Track performance of message sends

ts/components/CompositionInput.tsx

@@ -74,7 +74,11 @@ export type Props = {
   ): unknown;
   onTextTooLong(): unknown;
   onPickEmoji(o: EmojiPickDataType): unknown;
-  onSubmit(message: string, mentions: Array<BodyRangeType>): unknown;
+  onSubmit(
+    message: string,
+    mentions: Array<BodyRangeType>,
+    timestamp: number
+  ): unknown;
   getQuotedMessage(): unknown;
   clearQuotedMessage(): unknown;
 };
@@ -218,6 +222,7 @@ export const CompositionInput: React.ComponentType<Props> = props => {
   };
 
   const submit = () => {
+    const timestamp = Date.now();
     const quill = quillRef.current;
 
     if (quill === undefined) {
@@ -226,8 +231,10 @@ export const CompositionInput: React.ComponentType<Props> = props => {
 
     const [text, mentions] = getTextAndMentions();
 
-    window.log.info(`Submitting a message with ${mentions.length} mentions`);
-    onSubmit(text, mentions);
+    window.log.info(
+      `CompositionInput: Submitting message ${timestamp} with ${mentions.length} mentions`
+    );
+    onSubmit(text, mentions, timestamp);
   };
 
   if (inputApi) {

ts/components/conversation/Message.tsx

@@ -454,7 +454,7 @@ export class Message extends React.Component<Props, State> {
   }
 
   public componentDidUpdate(prevProps: Props): void {
-    const { canDeleteForEveryone, isSelected } = this.props;
+    const { canDeleteForEveryone, isSelected, status, timestamp } = this.props;
 
     this.startSelectedTimer();
 
@@ -468,6 +468,19 @@ export class Message extends React.Component<Props, State> {
     if (canDeleteForEveryone !== prevProps.canDeleteForEveryone) {
       this.startDeleteForEveryoneTimer();
     }
+
+    if (
+      prevProps.status === 'sending' &&
+      (status === 'sent' ||
+        status === 'delivered' ||
+        status === 'read' ||
+        status === 'viewed')
+    ) {
+      const delta = Date.now() - timestamp;
+      window.log.info(
+        `Message.tsx: Rendered 'send complete' for message ${timestamp}; took ${delta}ms`
+      );
+    }
   }
 
   public checkForHeightChange(prevProps: Props): void {