Add embedded urls attribute to live thread updates

Signed-off-by: Vartan Benohanian <vartanbeno@gmail.com>

reddit/live-thread.go

@@ -36,7 +36,7 @@ type LiveThread struct {
 	ViewerCount       int    `json:"viewer_count"`
 	ViewerCountFuzzed bool   `json:"viewer_count_fuzzed"`
 
-	// Empty when a list thread has ended.
+	// Empty when a live thread has ended.
 	WebSocketURL string `json:"websocket_url,omitempty"`
 
 	Announcement bool `json:"is_announcement"`
@@ -51,11 +51,45 @@ type LiveThreadUpdate struct {
 	Created *Timestamp `json:"created_utc,omitempty"`
 
 	Body         string   `json:"body,omitempty"`
-	// todo: add "embeds" field?
-
+	EmbeddedURLs []string `json:"embeds,omitempty"`
 	Stricken     bool     `json:"stricken"`
 }
 
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (u *LiveThreadUpdate) UnmarshalJSON(b []byte) error {
+	root := new(struct {
+		ID      string     `json:"id"`
+		FullID  string     `json:"name"`
+		Author  string     `json:"author"`
+		Created *Timestamp `json:"created_utc"`
+
+		Body         string `json:"body"`
+		EmbeddedURLs []struct {
+			URL string `json:"url"`
+		} `json:"embeds"`
+		Stricken bool `json:"stricken"`
+	})
+
+	err := json.Unmarshal(b, root)
+	if err != nil {
+		return err
+	}
+
+	u.ID = root.ID
+	u.FullID = root.FullID
+	u.Author = root.Author
+	u.Created = root.Created
+
+	u.Body = root.Body
+	u.Stricken = root.Stricken
+
+	for _, eu := range root.EmbeddedURLs {
+		u.EmbeddedURLs = append(u.EmbeddedURLs, eu.URL)
+	}
+
+	return nil
+}
+
 // LiveThreadCreateOrUpdateRequest represents a request to create/update a live thread.
 type LiveThreadCreateOrUpdateRequest struct {
 	// No longer than 120 characters.
@@ -432,7 +466,6 @@ func (s *LiveThreadService) Accept(ctx context.Context, id string) (*Response, e
 }
 
 // Leave the live thread by abdicating your status as contributor.
-// todo: test as the author who leaves the thread.
 func (s *LiveThreadService) Leave(ctx context.Context, id string) (*Response, error) {
 	form := url.Values{}
 	form.Set("api_type", "json")

reddit/live-thread_test.go

@@ -76,6 +76,7 @@ var expectedLiveThreadUpdates = []*LiveThreadUpdate{
 		Created: &Timestamp{time.Date(2020, 9, 18, 4, 35, 24, 0, time.UTC)},
 
 		Body:         "test 2",
+		EmbeddedURLs: []string{"https://example.com", "https://reddit.com"},
 
 		Stricken: true,
 	},

testdata/live-thread/updates.json

@@ -11,7 +11,18 @@
           "name": "LiveUpdate_5e46cd94-f968-11ea-9a6a-0e1933241e7d",
           "mobile_embeds": [],
           "author": "testuser1",
-          "embeds": [],
+          "embeds": [
+            {
+              "url": "https://example.com",
+              "width": 485,
+              "height": 0
+            },
+            {
+              "url": "https://reddit.com",
+              "width": 485,
+              "height": 0
+            }
+          ],
           "created": 1600432524.0,
           "created_utc": 1600403724.0,
           "body_html": "<div class=\"md\"><p>test 2</p>\n</div>",