+	multipartWriter func(*multipart.Writer) error,
 	method, url string, opts ...RequestOption) (*http.Response, error) {
 
 	// We want to cancel the request if our bodyWriter fails
@@ -39,11 +41,12 @@ func (c *Client) MeanwhileBody(bodyWriter func(io.Writer) error,
 	defer cancel()
 
 	r, w := io.Pipe()
+	body := multipart.NewWriter(w)
 
 	var bgErr error
 
 	go func() {
-		if err := bodyWriter(w); err != nil {
+		if err := multipartWriter(body); err != nil {
 			bgErr = err
 			cancel()
 		}
@@ -53,7 +56,10 @@ func (c *Client) MeanwhileBody(bodyWriter func(io.Writer) error,
 	}()
 
 	resp, err := c.RequestCtx(ctx, method, url,
-		append([]RequestOption{WithBody(r)}, opts...)...)
+		append([]RequestOption{
+			WithBody(r),
+			WithContentType(body.FormDataContentType()),
+		}, opts...)...)
 
 	if err != nil && bgErr != nil {
 		if resp.Body != nil {

internal/httputil/options.go

@@ -21,6 +21,13 @@ func MultipartRequest(r *http.Request) error {
 	return nil
 }
 
+func WithContentType(ctype string) RequestOption {
+	return func(r *http.Request) error {
+		r.Header.Set("Content-Type", ctype)
+		return nil
+	}
+}
+
 func WithSchema(schema SchemaEncoder, v interface{}) RequestOption {
 	return func(r *http.Request) error {
 		params, err := schema.Encode(v)