From e5c8abab9e9e2c215972208f203ddbd53551a8cf Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Thu, 15 Jan 2026 00:27:27 +0000
Subject: [PATCH] fix: preserve markdown code fences

---
 src/markdown/ir.ts  | 13 ++++++++++---
 src/slack/format.ts | 18 +++++++++++++++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/markdown/ir.ts b/src/markdown/ir.ts
index 9dc3922b6..b9a537bbe 100644
--- a/src/markdown/ir.ts
+++ b/src/markdown/ir.ts
@@ -459,11 +459,18 @@ export function markdownToIR(markdown: string, options: MarkdownParseOptions = {
 
   const trimmedText = state.text.trimEnd();
   const trimmedLength = trimmedText.length;
+  let codeBlockEnd = 0;
+  for (const span of state.styles) {
+    if (span.style !== "code_block") continue;
+    if (span.end > codeBlockEnd) codeBlockEnd = span.end;
+  }
+  const finalLength = Math.max(trimmedLength, codeBlockEnd);
+  const finalText = finalLength === state.text.length ? state.text : state.text.slice(0, finalLength);
 
   return {
-    text: trimmedText,
-    styles: mergeStyleSpans(clampStyleSpans(state.styles, trimmedLength)),
-    links: clampLinkSpans(state.links, trimmedLength),
+    text: finalText,
+    styles: mergeStyleSpans(clampStyleSpans(state.styles, finalLength)),
+    links: clampLinkSpans(state.links, finalLength),
   };
 }
 
diff --git a/src/slack/format.ts b/src/slack/format.ts
index fddc014ec..575841921 100644
--- a/src/slack/format.ts
+++ b/src/slack/format.ts
@@ -24,7 +24,7 @@ function isAllowedSlackAngleToken(token: string): boolean {
   );
 }
 
-function escapeSlackMrkdwnText(text: string): string {
+function escapeSlackMrkdwnContent(text: string): string {
   if (!text.includes("&") && !text.includes("<") && !text.includes(">")) {
     return text;
   }
@@ -49,6 +49,22 @@ function escapeSlackMrkdwnText(text: string): string {
   return out.join("");
 }
 
+function escapeSlackMrkdwnText(text: string): string {
+  if (!text.includes("&") && !text.includes("<") && !text.includes(">")) {
+    return text;
+  }
+
+  return text
+    .split("\n")
+    .map((line) => {
+      if (line.startsWith("> ")) {
+        return `> ${escapeSlackMrkdwnContent(line.slice(2))}`;
+      }
+      return escapeSlackMrkdwnContent(line);
+    })
+    .join("\n");
+}
+
 function buildSlackLink(link: MarkdownLinkSpan, text: string) {
   const href = link.href.trim();
   if (!href) return null;