Show hover cards for inline message emoji (#885)

Signed-off-by: Wes <wesbillman@users.noreply.github.com>
Co-authored-by: Pinky <44b8e82baa6e0e254e0208d68f335c283c94e7b78dd1fa10d5a49d3f13dd0435@sprout-oss.stage.blox.sqprod.co>

desktop/src/shared/ui/markdown.tsx

@@ -40,6 +40,7 @@ import remarkCustomEmoji, {
 import remarkMentions from "@/shared/lib/remarkMentions";
 import remarkMessageLinks from "@/features/messages/lib/remarkMessageLinks";
 import { Button } from "@/shared/ui/button";
+import { Popover, PopoverContent, PopoverTrigger } from "@/shared/ui/popover";
 import { Tooltip, TooltipContent, TooltipTrigger } from "@/shared/ui/tooltip";
 
 import {
@@ -306,6 +307,97 @@ function getCodeBlockText(children: React.ReactNode) {
   return getReactNodeText(children).replace(/\n$/, "");
 }
 
+function InlineEmojiPopover({
+  alt,
+  resolvedSrc,
+}: {
+  alt: string | undefined;
+  resolvedSrc: string;
+}) {
+  const [open, setOpen] = React.useState(false);
+  const openTimeout = React.useRef<ReturnType<typeof setTimeout> | null>(null);
+  const closeTimeout = React.useRef<ReturnType<typeof setTimeout> | null>(null);
+  const label = alt?.trim() || "Custom emoji";
+
+  const clearTimers = React.useCallback(() => {
+    if (openTimeout.current) {
+      clearTimeout(openTimeout.current);
+      openTimeout.current = null;
+    }
+    if (closeTimeout.current) {
+      clearTimeout(closeTimeout.current);
+      closeTimeout.current = null;
+    }
+  }, []);
+
+  const handleMouseEnter = React.useCallback(() => {
+    clearTimers();
+    openTimeout.current = setTimeout(() => setOpen(true), 200);
+  }, [clearTimers]);
+
+  const scheduleClose = React.useCallback(() => {
+    clearTimers();
+    closeTimeout.current = setTimeout(() => setOpen(false), 150);
+  }, [clearTimers]);
+
+  const handleFocus = React.useCallback(() => {
+    clearTimers();
+    setOpen(true);
+  }, [clearTimers]);
+
+  React.useEffect(() => clearTimers, [clearTimers]);
+
+  return (
+    <Popover open={open} onOpenChange={setOpen}>
+      <PopoverTrigger asChild>
+        <button
+          type="button"
+          className="inline-flex border-0 bg-transparent p-0 align-baseline text-inherit"
+          aria-label={label}
+          onMouseEnter={handleMouseEnter}
+          onMouseLeave={scheduleClose}
+          onFocus={handleFocus}
+          onBlur={scheduleClose}
+        >
+          <img
+            alt={alt}
+            title={label}
+            src={resolvedSrc}
+            data-custom-emoji=""
+            className="mx-px inline-block h-[1.25em] w-auto max-w-none align-text-bottom"
+            draggable={false}
+            onContextMenu={(e) => e.preventDefault()}
+          />
+        </button>
+      </PopoverTrigger>
+      <PopoverContent
+        align="center"
+        side="top"
+        sideOffset={6}
+        className="w-auto min-w-32 max-w-56 rounded-xl p-3"
+        onMouseEnter={handleMouseEnter}
+        onMouseLeave={scheduleClose}
+        onOpenAutoFocus={(e) => e.preventDefault()}
+        onCloseAutoFocus={(e) => e.preventDefault()}
+      >
+        <div className="flex flex-col items-center text-center">
+          <div className="mb-2 flex h-14 w-14 items-center justify-center">
+            <img
+              alt={alt}
+              src={resolvedSrc}
+              className="inline-block h-12 w-12 object-contain"
+              draggable={false}
+            />
+          </div>
+          <div className="max-w-[12rem] text-balance text-sm font-semibold leading-snug text-popover-foreground">
+            {label}
+          </div>
+        </div>
+      </PopoverContent>
+    </Popover>
+  );
+}
+
 function MarkdownCodeBlock({
   children,
   language,
@@ -839,18 +931,10 @@ function createMarkdownComponents(
       if (!resolvedSrc) {
         return <span>{alt}</span>;
       }
-      // Inline custom emoji: sized to the line, baseline-aligned with text.
-      return (
-        <img
-          alt={alt}
-          title={alt}
-          src={resolvedSrc}
-          data-custom-emoji=""
-          className="mx-px inline-block h-[1.25em] w-auto max-w-none align-text-bottom"
-          draggable={false}
-          onContextMenu={(e) => e.preventDefault()}
-        />
-      );
+      if (!interactive) {
+        return <span>{alt}</span>;
+      }
+      return <InlineEmojiPopover alt={alt} resolvedSrc={resolvedSrc} />;
     },
     "channel-link": ({ children }: { children?: React.ReactNode }) => {
       const text = String(children ?? "");

desktop/tests/e2e/custom-emoji.spec.ts

@@ -90,6 +90,8 @@ test("custom emoji round-trips through select-all + send to the timeline", async
     .getByTestId("message-timeline")
     .locator(`img[data-custom-emoji][alt=":${SHORTCODE}:"]`);
   await expect(sentEmoji.last()).toBeVisible();
+  await sentEmoji.last().hover();
+  await expect(page.getByText(`:${SHORTCODE}:`).last()).toBeVisible();
   // The composer clears after send.
   await expect(input.locator("img[data-custom-emoji]")).toHaveCount(0);
 });