Change autosuggestions to include second word in web UI (#39622)

app/javascript/mastodon/components/autosuggest/utils.ts

@@ -0,0 +1,29 @@
+export const textAtCursorMatchesToken = (
+  str: string,
+  caretPosition: number,
+  searchTokens: string[],
+) => {
+  let word: string;
+
+  const regex = new RegExp(`[${searchTokens.join('')}\\w]+(\\s[\\w]+)?$`);
+  const left = str.slice(0, caretPosition).search(regex);
+  const right = str.slice(caretPosition).search(/\s/);
+
+  if (right < 0) {
+    word = str.slice(left);
+  } else {
+    word = str.slice(left, right + caretPosition);
+  }
+
+  word = word.trim();
+
+  if (word.length < 3 || (word[0] && !searchTokens.includes(word[0]))) {
+    return [null, null];
+  }
+
+  if (word.length > 0) {
+    return [left + 1, word];
+  } else {
+    return [null, null];
+  }
+};