fix: let a shortcode be typed as inline code

Converting :name: right after an unclosed backtick deleted the opening
backtick, so `:name:` could never be typed as a code span. The swap now
skips a shortcode preceded by an unclosed backtick, leaving the text for
the code input rule to close; code text is already exempt everywhere.
An emoji picked from the popup still drops the dangling backtick, since
inline code cannot close across the emoji.

Author: nikkothari22

apps/web/src/components/features/editor/customEmoji.ts

@@ -37,7 +37,8 @@ export const CustomEmoji = Node.create({
     renderText: ({ node }) => node.attrs.alt ?? "",
 
     // A known `:name:` is always the emoji: typed, pasted, or already in a draft or a
-    // message being edited.
+    // message being edited. Exception: after an unclosed backtick it stays text, so
+    // `:name:` can be typed as inline code.
     addProseMirrorPlugins() {
         return [
             new Plugin({

apps/web/src/components/features/editor/customEmojiInput.test.ts

@@ -46,8 +46,8 @@ getDefaultStore().set(customEmojiCategoriesAtom, [
 ])
 
 describe("customEmojiInputTransaction", () => {
-    it("swaps a typed shortcode and drops the unclosed backtick before it", () => {
-        expect(show(run(stateOf(text("run `:party")), (tr) => tr.insertText(":", 12)))).toBe("run [party]")
+    it("leaves a shortcode after an unclosed backtick, so inline code can close", () => {
+        expect(show(run(stateOf(text("run `:party")), (tr) => tr.insertText(":", 12)))).toBe("run `:party:")
     })
 
     it("keeps a closed pair of backticks", () => {

apps/web/src/components/features/editor/customEmojiInput.ts

@@ -47,8 +47,11 @@ const changedRanges = (doc: PMNode, transactions?: readonly Transaction[]): [num
 }
 
 /**
- * Swaps each known `:name:` in the changed paragraphs for its emoji (code keeps it), and
- * drops the unclosed backtick before each emoji added, as that inline code could never close.
+ * Swaps each known `:name:` in the changed paragraphs for its emoji — except in code,
+ * and except after an unclosed backtick: the writer may be typing the shortcode as
+ * inline code, so the text stays for the code input rule to close. An emoji the picker
+ * or popup inserts still drops the unclosed backtick before it, as that inline code
+ * can no longer close across the emoji.
  * Without `transactions`, checks the whole document. Null when nothing changes.
  */
 export const customEmojiInputTransaction = (
@@ -73,8 +76,12 @@ export const customEmojiInputTransaction = (
                 for (const part of splitCustomEmojiShortcodes(child.text ?? "", shortcodes) ?? []) {
                     if (typeof part === "string") at += part.length
                     else {
-                        swaps.push({ from: at, to: at + part.shortcode.length, marks: child.marks, ...part })
-                        added.add(at)
+                        // After an unclosed backtick, keep the text: the writer may be
+                        // closing `:name:` into inline code.
+                        if (unclosedBacktick(state.doc, at) === null) {
+                            swaps.push({ from: at, to: at + part.shortcode.length, marks: child.marks, ...part })
+                            added.add(at)
+                        }
                         at += part.shortcode.length
                     }
                 }